Youtube555

Physical Exercising

2007-09-27T16:10:00.000+02:00

Exercise Program Information:

Get Started with Your Exercise Program

Aerobic Exercise

Strength Training

Flexibility

Special Recommendations

(Children, Older Adults, Pregnancy, Obesity)

Stay With It!

Be More Physically Active

Nutrition

Body Composition

Topics of Special Interest:: "Do You Have to Burn Fat to Lose Fat?"; "Exercise and Delayed-Onset Muscle Soreness"; "Post-pregnancy Exercise"; "Massage and Recovery from Endurance Exercise"; "Lifestyle Modifications for Reducing Hypercholesterolemia"

If you don't know that regular exercise can help you live longer and reduce your risks for a host of diseases, then chances are you've been living under a rock. Come out from under!

Recent studies show:

Leisure-time physical activity is associated with a reduced risk of premature death, even after genetic disorders are taken into account (Journal of the American Medical Association).

Improving fitness appears to help men live longer following a heart attack (The National Exercise and Heart Disease Project).

Lifestyle physical activity, such as taking the stairs, gardening, and walking instead of driving, is as effective as structured gym workouts in improving fitness (Journal of the American Medical Association).

Even infrequent exercise helps postmenopausal women live longer (Journal of the American Medical Association).

Want to know where to begin? For starters, just think about opportunities to increase your physical activity when you go about your daily business. Instead of putting off the trip upstairs until you have more than one reason to go up there, go up any time an opportunity presents itself. In stores or at work, pretend the elevator doesn't exist. And why on earth wait for the "best" available parking space when you could park away from the crowds and take a few extra steps to the building? If you think you don't have time for these changes, think again. Not taking a few extra minutes now may actually shave off years from your life.

Exercise is so important for a number of reasons. For one, your body was designed to be used. Like any fine tool or instrument, it can get rusty or off-key if it just sits around, but when it's regularly tuned up, it gives you optimal performance. Fitness helps you to look and feel good. And let's face it. When you are not fit, it's near impossible to feel good about yourself.

How do you know whether or not you're fit? That depends on lots of things, such as your age, overall health, family history, exercise routines and eating habits. Granted, you can't change all of these influences, but you'll find if you work on the ones you can do something about, your overall health is bound to improve.

What is fitness?

Fitness can be described as a condition that helps us look, feel and do our best. That means being able to rely on your body to perform when you need it to, whether it be doing daily household tasks, enjoying a brisk walk on a beautiful fall day, running a race or bench pressing your own body weight. Only you can set your fitness goals. Your present fitness level, age, health, skills, interest and convenience are among the factors you should consider. If you start out slowly, you may find that a simple success spurs you on to take it to the next level.

The President's Council on Physical Fitness and Sports outlines the following five basic components to physical fitness:

Cardiorespiratory endurance - The ability to deliver oxygen and nutrients to tissues and to remove wastes throughout sustained periods of time. Long runs and swims are among the methods employed in measuring this component.

Muscular strength - The ability of a muscle to exert force for a brief period of time. Upper-body strength, for example, can be measured by various weight-lifting exercises.

Muscular endurance - The ability of a muscle, or a group of muscles, to sustain repeated contractions or to continue applying force against a fixed object. Push-ups are often used to test endurance of arm and shoulder muscles.

Flexibility - The ability to move joints and use muscles through their full range of motion. The sit-and-reach test is a good measure of flexibility of the lower back and backs of the upper legs.

Body composition - Often considered a component of fitness. It refers to the makeup of the body in terms of lean mass (muscle, bone, vital tissue and organs) and fat mass. A particular ratio of fat to lean mass is an indication of fitness, and the right types of exercise will help you decrease body fat and increase or maintain muscle mass.

Your exercise program should include something to improve each of these five basic fitness components. Each workout should begin with a warm-up and end with a cool-down. A warm-up generally consists of five to 10 minutes of low intensity movements, such as walking, slow jogging, knee lifts, arm circles or trunk rotations. A cool-down consists of a minimum of five to 10 minutes of slow walking, low-level exercise, combined with stretching. As a general rule, you should try to get moderate intensity exercise, like brisk walking, most days of the week.

Healthy Eating

2007-09-27T16:08:00.000+02:00

Healthy Eating

Good nutrition and a balanced diet will help your child grow up healthy. Whether your kid is a toddler or a teen, you can take steps to improve nutrition and encourage smart eating habits. Five of the best strategies are:

Have regular family meals.
Serve a variety of healthy foods and snacks.
Be a role model by eating healthy yourself.
Avoid battles over food.
Involve kids in the process.

But it's not easy to take these steps when everyone is juggling busy schedules and convenience food, such as fast food, is so readily available. Here are some suggestions to help you incorporate all five strategies into your routine:

Family Meals

Family meals are a comforting ritual for both parents and kids. Children like the predictability of family meals and parents get a chance to catch up with their kids. Kids who take part in regular family meals are also:

more likely to eat fruits, vegetables, and grains
less likely to snack on unhealthy foods
less likely to smoke, use marijuana, or drink alcohol

In addition, family meals offer the chance to introduce your child to new foods and find out which foods your child likes and which ones he or she doesn't.

Teens may turn up their noses at the prospect of a family meal - not surprising because they're trying to establish independence. Yet studies find that teens still want their parents' advice and counsel, so use mealtime as a chance to reconnect. Also, consider trying these strategies:

Allow your teen to invite a friend to dinner.
Involve your teen in meal planning and preparation.
Keep mealtime calm and congenial - no lectures or arguing.

What counts as a family meal? Any time you and your family eat together - whether it's takeout food or a home-cooked meal with all the trimmings. Strive for nutritious food and a time when everyone can be there. This may mean eating dinner a little later to accommodate a child who's at sports practice. It can also mean setting aside time on the weekends, such as Sunday brunch, when it may be more convenient to gather as a group.

Stocking Up on Healthy Foods

Kids, especially younger ones, will eat mostly what's available at home. That's why it's important to control the supply lines - the foods that you serve for meals and have on hand for snacks. Follow these basic guidelines:

Work fruits and vegetables into the daily routine, aiming for the goal of 5 servings a day.
Make it easy for your child to choose healthy snacks by keeping fruits and vegetables on hand and ready to eat. Other good snacks include yogurt, peanut butter and celery, or whole-grain crackers and cheese.
Serve lean meats and other good sources of protein, such as eggs and nuts.
Choose whole-grain breads and cereals so your child gets more fiber.
Limit fat intake by avoiding deep-fried foods and choosing healthier cooking methods, such as broiling, grilling, roasting, and steaming.
Limit fast food and other low-nutrient snacks, such as chips and candy. But don't completely ban favorite snacks from your home. Instead, make them "once-in-a-while" foods, so your child doesn't feel deprived.
Limit sugary drinks, such as soda and fruit-flavored drinks. Serve water and milk instead.

By drinking milk, kids also boost their intake of calcium, which is important for healthy bones. That means 800 milligrams (mg) a day for kids ages 6 to 8 and 1,300 mg a day after age 9. To reach the 1,300-mg goal, your child could have:

1 cup (237 milliliters) of milk (300 mg of calcium)
1 cup (237 milliliters) of calcium-fortified orange juice (300 mg of calcium)
2 ounces (57 grams) of cheese (300 mg of calcium)
1 cup (237 milliliters) of yogurt (315 mg of calcium)
1/2 cup (118 milliliters) of cooked white beans (120 mg of calcium)

Nutrition

2007-09-27T16:07:00.001+02:00

Chocolate Milk - a Sports Drink?

Research from Indiana University suggests that chocolate milk is as good as sports drinks for recovery after intense endurance sports. Does this mean that chocolate milk is a healthy beverage?

I asked Felicia D. Stoler, MS, RD, host of the TLC program “Honey We’re Killing the Kids” her thoughts:

My kids love chocolate milk… so as a sports drink, it’s easy to get them to drink it for post-exercise replenishment… for carbohydrates, protein, electrolytes, vitamins & minerals. I’m not surprised by the study…milk is a pretty nutrient dense food with variable fat content. Low-fat chocolate milk is great for active people after a workout because its powerful nutrient package provides energy, protein, calcium and seven other essential nutrients (including potassium, phosphorus, vitamins A, D and B12, riboflavin and niacin.) As we see with other sports beverages, people consume more if it is sweet in flavor! Chocolate milk can be quickly absorbed into the body. There is also great packaging for flavored milk which makes it a great grab‘n go snack (we always keep NESQUIK Ready to Drink in the fridge).

Chocolate Milk Cartoon Icon “Quickie” the athletic NESQUIK Bunny will be spreading the word on the importance of exercise and the health benefits of drinking chocolate-flavored milk by running in 6 races – three in NYC and three in LA from the end of September through the beginning of November. Quickie’s first race will be in NYC on Saturday, September 29th at the Fifth Avenue Mile.

I asked Ms. Stoler a couple of other questions kids, exercise and weight.

What other foods or beverages can have a similar affect on muscle recovery as chocolate milk and sports drinks?

Replenishment needs are really based upon the duration and intensity of the exercise… for exercise of under an hour, water is usually sufficient. Yogurt & cheese have a similar benefit without as much fluid (wash it down with water). Replenishment of nutrients can also come from foods one would have in a meal… there is not always a need for anything “fancy”.

What about childhood obesity? What can we do to help kids watch their weight?

Parents can lead by example… take walks together as a family, ride bicycles, swim, play sports together. Many towns have recreation departments that offer recreational sports & facilities that are low in cost to residents. Additionally, parents should be advocates for regular physical education in schools... no child should be left ON their behind! Turn off the electronics…television, computers, video games, etc. Turn on the music in your house & dance with your kids!Are there other foods that make tasty healthy snacks, are fun, and that kids of all ages love?

Can you give us some ideas for foods that make tasty healthy snacks, are fun, and that kids of all ages love?

Almost all kids love fruits, cheese, yogurts (esp the squeeze tube or drinkable varieties which are easily transportable)…even pretzels can be a good snack. Popcorn (air popped, microwave… but low fat) and whole grain crackers (a great way to sneak fiber into a kids daily intake). The 100-calorie snack packs are a great way to control portions – as long as kids only eat one or two a day!

More About Chocolate Milk

Daily Nutrition Tip

Thursday September 27, 2007 | permalink | comments (0)

Do You Need a Multivitamin Supplement?

Many experts believe that a healthy balanced diet will provide you with all of the nutrients you need. If you go to your local grocery store, pharmacy or big discount store, you will find rows of multivitamins and dietary supplements. Do you think you really need them? Is there any evidence that taking dietary supplements every day does any good?

Before you go out and buy a daily vitamin or other dietary supplements, read Do I Really Need to Take Vitamins? to learn more.

Poll: Do you take multiple-vitamin and mineral supplements?

Related Articles:

Daily Nutrition Tip

Tuesday September 25, 2007 | permalink | comments (0)

Organic Foods

Organic foods are becoming more popular due to concerns about pesticide use, synthetic fertilizer and herbicide residues in our food. Growing food organically is more work-intensive and so it is more expensive than non-organically grown food, but many people think that going organic is worth the extra price.

Not all foods that have the word organic on the label are completely free of bad stuff. If you want to buy organic foods, take some time to learn what the word organic means when you see in on a label. Read Organic Food Basics to learn more.

Poll:Do you buy organic foods?

More About Organic Foods

Daily Nutrition Tip

Sunday September 23, 2007 | permalink | comments (0)

Fruits and Vegetables for Healthy Eyes

There are very few good reasons for not eating lots of fruits and vegetables. Actually, I can't really think of any good reasons to not eat them. There is a long list of the health benefits you will experience if you eat fruits and vegetables every day.

