Should we care about the speed of light or faster

Should we care about the speed of light. This is just on different note I am not a physicist but as reader loved this info

A change in how scientists conceptualize relativity could alter how we think about causality and turn physics on its head. When physicists announced last week that they had detected subatomic particles, called neutrinos, that appeared to be traveling faster than the speed of light, it seemed to be an exception to a cosmic speed limit set by Albert Einstein's special theory of relativity.

Einstein's theory, which he proposed in 1905, describes the relativity of motion, particularly the motion of anything moving at or close to the speed of light. At the time, people believed that light waves, just as sound waves, ocean waves or shock waves, had to travel through a medium. But rather than air, water or ground, they believed light waves traveled through a substance called ether, less tangible than air, that pervaded the universe.

Scientists assumed that the laws of physics would be different for an object at rest with respect to the ether, and with the proper experiments it would be possible to figure out what was truly at rest, according to Peter Galison, a professor of physics and the history of science at Harvard University.

"Einstein got rid of that," Galison said. "There are no physical properties that go with the statement 'I am truly at rest.' That's really what special relativity is about."

In other words, the properties of physics are the same for me whether I am riding my bicycle or sitting on a park bench. Special relativity, however, does not apply to acceleration. Einstein would tackle this later in his general theory of relativity.

Special relativity is also based on a second assumption that gives the speed of light — 186,000 miles per second (300 million meters per second) — in a vacuum a special status. Einstein postulated that light always travels at the same speed for every observer, regardless of that observer's speed, Galison explained.

So, if you have a fast enough car, in theory, you could catch up to a bullet. But you could never catch up to, or even reduce the apparent speed of a pulse of light, regardless of whether you were driving toward it or away from it.

Ultimate speed limit

Under Einstein's theory, the speed of light becomes a sort of ultimate speed limit. In fact, objects with mass, be they cars or neutrinos, can't reach the speed of light because they would need infinite energy to do so, according to the theory.

Some experiments have appeared to play with the speed of light, but these effects are illusory, according to Galison. Light traveling through different mediums, such as chilled sodium gas, does slow substantially, but this is because the light is being bounced between the atoms within the medium. But between interactions with atoms, it is still traveling at 186,000 miles per second (300 million meters per second), he said.

Claims that it's possible to push light beyond 186,000 miles per second (300 million meters per second), are equally illusory, Galison said.

Galison uses a hypothetical to explain why. If you shine a laser pointer on the surface of the moon and flick your wrist to sweep across the surface, wouldn't that mean that the bright dot is crossing the surface of the moon faster than the speed of light? No, because nothing is actually crossing the surface of the moon — the dot isn't an actual object, it is just a series of photons in the laser beam hitting the surface.

"For 100 years, people have used these and more sophisticated paradoxes to try to say, 'Well isn't there this way to exceed the speed of light?'" Galison said. "They usually turn out to involve accelerating motion, something that is not really an object" — like the bright spot of the laser pointer — "or infinite energy." In other words, cheats.

In the lab, researchers can create the impression of sending light faster than the speed limit by tweaking the speed at which the wave crests of light propagate through space. This, however, does not increase the speed at which the actual electromagnetic information travels — this is conveyed by the overall shape of the wave's amplitude.

Iron clad theory?

Since Einstein introduced special relativity, the theory and the special status it gives to the speed of light have appeared iron-clad.

Until now, that is. Scientists working on the OPERA experiment at the CERN laboratory in Switzerland beamed neutrinos 454 miles (730 kilometers) underground to Italy, and calculated how fast they made the trip. Shockingly, the neutrinos appeared to beat light speed by 60 billionths of a second. The finding appears to fly in the face of the last 106 years of physics.

"Our understanding hasn't evolved at all, we've been doing extremely precise tests of special relativity since the very first days," said Ben Monreal, an assistant professor of physics at University of California, Santa Barbara. "Special relativity has been passing tests with flying colors for over 100 years now. That is why this result is so surprising and unexpected."

If the finding of the OPERA experiment does pan out, the implications are much more mind-bending. Under special relativity, if something travels faster than the speed of light, it goes backwards in time. Such a proposition could interfere with the basic rule that cause precedes effect, called causality.