One of those benefits is healthy vision. The antioxidants called lutein and zeaxanthin found in many fruits and vegetables will decrease your risk of suffering from the age-related eye diseases macular degeneration and cataracts.

Learn how to get more fruits and vegetables into your diet every day.

More About Nutrition and Your Eyes

Daily Nutrition Tip

Friday September 21, 2007 | permalink | comments (0)

Foods for Low Fat and Low Carb Diets

Low fat and low carb diets are two popular ways to lose and maintain a healthy weight. Both diets can be very healthy as long as you include foods that are good for you. Low fat protein sources and low starch vegetables are both healthy and delicious.

Here is my list of the top ten foods that can be included in either a low fat or a low carb diet. I've also included some links to recipes from About.com cooking sites.

Poll:Which type of diet do you think is the healthiest?

More About Diets

Daily Nutrition Tip

Tuesday September 18, 2007 | permalink | comments (0)

Healthy Salads

Although summer may be ending, the thought of eating light tasty salads still seems like a great idea. A salad with greens, vegetables, fruits and nuts is perfect before a meal, or a salad can be the meal if you make it big with lots of healthy vegetables.

Eating healthy salads will help you to control your weight, too. Want to know how to make a salad that is high in nutrition an fiber, without a lot of calories? Here is how to create a healthy salad.

Poll: What is your favorite type of salad green?

Related Articles:

Daily Nutrition Tip

Thursday September 13, 2007 | permalink | comments (2)

Nutritional Jungle

I just read an interesting book by Cathy Schmelter, R.D. The book is called Cutting Thru the Nutritional Jungle is aimed at parents of children who are overweight and undernourished – parents who are in need of basic nutrition education.

Read my review of Cutting Thru the Nutritional Jungle

More About Kids and Nutrition

Daily Nutrition Tip

Tuesday September 11, 2007 | permalink | comments (0)

Healthy and Safe Fish For Your Kids

Fish is a terrific source of omega-3 essential fatty acids and protein so that makes it the perfect brain food for kids. Unfortunately, a lot of fish and seafood is contaminated with stuff like mercury and other toxins. Not only that, but many people feel kind of clueless when it comes to cooking fish.

That doesn't mean that you need to resort to fish-sticks to feed your kids. The people at KidSafe Seafoods have lots of information about which fish are the healthiest for you and your children. They also have several ideas for cooking delicious meals with fish that your kids will love.

How do I know? Last week I had the good fortune to take my kids to a delicious seafood picnic in New York sponsored by KidSafe. My kids are the pickiest eaters I know and they just loved the different fish and seafood dishes that were served. Learn more about healthy fish and delicious recipes at KidSafe Seafoods.

Delicious Fish and Seafood

Daily Nutrition Tip

Wednesday September 5, 2007 | permalink | comments (0)

Before You Buy a Cookbook

I have to admit that I don't use cookbooks much anymore. I find most of my recipes online, or sometimes to my children's horror, I just make up the recipes as I go along.

Now and then I will dust off a couple of my old cookbooks and re-familiarize myself with some old favorite recipes. Occasionally I have the urge to buy a new cookbook. Until I see how many there are in the book store. Rows and rows of them, and it can be daunting to go through that entire selection to find the perfect cookbook. Low fat, low carb, high fiber, easy to cook, difficult to cook, baking, breakfast, one-dish, crock-pot, etc ... The list seems endless.

If this sounds familiar, you might want to read our low fat cooking guide Fiona Hayne's article on how to choose a cookbook before you head out to your book store.

Breaking The Speed Of Light

2007-09-27T15:55:00.000+02:00

Speed of light broken with basic lab kit

10:03 16 September 2002
NewScientist.com news service
Charles Choi

Electric signals can be transmitted at least four times faster than the speed of light using only basic equipment that would be found in virtually any college science department.

Scientists have sent light signals at faster-than-light speeds over the distances of a few metres for the last two decades - but only with the aid of complicated, expensive equipment. Now physicists at Middle Tennessee State University have broken that speed limit over distances of nearly 120 metres, using off-the-shelf equipment costing just $500.

Jeremy Munday and Bill Robertson made a 120-metre-long cable by alternating six- to eight-metre-long lengths of two different kinds of coaxial cable, each with a different electrical impedance. They hooked this hybrid cable up to two signal generators, one of which broadcast a fast wave, the other a slow one. The waves interfere with each other to produce electric pulses, which can be watched using an oscilloscope.

Any pulse, whether electrical, light or sound, can be imagined as a group of tiny intermingled waves. The energy of this "group pulse" rises and falls over space, with a peak in the middle. The different electrical resistances in the hybrid cable cause the waves in the pulse's rear to reflect off each other, accelerating the pulse's peak forward.

Four billion km/h

By using the oscilloscope to trace the pulse's strength and speed, the researchers confirmed they sent the signal's peak tunnelling through the cable at more than four billion kilometres per hour.

"It really is basement science," Robertson said. The apparatus is so simple that Robertson once assembled the setup from scratch in 40 minutes.

While the peak moves faster than light speed, the total energy of the pulse does not. This means Einstein's relativity is preserved, so do not expect super-fast starships or time machines anytime soon.

Signals also get weaker and more distorted the faster they go, so in theory no useful information can get transmitted at faster-than-light speeds, though Robertson hopes his students and others can now rigorously and cheaply test those ideas.

Physicist Alain Hache at the University of Moncton in Canada adds that it may be possible to use this reflection technique to boost electrical signal speeds in computers and telecommunications grids by more than 50 per cent.

Electrical signals usually travel at about two-thirds of light speed in wires. Hache says it may be possible to send unsable electrical signals to near light speed.

The Cloack Of Invisibility

2007-09-27T15:45:00.002+02:00

How Invisibility Cloaks Work

by William Harris

Inside This Article

Introduction to How Invisibility Cloaks Work

Altered Reality

More Invisibility Cloak Components

The Complete System

Head-mounted Displays

Real-World Applications

Lots More Information

See all Engineering articles

If you're a fan of Harry Potter, then you're quite familiar with the concept of an invisibility cloak. In his first year at Hogwarts Academy, Harry receives an invisibility cloak that used to belong to his father. As its name suggests, the invisibility cloak renders Harry invisible when he slips beneath the shining, silvery cloth.

Photo courtesy ©Tachi Laboratory, the University of Tokyo
Optical-camouflage technology developed at the University of Tokyo

This seems perfectly believable when you're reading about a fictional world filled with witches, wizards and centuries-old magic; but in the real world, such a garment would be impossible, right? Not so fast. With optical-camouflage technology developed by scientists at the University of Tokyo, the invisibility cloak is already a reality.

Optical camouflage delivers a similar experience to Harry Potter's invisibility cloak, but using it requires a slightly more complicated arrangement. First, the person who wants to be invisible (let's call her Person A) dons a garment that resembles a hooded raincoat. The garment is made of a special material that we'll examine more closely in a moment. Next, an observer (Person B) stands before Person A at a specific location. At that location, instead of seeing Person A wearing a hooded raincoat, Person B sees right through the cloak, making Person A appear to be invisible. The photograph on the right below shows you what Person B would see. If Person B were viewing from a slightly different location, he would simply see Person A wearing a silver garment (left photograph below).

Photo courtesy ©Tachi Laboratory, the University of Tokyo

Still, despite its limitations, this is a cool piece of technology. Not only that, but it's also a technology that's been around for a while.

Altered Reality

Optical camouflage doesn't work by way of magic. It works by taking advantage of something called augmented-reality technology -- a type of technology that was first pioneered in the 1960s by Ivan Sutherland and his students at Harvard University and the University of Utah. You can read more about augmented reality in How Augmented Reality Will Work, but a quick recap will be helpful here.

Augmented-reality systems add computer-generated information to a user's sensory perceptions. Imagine, for example, that you're walking down a city street. As you gaze at sites along the way, additional information appears to enhance and enrich your normal view. Perhaps it's the day's specials at a restaurant or the show times at a theater or the bus schedule at the station. What's critical to understand here is that augmented reality is not the same as virtual reality. While virtual reality aims to replace the world, augmented reality merely tries to supplement it with additional, helpful content.

Augmented-reality displays overlay computer-generated graphics onto the real world.

Most augmented-reality systems require that users look through a special viewing apparatus to see a real-world scene enhanced with synthesized graphics. They also require a powerful computer. Optical camouflage requires these things, as well, but it also requires several other components. Here's everything needed to make a person appear invisible:

A garment made from highly reflective material
A video camera
A computer
A projector
A special, half-silvered mirror called a combiner

Let's look at each of these components in greater detail.

The Cloak
The cloak that enables optical camouflage to work is made from a special material known as retro-reflective material.

Photo courtesy ©Tachi Laboratory, the University of Tokyo
Invisibility cloak

A retro-reflective material is covered with thousands and thousands of small beads. When light strikes one of these beads, the light rays bounce back exactly in the same direction from which they came.

To understand why this is unique, look at how light reflects off of other types of surfaces. A rough surface creates a diffused reflection because the incident (incoming) light rays get scattered in many different directions. A perfectly smooth surface, like that of a mirror, creates what is known as a specular reflection -- a reflection in which incident light rays and reflected light rays form the exact same angle with the mirror surface. In retro-reflection, the glass beads act like prisms, bending the light rays by a process known as refraction. This causes the reflected light rays to travel back along the same path as the incident light rays. The result: An observer situated at the light source receives more of the reflected light and therefore sees a brighter reflection.

Retro-reflective materials are actually quite common. Traffic signs, road markers and bicycle reflectors all take advantage of retro-reflection to be more visible to people driving at night. Movie screens used in most modern commercial theaters also take advantage of this material because it allows for high brilliance under dark conditions. In optical camouflage, the use of retro-reflective material is critical because it can be seen from far away and outside in bright sunlight -- two requirements for the illusion of invisibility.

Inside This Article

Introduction to How Invisibility Cloaks Work

Altered Reality

More Invisibility Cloak Components

The Complete System

Head-mounted Displays

Real-World Applications

Lots More Information

See all Engineering articles

More Invisibility Cloak Components

Video Camera

Photo courtesy ©Tachi Laboratory, the University of Tokyo

The retro-reflective garment doesn't actually make a person invisible -- in fact, it's perfectly opaque. What the garment does is create an illusion of invisibility by acting like a movie screen onto which an image from the background is projected. Capturing the background image requires a video camera, which sits behind the person wearing the cloak. The video from the camera must be in a digital format so it can be sent to a computer for processing.

Computer
All augmented-reality systems rely on powerful computers to synthesize graphics and then superimpose them on a real-world image. For optical camouflage to work, the hardware/software combo must take the captured image from the video camera, calculate the appropriate perspective to simulate reality and transform the captured image into the image that will be projected onto the retro-reflective material.

The Projector

Photo courtesy ©Tachi Laboratory, the University of Tokyo

The modified image produced by the computer must be shone onto the garment, which acts like a movie screen. A projector accomplishes this task by shining a light beam through an opening controlled by a device called an iris diaphragm. An iris diaphragm is made of thin, opaque plates, and turning a ring changes the diameter of the central opening. For optical camouflage to work properly, this opening must be the size of a pinhole. Why? This ensures a larger depth of field so that the screen (in this case the cloak) can be located any distance from the projector.

The Combiner
The system requires a special mirror to both reflect the projected image toward the cloak and to let light rays bouncing off the cloak return to the user's eye. This special mirror is called a beam splitter, or a combiner -- a half-silvered mirror that both reflects light (the silvered half) and transmits light (the transparent half). If properly positioned in front of the user's eye, the combiner allows the user to perceive both the image enhanced by the computer and light from the surrounding world. This is critical because the computer-generated image and the real-world scene must be fully integrated for the illusion of invisibility to seem realistic. The user has to look through a peephole in this mirror to see the augmented reality.

The Complete System

Now let's put all of these components together to see how the invisibility cloak appears to make a person transparent. The diagram below shows the typical arrangement of all of the various devices and pieces of equipment.

Once a person puts on the cloak made with the retro-reflective material, here's the sequence of events:

A digital video camera captures the scene behind the person wearing the cloak.
The computer processes the captured image and makes the calculations necessary to adjust the still image or video so it will look realistic when it is projected.
The projector receives the enhanced image from the computer and shines the image through a pinhole-sized opening onto the combiner.
The silvered half of the mirror, which is completely reflective, bounces the projected image toward the person wearing the cloak.
The cloak acts like a movie screen, reflecting light directly back to the source, which in this case is the mirror.
Light rays bouncing off of the cloak pass through the transparent part of the mirror and fall on the user's eyes. Remember that the light rays bouncing off of the cloak contain the image of the scene that exists behind the person wearing the cloak.

The person wearing the cloak appears invisible because the background scene is being displayed onto the retro-reflective material. At the same time, light rays from the rest of the world are allowed reach the user's eye, making it seem as if an invisible person exists in an otherwise normal-looking world.

The Speed Of Light

2007-09-27T15:45:00.001+02:00

“Lightspeed” redirects here. For other uses, see Lightspeed (disambiguation).

The speed of light in vacuum is an important physical constant denoted by the letter c for constant or the Latin word celeritas meaning "swiftness".^[1] It is the speed of all electromagnetic radiation, including visible light, in a vacuum. More generally, it is the speed of anything having zero rest mass.

A line showing the speed of light on a scale model of Earth and the Moon, about 1.2 seconds.

In metric units, c is exactly 299,792,458 metres per second (1,079,252,848.8 km/h).^[2] The fundamental SI unit of length, the metre, has been defined since October 21, 1983, as the distance light travels in a vacuum in 1/299,792,458 of a second; any increase in the precision of the measurement of the speed of light would refine the definition of the metre, but not alter the numerical value of c. The approximate value of 3×10⁸ m/s is commonly used in rough estimates. In imperial units, the speed of light is about 670,616,629.2 miles per hour or 983,571,056 feet per second, which is about 186,282.397 miles per second, or roughly one foot per nanosecond.

The speed of light when it passes through a transparent or translucent material medium, like glass or air, is slower than its speed in a vacuum. The ratio of c to the observed phase velocity is called the refractive index of the medium. General relativity explains how a gravitational potential can affect the apparent speed of distant light in a vacuum, but locally light in a vacuum always passes an observer at a rate of c.

[edit] Overview

One consequence of the laws of electromagnetism (such as Maxwell's equations) is that the speed c of electromagnetic radiation does not depend on the velocity of the object emitting the radiation; thus for instance the light emitted from a rapidly moving light source would travel at the same speed as the light coming from a stationary light source (although the colour, frequency, energy, and momentum of the light will be shifted, which is called the relativistic Doppler effect). If one combines this observation with the principle of relativity, one concludes that all observers will measure the speed of light in vacuum as being the same, regardless of the reference frame of the observer or the velocity of the object emitting the light. Because of this fact, one can view c as a fundamental physical constant. This logic is the basis of the theory of special relativity.^[3]

Observers traveling at large velocities will find that distances and times are distorted in accordance with the Lorentz transforms; however, the transformations distort times and distances in such a way that the speed of light remains constant. A light sensor traveling near the speed of light would also find that colours of lights ahead were shifted toward the violet end of the spectrum and of those behind were redshifted, so that the Lorentz transformations and classical explanations of frequency shifting are in harmony.

If information could travel faster than c in one reference frame, causality would be violated: in some other reference frames, the information would be received before it had been sent, so the 'effect' could be observed before the 'cause'. Due to special relativity's time dilation, the ratio between an external observer's perceived time and the time perceived by an observer moving closer and closer to the speed of light approaches zero. If something could move faster than light, this ratio would not be a real number. Such a violation of causality has never been recorded.

A light cone defines locations that are in causal contact and those that are not.

To put it another way, information propagates to and from a point from regions defined by a light cone. The interval AB in the diagram to the right is 'time-like' (that is, there is a frame of reference in which event A and event B occur at the same location in space, separated only by their occurring at different times, and if A precedes B in that frame then A precedes B in all frames: there is no frame of reference in which event A and event B occur simultaneously). Thus, it is hypothetically possible for matter (or information) to travel from A to B, so there can be a causal relationship (with A the 'cause' and B the 'effect').

On the other hand, the interval AC in the diagram to the right is 'space-like' (that is, there is a frame of reference in which event A and event C occur simultaneously, separated only in space; (see simultaneity). However, there are also frames in which A precedes C (as shown) or in which C precedes A. Barring some way of traveling faster than light, it is not possible for any matter (or information) to travel from A to C or from C to A. Thus there is no causal connection between A and C.

According to the currently prevailing definition, adopted in 1983, the speed of light is exactly 299,792,458 metres per second (approximately 3×10⁸ metres per second, or about thirty centimetres (one foot) per nanosecond). The value of $c$ defines the permittivity of free space ( $ε 0$ ) in SI units as:

The magnetic constant $μ 0$ is not dependent on $c$ and is defined in SI units as:

These constants appear in Maxwell's equations, which describe electromagnetism, and are related by:

Astronomical distances are sometimes measured in light years (the distance that light would travel in one year, roughly 9.46×10¹² kilometres or about 5.88×10¹² miles). Because light travels at a large but finite speed, it takes time for light to cover large distances. Thus, when we see the light of very distant objects in the universe, we are actually seeing light emitted from them a long time ago: we see them literally as they were in the distant past.

[edit] Communications and GPS

The speed of light is of relevance to communications. For example, given the equatorial circumference of the Earth is 40100 km and c = 3.0E+5 km/s, the theoretical shortest amount of time for a piece of information to travel half the globe along the surface is 0.0668 s.

The actual transit time is longer, in part because the speed of light is slower by about 30% in an optical fiber and straight lines rarely occur in global communications situations, but also because delays are created when the signal passes through an electronic switch or signal regenerator. A typical time as of 2004 for a U.S. to Australia or Japan computer-to-computer ping is 0.18 s. The speed of light additionally affects wireless communications design.

Another consequence of the finite speed of light is that communications with spacecraft are not instantaneous, and the gap becomes more noticeable as distances increase. This delay was significant for communications between Houston ground control and Apollo 8 when it became the first spacecraft to orbit the Moon: For every question, Houston had to wait nearly 3 seconds for the answer to arrive, even when the astronauts replied immediately.

This effect forms the basis of the Global Positioning System (GPS), and similar navigation systems. One's position can be determined by means of the delays in radio signals received from a number of satellites, each carrying a very accurate atomic clock, and very carefully synchronized. It is remarkable that, to work properly, this method requires that (among many other effects) the relative motion of satellite and receiver be taken into effect, which was how (on an interplanetary scale) the finite speed of light was originally discovered (see the following section).

Similarly, instantaneous remote control of interplanetary spacecraft is impossible because it takes time for the Earth-based controllers to receive information from the craft, and an equal time for instructions to be received by the craft. It can take hours for controllers to become aware of a problem, respond with instructions, and have the spacecraft receive the instructions.

The speed of light can also be of concern on very short distances. In supercomputers, the speed of light imposes a limit on how quickly data can be sent between processors. If a processor operates at 1 GHz, a signal can only travel a maximum of 300 mm in a single cycle. Processors must therefore be placed close to each other to minimize communication latencies. If clock frequencies continue to increase, the speed of light will eventually become a limiting factor for the internal design of single chips.

[edit] Physics

[edit] Constant velocity from all inertial reference frames

Most individuals are accustomed to the addition rule of velocities: if two cars approach each other from opposite directions, each traveling at a speed of 50 km/h, relative to the road surface, one expects that each car will perceive the other as approaching at a combined speed of 50 + 50 = 100 km/h to a very high degree of accuracy.

However, at velocities at or approaching the speed of light, this rule does not apply. Two spaceships approaching each other, each traveling at 90% the speed of light relative to some third observer between them, do not perceive each other as approaching at 90% + 90% = 180% the speed of light; instead they each perceive the other as approaching at slightly less than 99.5% the speed of light. This last result is given by the Einstein velocity addition formula:

where $v$ and $w$ are the (positive) speeds of the spaceships as observed by the third observer, and $u$ is the speed of either space ship as observed by the other.^[4] From this, we can see how this reduces to $u = v + w$ for sufficiently small values of $v$ and $w$ (such as those typically encountered in common daily experiences), as the term $v w / c 2$ approaches zero, reducing the denominator to 1.

If one of the velocities for the above formula (or both) are c, the final result is c, as is expected if the speed of light is the same in all reference frames. Another important result comes from this formula always returning a value which is less than c whenever v and w are less than c: This shows that no acceleration in any frame of reference can cause you to exceed the speed of light with respect to another observer. Thus c acts as a speed limit for all objects with respect to all other objects in special relativity.

[edit] Luminiferous aether (discredited)

Interference pattern produced with a Michelson interferometer

Before the advent of special relativity, it was believed that light travels through a medium called the luminiferous aether. Maxwell’s equations predict a given speed of light, in much the same way as is the speed of sound in air. The speed of sound in air is actually relative to the movement of the air itself, and the speed of sound in air with respect to an observer may be changed if the observer is moving with respect to the air (or vice versa). The speed of light was believed to be relative to a medium of transmission for light that acted as air does for the transmission of sound—the luminiferous aether.

The Michelson–Morley experiment, arguably the most famous and useful failed experiment in the history of physics, was designed to detect the motion of the Earth through the luminiferous aether. It could not find any trace of this kind of motion, suggesting, as a result, that it is impossible to detect one's presumed absolute motion, that is, motion with respect to the hypothesized luminiferous aether. The Michelson–Morley experiment said little about the speed of light relative to the light’s source and observer’s velocity, as both the source and observer in this experiment were traveling at the same velocity together in space.

[edit] Interaction with transparent materials

The refractive index of a material indicates how much slower the speed of light is in that medium than in a vacuum. The slower speed of light in materials can cause refraction, as demonstrated by this prism (in the case of a prism splitting white light into a spectrum of colours, the refraction is known as dispersion).

In passing through materials, the observed speed of light can differ from c. The ratio of c to the phase velocity of light in the material is called the refractive index. This apparent contradiction to the universality of the constant c is a consequence of sloppy (but universally practiced) nomenclature: what is referred to as light in a medium is really a light-like hybrid of electromagnetic waves and mechanical oscillations of charged or magnetic particles such as electrons or ions, whereas light in the strict sense is a pure electromagnetic wave (see further discussion below). The speed of light in air is only slightly less than $c$ . Denser media, such as water and glass, can slow light much more, to fractions such as ¾ and ⅔ of c. Through diamond, light is much slower—only about 124,000 kilometres per second, less than ½ of c.^[5] This reduction in speed is also responsible for bending of light at an interface between two materials with different indices, a phenomenon known as refraction.

Since the speed of light in a material depends on the refractive index, and the refractive index depends on the frequency of the light, light at different frequencies travels at different speeds through the same material. This can cause distortion of electromagnetic waves that consist of multiple frequencies, an effect called dispersion.

Note that the speed of light referred to is the observed or measured speed in some medium and not the true speed of light (as observed in vacuum). It may be noted, that once the light has emerged from the medium it changes back to its original speed and this is without gaining any energy. This can mean only one thing—that the light's speed itself was never altered in the first place.

It is sometimes claimed that light is slowed on its passage through a block of media by being absorbed and re-emitted by the atoms, only traveling at full speed through the vacuum between atoms. This explanation is incorrect and runs into problems if you try to use it to explain the details of refraction beyond the simple slowing of the signal.

Classically, considering electromagnetic radiation to be like a wave, the charges of each atom (primarily the electrons) interfere with the electric and magnetic fields of the radiation, slowing its progress.

The full quantum-mechanical explanation is essentially the same, but has to cope with the discrete particle nature (see Photons in matter): The E-field creates phonons in the media, and the photons mix with the phonons. The resulting mixture, called a polariton, travels with a speed different from light.

[edit] Accelerated frames of reference and general relativity

Although it is constant in inertial frames of reference in special relativity, the speed of light can vary based on its position for accelerated frames of reference in special relativity and in general relativity. Before heading into this discussion, it must first be noted that in all cases the speed of light locally remains c in these cases. So when an observer measures the speed of light at his own position, the constancy of its speed holds. The issue arises at positions distant from the observer in these situations.

The cause of this change is gravitational time dilation. As clocks at lower gravitational potentials tick slower, a beam of light will take longer to move along a rod at a lower gravitational potential than it would take to move along an identical rod at ones own potential. This light is considered to be moving more slowly at lower potentials. This slowdown becomes extreme as the light approaches the event horizon of a black hole, where both time and light will appear to stop. Similarly, light will appear to go faster at higher gravitational potentials.

In general relativity, the curvature of spacetime can also affect the number of rods between certain positions. This will add another factor to magnitude of the apparent speed change.

[edit] "Faster-than-light" observations and experiments

Main article: Faster-than-light

The blue glow in this "swimming pool" nuclear reactor is Cherenkov radiation, emitted as a result of electrons traveling faster than the speed of light in water.

It has long been known theoretically that it is possible for the "group velocity" of light to exceed c.^[6] One recent experiment made the group velocity of laser beams travel for extremely short distances through caesium atoms at 300 times c. In 2002, at the Université de Moncton, physicist Alain Haché made history by sending pulses at a group velocity of three times light speed over a long distance for the first time, transmitted through a 120-metre cable made from a coaxial photonic crystal.^[7] However, it is not possible to use this technique to transfer information faster than c: the velocity of information transfer depends on the front velocity (the speed at which the first rise of a pulse above zero moves forward) and the product of the group velocity and the front velocity is equal to the square of the normal speed of light in the material.

Exceeding the group velocity of light in this manner is comparable to exceeding the speed of sound by arranging people distantly spaced in a line, and asking them all to shout "I'm here!", one after another with short intervals, each one timing it by looking at their own wristwatch so they don't have to wait until they hear the previous person shouting. Another example can be seen when watching ocean waves washing up on shore. With a narrow enough angle between the wave and the shoreline, the breakers travel along the waves' length much faster than the waves' movement inland.

The speed of light may also appear to be exceeded in some phenomena involving evanescent waves, such as tunnelling. Experiments indicate that the phase velocity and the group velocity of evanescent waves may exceed c; however, it would appear that the front velocity does not exceed c, so, again, it is not possible for information to be transmitted faster than c.

In quantum mechanics, certain quantum effects may be transmitted at speeds greater than c (indeed, action at a distance has long been perceived by some as a problem with quantum mechanics: see EPR paradox, interpretations of quantum mechanics). For example, the quantum states of two particles can be entangled, so the state of one particle fixes the state of the other particle (say, one must have spin +½ and the other must have spin −½). Until the particles are observed, they exist in a superposition of two quantum states, (+½, −½) and (−½, +½). If the particles are separated and one of them is observed to determine its quantum state then the quantum state of the second particle is determined automatically. If, as in some interpretations of quantum mechanics, one presumes that the information about the quantum state is local to one particle, then one must conclude that second particle takes up its quantum state instantaneously, as soon as the first observation is carried out. However, it is impossible to control which quantum state the first particle will take on when it is observed, so no information can be transmitted in this manner. The laws of physics also appear to prevent information from being transferred through more clever ways and this has led to the formulation of rules such as the no-cloning theorem and the no-communication theorem.

So-called superluminal motion is also seen in certain astronomical objects, such as the jets of radio galaxies and quasars. However, these jets are not actually moving at speeds in excess of the speed of light: the apparent superluminal motion is a projection effect caused by objects moving near the speed of light and at a small angle to the line of sight.

Although it may sound paradoxical, it is possible for shock waves to be formed with electromagnetic radiation. As a charged particle travels through an insulating medium, it disrupts the local electromagnetic field in the medium. Electrons in the atoms of the medium will be displaced and polarised by the passing field of the charged particle, and photons are emitted as the electrons in the medium restore themselves to equilibrium after the disruption has passed. (In a conductor, the equilibrium can be restored without emitting a photon.) In normal circumstances, these photons destructively interfere with each other and no radiation is detected. However, if the disruption travels faster than the photons themselves travel, as when a charged particle exceeds the speed of light in that medium, the photons constructively interfere and intensify the observed radiation. The result (analogous to a sonic boom) is known as Cherenkov radiation.

The ability to communicate or travel faster-than-light is a popular topic in science fiction. Particles that travel faster than light, dubbed tachyons, have been proposed by particle physicists but have yet to be observed, and would potentially violate causality if they were.

Some physicists, notably João Magueijo and John Moffat, have proposed that in the past light traveled much faster than the current speed of light. This theory is called variable speed of light (VSL) and its supporters claim that it has the ability to explain many cosmological puzzles better than its rival, the inflation model of the universe. However, it has not gained wide acceptance.

[edit] "Slow light" experiments

Main article: Slow light

Refractive phenomena, such as this rainbow, are due to the slower speed of light in a medium (water, in this case).

Light traveling through a medium other than a vacuum travels below $c$ as a result of the time lag between the polarization response of the medium and the incident light. However, certain materials have an exceptionally high group index and a correspondingly low group velocity. In 1999, a team of scientists led by Lene Hau were able to slow the speed of a light pulse to about 17 metres per second;^[8] in 2001, they were able to momentarily stop a beam.^[9]

In 2003, Mikhail Lukin, with scientists at Harvard University and the Lebedev Institute in Moscow, succeeded in completely halting light by directing it into a bec (Bose–Einstein condensate) of the element rubidium, the atoms of which, in Lukin's words, behaved "like tiny mirrors" due to an interference pattern in two "control" beams.^[10]

[edit] History

Until relatively recent times, the speed of light was largely a matter of conjecture. Empedocles maintained that light was something in motion, and therefore there had to be some time elapsed in traveling. Aristotle said that, on the contrary, "light is due to the presence of something, but it is not a movement". Furthermore, if light had a finite speed, it would have to be very great; Aristotle asserted "the strain upon our powers of belief is too great" to believe this.

One of the ancient theories of vision was that light was emitted from the eye, instead of entering the eye from another source. Using this theory, Heron of Alexandria advanced the argument that the speed of light must be infinite, since distant objects such as stars appear immediately upon opening the eyes.

[edit] Medieval and early modern theories

Early Muslim philosophers initially agreed with Aristotle's view that light has an infinite speed. In the 11th century, however, Muslim scientists realized that light has a finite speed. The Iraqi Arab scientist Ibn al-Haytham (Alhacen), the father of optics, using an early experimental scientific method in his Book of Optics, discovered that light has a finite speed. Some of his contemporaries, notably the Persian scientists Avicenna and al-Biruni, also agreed with Alhacen that light has a finite speed. Avicenna "observed that if the perception of light is due to the emission of some sort of particles by a luminous source, the speed of light must be finite."^[11] Al-Biruni further discovered that the speed of light is much faster than the speed of sound.^[12]

The 14th century Indian scholar Sayana wrote in a comment on verse Rigveda 1.50.4 (1700–1100 BCE—the early Vedic period): "Thus it is remembered: [O Sun] you who traverse 2202 yojanas [ca. 14,000 to 30,000 km] in half a nimesa [ca. 0.1 to 0.2 s]", corresponding to between 65,000 and 300,000 km/s, for high values of yojana and low values of nimesa consistent with the actual speed of light.^[13]

Johannes Kepler believed that the speed of light is infinite since empty space presents no obstacle to it. Francis Bacon argued that the speed of light is not necessarily infinite, since something can travel too fast to be perceived. René Descartes argued that if the speed of light were finite, the Sun, Earth, and Moon would be noticeably out of alignment during a lunar eclipse. Since such misalignment had not been observed, Descartes concluded the speed of light is infinite. In fact, Descartes was convinced that if the speed of light was finite, his whole system of philosophy would be demolished.^[14]

[edit] Measurement of the speed of light

[edit] Early attempts

Isaac Beeckman proposed an experiment (1629) in which a person would observe the flash of a cannon reflecting off a mirror about one mile away. Galileo proposed an experiment (1638), with an apparent claim to having performed it some years earlier, to measure the speed of light by observing the delay between uncovering a lantern and its perception some distance away. This experiment was carried out by the Accademia del Cimento of Florence in 1667, with the lanterns separated by about one mile. No delay was observed. Robert Hooke explained the negative results as Galileo had: by pointing out that such observations did not establish the infinite speed of light, but only that the speed must be very great. Descartes criticised this experiment as superfluous, in that the observation of eclipses, which had more power to detect a finite speed, gave a negative result.

Rømer's observations of the occultations of Io from Earth.

[edit] Astronomical techniques

The first quantitative estimate of the speed of light was made in 1676 by Ole Rømer, who was studying the motions of Jupiter's moon, Io, with a telescope. It is possible to time the orbital revolution of Io because it enters and exits Jupiter's shadow at regular intervals (at C or D). Rømer observed that Io revolved around Jupiter once every 42.5 hours when Earth was closest to Jupiter (at H). He also observed that, as Earth and Jupiter moved apart (as from L to K), Io's exit from the shadow would begin progressively later than predicted. It was clear that these exit "signals" took longer to reach Earth, as Earth and Jupiter moved further apart. This was as a result of the extra time it took for light to cross the extra distance between the planets, time which had accumulated in the interval between one signal and the next. The opposite is the case when they are approaching (as from F to G). On the basis of his observations, Rømer estimated that it would take light 22 minutes to cross the diameter of the orbit of the Earth (that is, twice the astronomical unit); the modern estimate is closer to 16 minutes and 40 seconds.

Around the same time, the astronomical unit was estimated to be about 140 million kilometres. The astronomical unit and Rømer's time estimate were combined by Christiaan Huygens, who estimated the speed of light to be 1000 Earth diameters per minute. This is about 220,000 kilometres per second (136,000 miles per second), 26 per cent lower than the currently accepted value, but still very much faster than any physical phenomenon then known.

Isaac Newton also accepted the finite speed. In his 1704 book "Opticks" he, in fact, reports the value of 16.6 Earth diameters per second (210,000 kilometres per second, 30% less than the actual value), which it seems he inferred for himself (whether from Rømer's data, or otherwise, is not known). The same effect was subsequently observed by Rømer for a "spot" rotating with the surface of Jupiter. And later observations also showed the effect with the three other Galilean moons, where it was more difficult to observe, thus laying to rest some further objections that had been raised.

Even if, by these observations, the finite speed of light may not have been established to everyone's satisfaction (notably Jean-Dominique Cassini's), after the observations of James Bradley (1728), the hypothesis of infinite speed was considered discredited. Bradley deduced that starlight falling on the Earth should appear to come from a slight angle, which could be calculated by comparing the speed of the Earth in its orbit to the speed of light. This "aberration of light", as it is called, was observed to be about 1/200 of a degree. Bradley calculated the speed of light as about 298,000 kilometres per second (185,000 miles per second). This is only slightly less than the currently accepted value. The aberration effect has been studied extensively over the succeeding centuries, notably by Friedrich Georg Wilhelm Struve and Magnus Nyren.

Diagram of the Fizeau-Foucault apparatus.

[edit] Earth-bound techniques

The first successful measurement of the speed of light using an earthbound apparatus was carried out by Hippolyte Fizeau in 1849. (This measures the speed of light in air, which is slower than the speed of light in vacuum by a factor of the refractive index of air, about 1.0003.) Fizeau's experiment was conceptually similar to those proposed by Beeckman and Galileo. A beam of light was directed at a mirror several thousand metres away. On the way from the source to the mirror, the beam passed through a rotating cog wheel. At a certain rate of rotation, the beam could pass through one gap on the way out and another on the way back. But at slightly higher or lower rates, the beam would strike a tooth and not pass through the wheel. Knowing the distance to the mirror, the number of teeth on the wheel, and the rate of rotation, the speed of light could be calculated. Fizeau reported the speed of light as 313,000 kilometres per second. Fizeau's method was later refined by Marie Alfred Cornu (1872) and Joseph Perrotin (1900).

Leon Foucault improved on Fizeau's method by replacing the cogwheel with a rotating mirror. Foucault's estimate, published in 1862, was 298,000 kilometres per second. Foucault's method was also used by Simon Newcomb and Albert A. Michelson. Michelson began his lengthy career by replicating and improving on Foucault's method.

In 1926, Michelson used a rotating prism to measure the time it took light to make a round trip from Mount Wilson to Mount San Antonio in California. The precise measurements yielded a speed of 186,285 miles per second (299,796 kilometres per second).

[edit] Laboratory-based methods

During World War II, the development of the cavity resonance wavemeter for use in radar, together with precision timing methods, opened the way to laboratory-based measurements of the speed of light. In 1946, Louis Essen in collaboration with A.C. Gordon-Smith used a microwave cavity of precisely known dimensions to establish the frequency for a variety of normal modes of microwaves—which, in common with all electromagnetic radiation, travels at the speed of light in vacuum. As the wavelength of the modes was known from the geometry of the cavity and from electromagnetic theory, knowledge of the associated frequencies enabled a calculation of the speed of light. Their result, 299,792±3 km/s, was substantially greater than those found by optical techniques, and prompted much controversy. However, by 1950 repeated measurements by Essen established a result of 299,792.5±1 km/s; this became the value adopted by the 12th General Assembly of the Radio-Scientific Union in 1957. Most subsequent measurements have been consistent with this value.

[edit] Speed of light set by definition

In 1983, the 17th Conférence Générale des Poids et Mesures adopted a standard value, 299,792,458 m/s for the speed of light. This in turn defines the length of a meter in terms of the speed of light, so that further refinements in the current experimental value of the speed of light actually would just refine the definition of a meter.

[edit] Relativity

From the work of James Clerk Maxwell, it was known that the speed of electromagnetic radiation was a constant defined by the electromagnetic properties of the vacuum (permittivity and permeability).

A schematic representation of a Michelson interferometer, as used for the Michelson-Morley experiment.

In 1887, the physicists Albert Michelson and Edward Morley performed the influential Michelson-Morley experiment to measure the speed of light relative to the motion of the earth, the goal being to measure the velocity of the Earth through the "luminiferous aether", the medium that was then thought to be necessary for the transmission of light. As shown in the diagram of a Michelson interferometer, a half-silvered mirror was used to split a beam of monochromatic light into two beams traveling at right angles to one another. After leaving the splitter, each beam was reflected back and forth between mirrors several times (the same number for each beam to give a long but equal path length; the actual Michelson-Morley experiment used more mirrors than shown) then recombined to produce a pattern of constructive and destructive interference. Any slight change in speed of light along each arm of the interferometer (because the apparatus was moving with the Earth through the proposed "aether") would change the amount of time that the beam spent in transit, which would then be observed as a change in the pattern of interference. In the event, the experiment gave a null result.

Ernst Mach was among the first physicists to suggest that the experiment actually amounted to a disproof of the aether theory. Developments in theoretical physics had already begun to provide an alternative theory, Fitzgerald-Lorentz contraction, which explained the null result of the experiment.

It is uncertain whether Albert Einstein knew the results of the Michelson-Morley experiment, but the null result of the experiment greatly assisted the acceptance of his theory of relativity. Einstein's theory did not require an aether and was entirely consistent with the null result of the experiment: the aether did not exist and the speed of light was the same in each direction. The constant speed of light is one of the fundamental Postulates (together with causality and the equivalence of inertial frames) of special relativity.

[edit] See also

Wikinews has related news:

Two German scientists claim to have broken the speed of light

[edit] References

[edit] Footnotes

^ Why is c the symbol for the speed of light?. Retrieved on 2007-06-05.
^ CODATA. Speed of light in vacuum. 2006 CODATA recommended values. NIST. Retrieved on 2007-08-08.
^ It is worth noting that it is the constant speed c, rather than light itself, that is fundamental to special relativity; thus if light is somehow manipulated to travel at less than c, this manipulation will not directly affect the theory of special relativity.
^ Francis Weston Sears, Introduction to the Theory of Relativity, p. 24, footnote:

Except in giving a name to [this equation], the term "velocity" is used in this book to mean the speed and direction of motion. Velocity is a vector quantity, whereas speed refers only to the magnitude of the velocity. Since we have restricted motion to a single dimension (along the x-axis), we have not needed to introduce the concept of velocity here.
^ Refraction, Snell's law, and total internal reflection. Boston University Physics. Retrieved on 2007-01-24.
^ Egan, Greg (2000-08-17). Applets Gallery / Subluminal. Retrieved on 2007-02-06.
References LJ Wang; A Kuzmich & A Dogariu (2000-07-20). "Gain-assisted superluminal light propagation". Nature (406): p277.
^ Electrical pulses break light speed record, physicsweb, 22 January 2002; see also A Haché and L Poirier (2002), Appl. Phys. Lett. v.80 p.518.
^ L.V. Hau, S.E. Harris, Z. Dutton, and C.H. Behroozi (1999-02-18). "Light speed reduction to 17 metres per second in an ultracold atomic gas" (HTML). Nature 397: 594–598.
^ C. Liu, Z. Dutton, C.H. Behroozi, and L.V. Hau (2001-01-25). "Observation of coherent optical information storage in an atomic medium using halted light pulses" (PDF). Nature 409: 490–493.
^ M. Bajcsy1, A.S. Zibrov, and M.D. Lukin (2003-12-11). "Stationary pulses of light in an atomic medium". Nature 426: 638–641.
^ George Sarton, Introduction to the History of Science, Vol. 1, p. 710.
^ O'Connor, John J; Edmund F. Robertson "Al-Biruni". MacTutor History of Mathematics archive.
^ Subhash Kak. Light or Coincidence. IndiaStar: A Literary-Art Magazine. Retrieved on 2007-01-17.; Bengali Calendar
^ Historical Background, footnote 5. Statistics and Actuarial Science, University of Waterloo. Retrieved on 2007-08-03.

[edit] Historical references

Ole Rømer. "Démonstration touchant le mouvement de la lumière", Journal des sçavans, 7 Décembre 1676, pp. 223–236. Translated as "A Demonstration concerning the Motion of Light", Philosophical Transactions of the Royal Society no. 136, pp. 893–894; June 25, 1677. (Rømer's 1676 paper, in English and French, as bitmap images, and in French as plain text)
Edmund Halley. "Monsieur Cassini, his New and Exact Tables for the Eclipses of the First Satellite of Jupiter, reduced to the Julian Stile and Meridian of London", Philosophical Transactions XVIII, No. 214, pp 237–256, Nov.–Dec., 1694.
H.L. Fizeau. "Sur une expérience relative à la vitesse de propogation de la lumière", Comptes Rendus 29, 90–92, 132, 1849.
J.L. Foucault. "Détermination expérimentale de la vitesse de la lumière: parallaxe du Soleil", Comptes Rendus 55, 501–503, 792–796, 1862.
A.A. Michelson. "Experimental Determination of the Velocity of Light", Proceedings of the American Association for the Advancement of Science 27, 71–77, 1878. (Project Gutenberg Etext version)
Simon Newcomb. "The Velocity of Light", Nature, pp 29–32, May 13, 1886.
Joseph Perrotin. "Sur la vitesse de la lumière", Comptes Rendus 131, 731–734, 1900.
A.A. Michelson, F.G. Pease, and F. Pearson. "Measurement Of The Velocity Of Light In A Partial Vacuum", Astrophysical Journal 82, 26–61, 1935.

[edit] Modern references

Léon Brillouin. Wave propagation and group velocity. Academic Press Inc., 1960.
John David Jackson. Classical electrodynamics. John Wiley & Sons, 2nd edition, 1975; 3rd edition, 1998. ISBN 0-471-30932-X
R.J. MacKay and R.W. Oldford. "Scientific Method, Statistical Method and the Speed of Light", Statistical Science 15(3):254–278, 2000.

[edit] External links

Wikibooks has a book on the topic of

Special Relativity

Speed of light in vacuum (at NIST)
Data Gallery: Michelson Speed of Light (Univariate Location Estimation) (download data gathered by A.A. Michelson)
Switching light on and off (news article on stopping light)
Beam smashes light barrier (news article on group velocity experiment)
Subluminal (Java applet demonstrating group velocity information limits)
Light discussion on adding velocities
Discussion on binary stars and adding of velocities
Surpassing speed of light (an interesting pseudo-scientific theory)

Retrieved from "http://en.wikipedia.org/wiki/Speed_of_light"

Categories: Light | Units of velocity | Special relativity | Fundamental physics concepts

Technology

2007-09-27T15:43:00.001+02:00

Only on msnbc.com
Think your room is messy? Maybe not
Clicked: Ninjas, this means war

DESY Hamburg

More technology and science news

Microsoft rolls out Live Search improvements

LinkedIn to allow photos after resisting

T-Mobile introduces new Sidekicks

News site Digg adds filtering options

Showery weather might halt Dawn launch

Firefly's flash can bring sex or death

Intel wins mobile WiMax chip deal with Nokia

Security firm: AOL has hole in IM software

Migrating birds may 'see' Earth's magnetic field

Why all the hype for 'Halo 3?'

Asteroid Might Hit Earth in 2880

2007-09-26T11:59:00.001+02:00

Asteroid Might Hit Earth in 2880, Unless it is Painted

An asteroid first spotted in 1950 has a maximum 1-in-300 chance of striking the Earth in the year 2880 scientists will report Friday in the journal Science. The odds, which might turn out to be zero, are for now greater than for any other asteroid ever determined to be a threat.

However, scientists are not worried; a little chalk, some charcoal, or perhaps a giant bucket of paint and the asteroid known as 1950 DA could be flung harmlessly off course if need be.

Asteroid 1950 DA

Details of the asteroid's threat, and why you shouldn't worry. [READ MORE]

The trick lies in a strange natural phenomenon: solar-powered orbital mechanics.

The idea goes back to a scientific paper written by Russian engineer I.O. Yarkovsky a century ago and since lost. Yarkovsky is said to have proposed that the Sun warms an asteroid more on the "day" side than on the "night" side. The warmer side of the rock emits more thermal radiation, creating a slight difference in momentum that gently nudges the object in a manner similar to how a rocket is propelled.

Over hundreds of years, the movement can be significant, scientists say.

So paint it

Joseph Spitale of the University of Arizona will report in the journal that knowledge of this Yarkovsky effect, along with a little dynamite or some paint, could be employed to alter the path of any asteroid known to be on a collision course with Earth.

"It would not be terribly costly to deliver an amount of TNT necessary to pulverize the top centimeter or so of the surface," Spitale told SPACE.com. "The debris generated in this way could be useful in changing the surface thermal conductivity. Although you might not retain the debris generated in this way, such an approach might alter the surface character in other useful ways."

A more costly approach, Spitale said, would be to paint the asteroid or cover it with dirt in order to change how it reflects sunlight.

Any of these methods would require a serious and expensive space mission.

"In terms of mobility per unit mass launched, I think the TNT may win," Spitale said, "but I suspect that the maximum effect you could attain that way may be smaller than by using the other more expensive approaches."

Spitale's ideas, wild as they might seem, are no more outlandish than the long-running suggestion that an incoming asteroid could be deflected or destroyed with nuclear explosions. Others have even suggesting attaching a giant solar sail to a space rock in order to nudge it off course.

Details of any of these methods, including the science of how they would work, still need to be investigated. It would not be good, for example, to blow up an asteroid with a nuclear warhead only to have the pieces slam into Earth.

"I think the biggest problem currently is developing the ability to compute the consequences of such an action accurately enough to be confident that you're fixing the problem and not making it worse," Spitale said. "We're getting there with the Yarkovsky calculations."

Spitale is not the only scientist thinking along these lines.

Impact in 2880?

Suggestions for how to employ the Yarkovsky effect to save Earth stem from work done by several leading asteroid experts and led by Jon Giorgini of NASA's Jet Propulsion Laboratory. The team has been studying an asteroid discovered in 1950, later lost, then rediscovered in 2000.

The orbit of the asteroid, called 1950 DA, has been observed over a time frame spanning five decades. This allowed the researchers to project its approximate path farther into the future than is possible with most asteroids. The result: 1950 DA currently has at most a 1-in-300 chance of hitting Earth on March 16, 2880.

Because 1950 DA is large -- more than 1 kilometer (0.6 miles) across -- the consequences would be grave and global. Clouds of debris would create a multi-year winter that would kill off many species and might even threaten civilization.

In another study in the April 4 issue of Science, Giorgini and his colleagues map out the projected path of 1950 DA and discuss the chance that it might hit Earth.

The asteroid swings inside Earth's orbit on its closest approach to the Sun, then travels out to the main asteroid belt between Mars and Jupiter. Over the next eight centuries, it will approach Earth 13 times and pass near Mars twice.

Giorgini said in an e-mail interview that the Yarkovsky effect, amplified by close encounters with the planets and their gravity, have the potential to advance or delay arrival at the orbit intersection point in 2880 by several days. Which is to say that it may well miss Earth. Other factors, including direct pressure from solar radiation and the gravity of thousands of other asteroids, could cancel out some or all of the Yarkovsky effect.

Figuring out the asteroid's exact encounter circumstance, as astronomers call it, is difficult for now. Because the researchers know so little about the rock's surface and shape, they cannot accurately account for the Yarkovsky effect. They can only map out a range of outcomes the effect might produce.

"We need to know about the physical characteristics of these objects to do precise long-term hazard predictions," Giorgini said.

In fact, the odds of impact in 2880 may be practically zero, depending on the asteroid's axis of rotation, which greatly affects how it absorbs and radiates solar energy. Radar data indicates two general possibilities.

"The situation is similar to a biased coin that is known to give one side 80 percent the time, but it is not known which," Giorgini explained. "All you can say is the chance of heads is either 20 percent or 80 percent. So we say the collision probability of 1950 DA is either near the maximum of 1-in-300 or near zero. There's a range. It may take years or decades to determine which."

If the collision is eventually determined to be imminent, Giorgini and his colleagues agree with Spitale: Mitigation is possible. But they suggest slightly different methods.

"The study shows how the asteroid could be diverted, if need be, by covering its surface with chalk or charcoal, or by collapsing a solar sail spacecraft mission around the asteroid," Giorgini said. "These things would change the way it reflects light and emits heat, thus allow sunlight to do the work."

Yarkovsky's dark side

Ironically, the Yarkovsky effect has natural consequences that seem to herd space rocks toward Earth.

Smaller asteroids, especially, are more vulnerable to being propelled by the uneven solar heating. A study released last November found that bits and pieces created when two asteroids collide undergo changes in their orbits do to their new surface properties.

Computer simulations led by the Southwest Research Institute's William F. Bottke, Jr. found that some of these smaller asteroids can be propelled to the edges of gaps in the main asteroid belt -- regions of the belt that have been swept clean by the gravitational effects of Jupiter.

Unfortunately, when asteroids enter these gaps, Jupiter's gravity tends to fling them into near-Earth orbits.

An earlier study by European researchers, released in 2000, also showed that the Yarkovsky effect feeds these portals with ancient chunks of stone and iron, which can then be hurled Earthward.

When researchers improve their understanding of the Yarkovsky effect, as well as their knowledge of the surface properties of asteroids, they will learn whether certain asteroids actually target Earth. Perhaps equally important, they'll have figured out how to change that fate.

Asteroid on way to Earth

2007-09-26T11:48:00.000+02:00

Bliski susret sa asteroidom 2002 NY 40

Friday, August 16 @ 18:59:41 CEST
Priprema: Marino

Da li nam prijeti veća opasnost od kometa ili asteroida? Asteroid 2002 NY 40 će se u noći 17/18. (subota/nedjelja) kolovoza najviše približiti Zemlji, te će nas “promašiti” za nešto više od 500 000 km, i ne predstavlja opasnost po našu planetu.

Obzirom na putanju i sjaj asteroida u maximumu od M=9 biti će ga moguće vidjeti i sa dalekozorom, zbog specifičnosti putanje lako uočiti i gotovo u “real-time” vremenu pratiti njegovo gibanje u svemiru, što nije čest slučaj u astronomskim promatranjima (ako izuzmemo meteore).

Njegova će putanja za naše zemljopisne koordinate započeti iz smjera Jarca, prolaziti će granicom Dupina i Orla, proći gotovo “kroz” M71, nastaviti dalje prema Labudu odnosno Liri, da bi se potom izgubio u jutarnjem sumraku, a kasnije ga zbog udaljavanja od Zemlje i brzog opadanja sjaja više neće biti moguće vidjeti skromnijim astronomskim instrumentima.

Vrijedilo bi istaknuti da je 2002 NY 40 otkriven na vrijeme i da nije postojala mogućnost njegovog udara u Zemlju, što nije bio slučaj sa nekim nedavno otkrivenim asteroidima (2002 MN na 120 000 km od Zemlje!). Do samo prije nekoliko godina otkrivali smo svega nekoliko desetaka kometa i asteroida godišnje i bili uljuljani u vjerovanje da se asteriodni pojas (sva sila i briga većih i manjih gromada kamenja, željeza, leda i sl.) nalazi “daleko” od Zemljine putanje, te da ne predstavlja gotovo nikakvu opasnost po Zemlju.

Uporabom novih tehnologija te razmjenom i obradom informacija (linear, internet i dr.) ta se slika drastično promijenila, počeli smo otkrivati na stotine i stotine novih kometa i asteroida od kojih su mnogi svrstani u tzv NEO objekte (objekte koji prolaze blizu Zemlje) koji predstavljaju ozbiljnu prijetnju našoj civilizaciji. Donedavni problem šačice astronoma u svijetu i njihovih, nešto brojnijih, kolega astronoma-amatera (amatera- samo po tome što za svoj rad nisu plaćeni) ubrzo je postao visoko rangirana opasnost (jedna od 10 najvećih) po našu civilizaciju.

Zadnjih se godina ovoj potencijalnoj opasnosti pristupa sa dužnom pažnjom, čovjek je danas, potencijalno, u mogućnosti na vrijeme otkriti i ukloniti ovakvu opasnost. Nedavni susret Europskih promatrača asteroida – MACE 2002 (www.astro.hr) u Višnjanu doprinos je takovim nastojanjima. Zvjezdarnica Vidulini, za koju se nadamo da će biti operativna 2004. godine također će se priključiti potrazi za malim tijelima Sunčeva sustava.

Nadajmo se da zbog svjetlosnog zagađenja nećemo prekasno uočiti malu svijetlu točkicu čija je putanja na susretnom kursu sa Zemljinom.

Hotel Eden Rovinj

2007-09-25T11:59:00.000+02:00

Hotel Eden

L. Adamovića bb, 52210 Rovinj (Istrien) (Show map)

Overview

Photos

How to Book or Cancel

Maistra's best hotel offers its guests an opportunity to enjoy a peaceful and relaxed atmosphere which pervades its every corner.

Located on the edge of a unique and wonderful hundred-year old nature park called Zlatni Rt - Punta Corrente, with its long-term tradition, this hotel will satisfy each guest's demands.

A vacation in a four-star hotel which has become a tradition in Rovinj's tourist resort will enable you to combine relaxation in a calm, healthy oasis and the buzz of vibrant entertainment.

Hotel Eden has become a member of the respectable international collection: Special Hotels of the World.

Rooms: 330

Availability

Please enter the dates of your stay to check availability

When would you like to stay?

Check-in date

Check-out date

Hotel Facilities

General

Restaurant – Bar – 24-Hour Front Desk – Elevator

Activities

Fitness Centre – Massage – Indoor Swimming Pool – Outdoor Swimming Pool

Location

Beach

Internet

Wireless internet is available in the entire hotel and is free of charge.

Guest Parking

Free Public parking is possible on site.

Hotel Policies

These are general hotel policies. As they may vary per room type; please also check the room description.

Check-In

13:00 – 00:00 hours

Check-Out

07:00 – 11:00 hours

Cancellation

If cancelled up to 5 days before date of arrival, no fee will be charged.

If cancelled later, the first night will be charged.

In case of no-show, the total price of the reservation will be charged.

Children and extra beds

All children under 2 years stay free of charge when using existing bedding.

All children under 2 years stay free of charge for cots.

There is no capacity for extra beds in the room.

Maximum capacity of babycots in a room is 1.

Extra beds and baby cots are upon request and need to be confirmed by the hotel.

Pets

Pets are not allowed.

Accepted credit cards

American Express
Visa
Euro/Mastercard
Diners Club
Maestro

The hotel reserves the right to pre-authorise credit cards prior to arrival.

Hotel information

The Eden is the perfect place to live the real Rovinj experience. Your stay will be enhanced by the impeccable service delivered by the competent and friendly staff.

The opulent green of the soft lawn and beautiful swimming pools pave the way to the hotel's own bay. Open all-year round for lovers of tranquility, entertainment or sports and recreation, we can satisfy the most demanding guests.

There are diverse entertainment facilities such as hobby workshops, Croatian language school and various land or water sports like water polo, basketball, mini golf, table tennis, tennis (12 clay courts, 4 in a roofed tennis hall, approximately 150m from the Eden Hotel), badminton, shooting range and boccie.

Our entertainment programs includes a diverse day and night itinerary for adults, an outdoor terrace with a stage, indoor hall (bar and stage), and mini-club with entertainment for children. You can enjoy live music, various shows, folklore performances and the a capella vocal ensembles called Klape.

Food & beverage

It is an ideal place for those looking for quietness and the good service of a four star hotel. Our restaurants offer a varied and extensive menu of traditional Croatian cuisine, adapted to suit the international palate.

Our excellence is based on the quality of the ingredients we use, as well as the efficiency and dedication of both our kitchen and waiting staff. You can choose from Burin National Restaurant, Oleander Grill, Pool Bar, Aperitif Bar or the Muntrav Caffeteria.

In addition, we also provide an extensive and select choice of menus for all occasion, banquets, conventions, etc. with quality ingredients, exquisite cuisine and presentation. The room service menu has been designed hand in hand with the restaraunt menu.

Supplements for stays under 3 nights
Supplement for dinner: EUR 18,00 per person

Supplements for stays over 3 nights
Supplement for dinner: EUR 15,00 per person

Room information

Our large, beautifully decorated rooms are fully-equipped.

Area information

Rovinj, with 13,000 inhabitants, is a fairytale town, irresistible for its colourful appeal and unique beauty. At seventeen centuries old, it remains young and lively, welcoming every nation, every age, in every season.

Sundrenched and surrounded by lush Mediterranean vegetation, it was beautifully built with the white stone on which it now stands. Discover yourself roaming through the labyrinths of Rovinj’s charm.

Important information

Beach chairs and parasols are free of charge.
Room service is available from 7:00 to 23:00.

----------------------------------------------------------------------------------------------
----------------------------------------------------------------------------------------------

Revolutionary Watches

2007-09-25T11:50:00.000+02:00

Look to this revolutionary watches..
Japaneses aren`t normal..:)

Reminiscent of some kind of satellite tracking system, the LED's in Geomesh light up in various patterns that cryptically tell the time. It's a very unique display & uses the horizontal and vertical lights to indicate hours & minutes.


Colors
Max. Wrist Size	180mm (approx.)
Case Dimensions	26mm x 45mm x 11mm
Weight	100 grams

Available in a brushed Gunmetal finish with either White, Blue or Multi-color LED's.
The face is a mirrored grid with 27 LED's.
Hours are indicated by counting the vertical lights & minutes by the horizontal lights. The minute lights can indicate 5 mins each light or 1 minute depending on the configuration - sounds complicated, but not really that difficult.

For example, take a look at one of the Multi-color LED watch photo's. The Green (vertical) lights are hours. The Yellow (horizontal) lights are 5 mins each & the Red 1 minute each. The same applies to the other models, just the color is different.

Please note that the strap on this watch is quite short. Be sure to measure your wrist, the maximum size is 180mm (7 inches)

Water Resistant
1 Year Warranty
Time only
Stainless Steel strap & caseback
Mirrored face
English & Japanese Instructions

-----------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------

Colors
Max. Wrist Size	225mm (approx.)
Case Dimensions	27mm x 40mm x 10mm
Weight	90 grams

The strap is a continuous stainless steel band that wraps around your wrist with a matrix of punched out holes. Beneath the surface are 29 super bright LED's which illuminate to indicate the time. There are 3 models available.

The watch's LED's animate in a cascade effect when showing the time. (Button B skips the animation & jumps straight to the time)

On the multi-color LED model the red lights (12) indicate the hour, the green (3) indicate 15 minutes each & the Yellow (14) are 1 minute each.
By telling the time in this way it makes it very easy to see if its roughly quarter-past, half-past or quarter-to the hour. With each green LED worth 15 mins; then 2 lit equals 30 mins.

The watch is also available in All-Red & All-Green LED if you prefer the single color look. The etched markings on the strap allow you to distinguish between hours & minutes on all versions - but the multi-color version is by far the easiest model to read the time on, especially at night.

The strap is easily adjustable at home, no need to use any tools, and can fit up to a 8.5 inch wrist. (22.5 cm)

Time Only
English & Japanese Instructions
1 Year Warranty
Stainless Steel Strap
Water Resistant 3ATM

-----------------------------------------------------------------------------------------------

-----------------------------------------------------------------------------------------------

The JLr7 (which is named after the top row of the watch) comes from the minds of Eri & Eiichi (e35) who theme their designs and artwork on geometric patterns. We love the way this seemingly random pattern of lights is able to tell the time in a futuristic manner.

Colors
Max. Wrist Size	210mmmm (approx.)
Case Dimensions	28mm x 40mm x 11mm
Weight	130 grams

The whole watch is brushed with a dark gunmetal finish and an all black crystal face. The grid of L-shaped digital segments on the face light up to reveal the time.
When the button is pressed the watch starts a computerized animation sequence with a random pattern of lights & then displays the time. Between 6pm & Midnight the watch animates automatically every 15 mins to give the effect that it is malfunctioning. (this feature can be turned off)

There are 12 lights for the hour, 3 for "quarter past", "half past" & "quarter to" and 14 lights for the times in between. There are also 3 other lights which show the seconds ticking by. The watch face has some subtle dark grey markings which distinguish the borderline between hours, minutes & seconds.

Time Only
English & Japanese Instructions
Light up function, ON or OFF

Top20 Cars by the words of people

2007-09-25T08:56:00.000+02:00

Top 20
Audi R8
BMW M3
BMW M6
Bugatti Veyron 16.4
Chevrolet Corvette Z06
Dodge Viper SRT-10
Ferrari 430 Scuderia
Ferrari Enzo
Ford GT
Ford Shelby GT500KR
Koenigsegg CCX
Lamborghini Murcielago LP640
Mercedes-Benz SLR 722 Edition
Mitsubishi Lancer Evolution X
Nissan NISMO 350Z
Porsche 911 GT2
Porsche 911 Turbo
Porsche Carrera GT
Saleen S7 Twin Turbo
Subaru Impreza WRX STI

Autosalon Frankfurt 09/2007

2007-09-25T08:54:00.000+02:00

Autosalon Frankfurt 09/2007

A total of 1,081 exhibitors from more than 40 countries will attend this year's IAA, once again a significant increase over the already strong exhibitor turnout at the last IAA (2005: 1,041 exhibitors).
World Debuts

2008 Saab Turbo X	2008 Lamborghini Reventon
9/12/2007 – Saab celebrates three decades of turbocharging by launching the Saab Turbo X, a driver-focused performance car with an active all-wheel-drive system.	9/11/2007 – A super car without equals: the Lamborghini Reventon is a road vehicle with an extreme specification and, at the same time, a limited edition masterpiece.
2007 Renault Laguna Coupe Concept	2007 BMW AC Schnitzer GP3.10 Concept
9/11/2007 – Renault has chosen the Frankfurt Motor Show to unveil Laguna Coupe Concept, its vision of a top-of-the-range grand tourer Coupe.	9/10/2007 – This exciting 3-series concept from AC Schnitzer features an M5/M6 engine, modified to run on LPG (Liquified Petroleum Gas).
2007 Mercedes-Benz Brabus Bullit	2008 Mercedes-Benz C 63 AMG Estate
9/10/2007 – The ultimate wolf in sheep’s clothing with V12 Biturbo engine, 720 bhp, 974 lb-ft of torque and a top speed of more than 224 mph.	9/7/2007 – The C 63 AMG Estate has been officially unveiled.
2007 Hyundai Veloster Concept	2008 Audi RS 6 Avant
9/5/2007 – The Veloster is a futuristically designed two-plus-two. A panoramic glass roof and other futuristic styling cues help project a high-tech image.	9/5/2007 – Outstanding top performance and maximum dynamism combined with excellent suitability for everyday use are the impressive features of the new Audi RS 6 Avant.
2008 Opel Astra OPC Nurburgring Edition	2008 Mercedes-Benz SLK 55 AMG Black
8/29/2007 – The Astra OPC Nurburgring Edition is a limited special edition version of the successful three-door model.	8/28/2007 – The new Black Series is an even more driver-focused variant of the V8-powered SLK 55 AMG Roadster.
2009 Jaguar XF	2008 Ferrari 430 Scuderia
8/28/2007 – Challenging convention and setting its own rules, the new Jaguar XF fuses the style and performance of a sports car with the refinement, space and sophistication of a luxury saloon.	7/19/2007 – The 430 Scuderia is a truly high-performance 2-seater which demonstrates how Ferrari's Formula 1 know-how is carried across to its production cars.
2008 Porsche 911 GT2	2008 Mercedes-Benz C 63 AMG
7/16/2007 – Based on the current 911 Turbo, the 911 GT2 will easily ascend to lead the impressive Porsche family of vehicles.	7/4/2007 – A combination of expressive design, a decidedly sporty interior and a high level of everyday practicality makes the new C 63 AMG a unique high-performance car.

Other Exhibits

2008 Aston Martin DBS 2008 Audi A4 S-line 2007 BMW AC Schnitzer Z4 Profile Concept 2009 BMW M3 Coupe	2007 Pagani Zonda R 2007 Peugeot 308 RC Z Concept 2007 Subaru Impreza WRC Concept

Acura
Alfa Romeo
Ascari
Aston Martin
Audi
Bentley
BMW
Bugatti
Buick
Cadillac
Caparo
Caterham
Chevrolet
Chrysler
Citroen
Dodge
Ferrari
Fiat
Fisker

Ford
Formula 1
Gumpert
Holden
Honda
Hummer
Hyundai
Infiniti
Invicta
Jaguar
Jeep
Koenigsegg
KTM
Lamborghini
Land Rover
Lexus
Lotus
Maserati
Maybach

Mazda
McLaren
Mercedes-Benz
MG
Mini
Mitsubishi
Morgan
Nissan
Noble
Opel
Pagani
Panoz
Peugeot
Pontiac
Porsche
Renault
Rinspeed
Rolls-Royce
Saab

Saleen
Saturn
Scion
Seat
Shelby
Spyker
SSC
Subaru
TechArt
Tesla
Toyota
TVR
Ultima
Vauxhall
Volkswagen
Volvo
YES

Updates

2008 Ferrari 599 GTB Fiorano by Novitec

August 31, 2007
The German tuning firm Novitec has revealed a styling package for the Ferrari 599 GTB Fiorano.

2007 Maserati Edo Competition MC12 Corsa

August 11, 2007
Edo Competition was not shy to add some finishing touches to the ultra-exclusive MC12 Corsa, in the form of a new suspension, exhaust system, brakes, and wheels.

Photo Update: 2008 Honda Civic Mugen Si Sedan

August 7, 2007

2008 Bentley Continental GT Speed - wallpaper

August 2, 2007
A potent addition to the company’s successful Continental series, the GT Speed extends the appeal of the Continental GT coupe to those who place a high value on outright performance.

News & Articles

255.83 mph: SSC Ultimate Aero Breaks Speed Record
9/17/2007 – Confident of the 1183 bhp vehicle’s abilities, SSC beat Bugatti Veyron's speed record by 3.11 mph.

The Project Kahn SLR McLaren
9/10/2007 – Project Kahn's SLR includes a sports exhaust system, lowered suspension, Kahn SLR body styling package, 21-inch alloy wheels and a 60 bhp engine upgrade.

Wallpapers

Lamborghini Galardo-The Fighting Bull From Spain

2007-09-25T08:46:00.000+02:00

Gallardo - The Fighting Bull From Spain

Gallardo Model Year 2006

The technical modifications made to the Gallardo Spyder and Gallardo SE also apply to the Gallardo Model Year 2006.

Thanks to an increased engine power of 520 bhp and lower ratio gears, the Gallardo MY 06 can reach a top speed of 196 mph and accelerate from 0 to 62 mph in 4 seconds.

Equipment levels have also been enhanced and include such items as the new Lamborghini Multimedia System (CD-changer, MP3 player and radio), new colors for the interior trim, a non-smoking version (where the cigar lighter is replaced by a 12V socket).

There are also three new colors to choose from: these are Verde Faunus (green), Blu Fontus (blue) and Grigio Proteus (grey). Some changes have been made to the existing color range: Rosso Leto replaces Rosso Metis (red) and Nero Serapis replaces Nero Osyris (black).

There are also new colors for the interior leather: Arancio Leonis (orange) replaces "Mira" and Rosso Centaurus (red) replaces Rosso Mysia (red).

Optional equipment for the Gallardo 06 includes the rear video camera and a TV-tuner (not available for USA/Canada and Japan).

Other options include new "Callisto" wheels and the sports setup for the MY 06 model, with racing steering wheel, steering and suspension.

There is also a range of customized options for the Gallardo MY 06 (under the name “Privilege Programme”), which gives customers the possibility to purchase an even more exclusive and truly unique car.

The Gallardo

Ferruccio Lamborghini – born under the zodiac sign of Taurus – when he founded the famous super car company, that since then bears his name, gave to it the symbol of the fighting bull.

Later, in the ’60 decade, when the Miura was introduced, he named the car after a famous bull’s race, and this practice became a tradition for the House of the Bull.

Honoring this tradition, the Management of Automobili Lamborghini have decided to baptize their latest model with the name of a fighting bull’s breed: the Gallardo (pron.: ga:yardo). Most people probably are not aware that the origins of the fighting bull proceed from five main breeds, that is: Cabrera, Navarra, Vasquena, Vistahermosa and Gallardo.

The Gallardo breed was created in the XVIII century. It draws its name from Francisco Gallardo and his brothers – cattle breeders at (of the) Santa Maria (Cadiz) – who, thanks to the good results obtained by their bulls’ behavior in the arena, reached a considerable prestige in the most important plazas de toros.

The Concept

Designed to redefine its segment as the best high performance sports car and driving behavior that fits its driver in every situation. The Gallardo is the synthesis of a true sports car that can be used on an every day basis. While matching these two apparently conflicting objectives, the guideline for Lamborghini engineers has been to fulfill the necessary comfort requirements without any compromise in the performances expected of a true Lamborghini car.

The choices for engine, transmission, space frame and body, suspensions, brakes and electronics are then all in line with such an objective. The result is a compact (length 167.7 inches) 2-seater high performance car (maximum speed over 190 mph), that can be driven with pleasure both on race tracks and on long distance journeys on country and city roads.

The layout has been conceived to reach the high performance targets, on the basis of the sports-oriented concept for which Lamborghini is well known.

The basic characteristics of such a layout are:

mid-rear mounted engine, with the gearbox behind the engine
permanent four-wheel drive system
independent double wishbone suspension system
aluminum space frame
low centre gravity
weight distribution 42% front, 58% rear
two front mounted water radiators and one side mounted oil cooler

Particular attention was paid to achieve the correct weight distribution, true to Lamborghini’s engineering tradition. In fact, the chosen weight distribution is the optimal for a sports car, with advantages for traction, braking and handling.

The lowering of the centre of gravity has also been a fundamental guideline, which also lead to the engineering decisions for engine and transmission layout.

2006 Lamborghini Gallardo

Specifications

Engine
Type:	V10
Displacement cu in (cc):	303 (4961)
Power bhp (kW) at RPM:	520(362) / 8000
Torque lb-ft (Nm) at RPM:	376(510) / 4250
Redline at RPM:	n.a.
Brakes & Tires
Brakes F/R:	ABS, vented disc/vented disc
Tires F-R:	235/35 ZR19 - 295/30 ZR19
Driveline:	All Wheel Drive
Exterior Dimensions & Weight
Length × Width × Height in:	167.7 × 74.1 × 45.4
Weight lb (kg):	3153 (1430)
Performance
Acceleration 0-62 mph s:	4.0
Top Speed mph (km/h):	196 (315)
Fuel Economy EPA city/highway mpg (l/100 km):	9/15 (17.0)

Base Price: 2006 Lamborghini Gallardo - $175,000 (last update: 2/22/2007)

Photo Gallery 2006 Lamborghini Gallardo

BUGATTI VEYRON 16.4

2007-09-24T21:18:00.001+02:00

BUGATTI VEYRON 16.4
Manufacturer	Bugatti Automobiles S.A.S.
Parent company	Volkswagen AG
Production	2006–present (around 300 to be produced)
Class	Supercar
Body style(s)	2-door coupé
Layout	Mid-engine, all-wheel drive
Engine(s)	8.0 L quad-turbocharged W16
Transmission(s)	7-speed dual clutch sequential manual
Wheelbase	2710 mm (106.3 in)
Length	4462 mm (175.8 in)
Width	1998 mm (78.7 in)
Height	1206 mm (47.5 in)
Curb weight	1889 kg (4162 lb)
Designer	Hartmut Warkuss

Bugatti Veyron 16.4 joined the league of supercars with a series of superlative modifiers such as the ´fastest, most powerful and most expensive´ street-legal production cars in the world. The ever powerful Veyron engine is capable of yielding 1020 to 1040 metric HP, and so the Veyron 16.4 supercar is now better known as the ´1001 horsepower´ car.

The famous sports car manufacturer, Bugatti Automobiles SAS, a subsidiary of Volkswagen AG, owns the prestigious title for manufacturing the super performer of the world. The name ´Veyron´ is attributed to the French racing driver Pierre Veyron who won the title ´24 hours of Le Mans´ in 1939 for Bugatti. Bugatti, with its long years of experience in making the traditional racing cars since the early ´90s, tries the track in the modern era with a well-advanced version of their technology applied in the Veyron 16.4.

Bugatti Veyron is an exclusive sports car for the 21^st century. It exemplifies the perfect blending of design with technological concept.

Offering a high performance with serious measures to ensure safety was the major concern at Bugatti while yielding a maximum performance speed of 252.3 mph (406 km/h) to this leader of the modern era racing cars. Thanks to the single-piece carbon-fiber monocoque technology that absolutely suited the Bugatti Veyron supercar and scored the maximum points at various crash tests. Adding to this perfect body structure are other safety measures such as the airbags and the PAX system applied on the wheels and tires.

Another innovative safety measure applied is the rear spoiler of this sports car that performs double action – it provides the necessary downforce at high-speed driving, and it acts as a ´parachute brake´ during sudden braking. It helps to add additional air resistance to the brakes and thus reduces the braking distance of this supercar to great extent.

The W16 alloy engine is an important feature of the Veyron 16.4. The 16 cylinders are arranged in 4 banks of 4 cylinders. The engine uses four turbochargers that are capable of a displacement of 8.0L with an 86X86 mm bore and stroke. The dual-cultch DSG computer controlled manual transmission system sets the Veyron sports car to have full automatic transmission. The system is provided with seven gear ratios through the shifter paddles situated behind the steering wheel, and they offer 8ms shift time.

The wheels and tires are also modified to facilitate an improved performance of the new supercar. The all-wheel-drive helps to transfer the power efficiently to the road while speed driving. The Michelin run-flat tires used in the Veyron meet all the safety standards and suit the adventurous driving situations and racing conditions.

The brake system consists of a cross-drilled and turbine-vented carbon rotors. Each caliper is provided with eight titanium pistons. The braking system of Veyron supercar is so effective that it can produce a deceleration of 1.3g on road tires.

The interior of the Veyron 16.4 sports car features an exceptional design that exhibits the creativity and the aesthetics of the designer. The superb quality leather, the metallic trim, and the ergonomically set instrument panel add to the touching cockpit experience.

2006 Bugatti Veyron 16.4 sets itself an example to the luxury car world in terms of its design, technology, and the performance.

Picture of Red-black Bugatti Veyron 16.4 on the road race

Picture of Blue-black Bugatti Veyron 16.4 parked

Picture of Blue-black Bugatti Veyron 16.4 in dark

Picture of Brown Bugatti Veyron 16.4 leather interior

APRILIA MANA 850

2007-09-24T20:34:00.000+02:00

APRILIA MANA 850

MaxMoto News from Milan 14/11/06.

We've taken a big interest in this bike since the Gilera Ferro prototype was first shown at the Milan show in '03.

The headline is obviously that this is a revolutionary automatic motorcycle, built with Aprilia's and parent Piaggio's extensive experience of CVT transmissions.

The CVT system is a belt and variable diameter pulley system that provides an infinite number of gear ratios, making the bike smooth and very easy to ride. It also has some performance advantages and it will satisfyingly out drag almost anything (including top of the range sports bikes) from the traffic lights.

Aprilia have set up the CVT with three automatic settings and a pseudo sequential seven speed manual. The auto settings are touring (for good economy), sport (for maximum performance) and rain (for a softer power delivery for good traction in the wet), and they are interchangeable on the move with a handlebar switch. The pseudo manual option is controlled also via the handlebars (see pic) or through the traditional left foot selector. There is no clutch lever.

The commuter is clearly in Aprilia's sights here, with a bike that is easy to ride and well suited to town riding, but also has the convenience of a helmet storage in the false fuel tank, with the airbox being moved to between and to the left of the v-twin cylinders and the real fuel tank to under the seat.

The engine is a torquey, easily maintained and economical 90° v twin developed initially by parent Piaggio's engine department with 75bhp and 56lbft, single overhead cams, a dry sump and stainless steel exhaust.

The frame is a rigid tubular steel trellis design that should make the bike handle like an Aprilia should.

The front end is chunky 43mm upside down forks with radial brakes, steel braided lines and 320mm discs.

The rear has an aluminium swing arm with the shock absorber moved to one side to allow for a shorter, faster turning wheelbase.

We believe availability will be in the summer 2007 with a price of around £5,250.

Have you got something you'd like to say on this topic? If so, go to MaxMoto's Message Board for the Aprilia Mana Auto ( 106 comments).

Would you like to receive regular news items like this? And be entered into our regular prize draws? Then, Join our Newsletter.

Click on images to enlarge

Aprilia 850 Mana (HiRes)

Aprilia Mana

Aprilia Mana 850

Aprilia Mana SportGear

Youtube555

Physical Exercising

Exercise Program Information:

Healthy Eating

Family Meals

Stocking Up on Healthy Foods

Nutrition

Chocolate Milk - a Sports Drink?

Do You Need a Multivitamin Supplement?

Organic Foods

Fruits and Vegetables for Healthy Eyes

Foods for Low Fat and Low Carb Diets

Healthy Salads

Nutritional Jungle

Healthy and Safe Fish For Your Kids

Before You Buy a Cookbook

Breaking The Speed Of Light

Four billion km/h

The Cloack Of Invisibility

Altered Reality

More Invisibility Cloak Components

The Complete System

The Speed Of Light

Contents

[edit] Overview

[edit] Communications and GPS

[edit] Physics

[edit] Constant velocity from all inertial reference frames

[edit] Luminiferous aether (discredited)

[edit] Interaction with transparent materials

[edit] Accelerated frames of reference and general relativity

[edit] "Faster-than-light" observations and experiments

[edit] "Slow light" experiments

[edit] History

[edit] Medieval and early modern theories

[edit] Measurement of the speed of light

[edit] Early attempts

[edit] Astronomical techniques

[edit] Earth-bound techniques

[edit] Laboratory-based methods

[edit] Speed of light set by definition

[edit] Relativity

[edit] See also

[edit] References

[edit] Footnotes

[edit] Historical references

[edit] Modern references

[edit] External links

Technology

Asteroid Might Hit Earth in 2880

Asteroid on way to Earth

Hotel Eden Rovinj

Hotel Eden

Availability

When would you like to stay?

Check-in date

Check-out date

Hotel Facilities

General

Activities

Location

Internet

Guest Parking

Hotel Policies

Check-In

Check-Out

Cancellation

Children and extra beds

Pets

Accepted credit cards

Hotel information

Food & beverage

Room information

Area information

Important information

Revolutionary Watches

Top20 Cars by the words of people

Autosalon Frankfurt 09/2007

Lamborghini Galardo-The Fighting Bull From Spain

Gallardo - The Fighting Bull From Spain