"The reason a lot of physicists are very unmoved by these claims is that it could make causality itself very problematic," Galison said. In other words, it raises the prospect of time travel.

There is another issue too. Einstein introduced the speed of light as a mathematical constant, c. If neutrinos can indeed exceed the speed of light, then c loses its special status, giving rise to a host of other problems elsewhere in physics, where c has been used in calculations, such as the famous formula E=mc^2.

"For all of these reasons, people are going to need extra evidence to conclude that it is going to hold up," Galison said.

Now let's understand this "Light Travels Backward and Faster than Light"

Robert Boyd, professor of optics stated this. It sounds nuts, but a scientist says his team has made light go backward. And this is not a simple trick of mirrors.

Previous work has slowed light to a crawl. But in the new research, a pulse of light is given a negative speed and—as if just to make your head spin—the researcher says the experiment made light appear to exceed its theoretical speed limit.

If you totally confused, don't worry. This reporter doesn't get it either. Nor do a lot of really smart scientists. "I've had some of the world's experts scratching their heads over this one," says Robert Boyd, a professor of optics at the University of Rochester. "It's weird stuff."

The research was reported in the May 12 issue of the journal Science. Though not normally stated in news reports, Science is a peer-reviewed journal. That means some experts read Boyd's paper and said it was good to publish.

That said, nobody would blame you if you stop here. Otherwise, grab a couple aspirin, have a look at depictions of the experiment and read on the internet.

If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second.

But if you are matter, then it's another matter altogether. (This is a good one you can have a smile or two).

Nothing we know of zips along more quickly than light. Einstein, nearly 106 years ago, said it's not possible. For us, the speed limit makes strange sense: Go faster than light, and you could return before you've left, become your own grandpa, or perform other leaps of cosmic logic. We're going to let Boyd do the explaining. And this next sentence is the crux of it all:

"We sent a pulse through an optical fiber, and before its peak even entered the fiber, it was exiting the other end. Through experiments we were able to see that the pulse inside the fiber was actually moving backward, linking the input and output pulses."

"The pulse of light is shaped like a hump with a peak and long leading and trailing edges. The leading edge carries with it all the information about the pulse and enters the fiber first. By the time the peak enters the fiber, the leading edge is already well ahead, exiting. From the information in that leading edge, the fiber essentially 'reconstructs' the pulse at the far end, sending one version out the fiber, and another backward toward the beginning of the fiber." Faster than light

Let's put that another way, verbatim from a statement issued by the University of Rochester:

"As the pulse enters the material, a second pulse appears on the far end of the fiber and flows backward. The reversed pulse not only propagates backward, but it releases a forward pulse out the far end of the fiber. In this way, the pulse that enters the front of the fiber appears out the end almost instantly, apparently traveling faster than the regular speed of light."

What about Einstein, who said nothing can exceed light-speed?

"Einstein said information can't travel faster than light, and in this case, as with all fast-light experiments, no information is truly moving faster than light," Boyd said.

A spokesperson at the university's communications department added this: "Everything that defines the pulse that enters, also defines the pulse that exits. But the energy of the light does not travel faster than light."

Fast forward a century. Astronomers are now measuring stuff -- material, matter, things -- that moves at so close to the speed of light you might think it'd make Einstein a bit nervous. His theory of relativity appears not to be endangered by the blazing speeds, though.

Among thee speed demons of the universe are Jupiter-sized blobs of hot gas embedded in streams of material ejected from hyperactive galaxies known as blazars. Last week at a meeting of the American Astronomical Society, scientists announced they had measured blobs in blazar jets screaming through space at 99.9 percent of light-speed.

"This tells us that the physical processes at the cores of these galaxies ... are extremely energetic and are capable of propelling matter very close to the absolute cosmic speed limit," said Glenn Piner of Whittier College in Whittier, California.

Ponder the power of the fast moving superheated gas, known as plasma:"To accelerate a bowling ball to the speed newly measured in these blazars would require all the energy produced in the world for an entire week," Piner said. "And the blobs of plasma in these jets are at least as massive as a large planet." The blazar jets are running around the universe in some fast company. Slightly faster, in fact.

In another study presented at the meeting, ultra high-energy cosmic rays thought to originate in a collision of galaxy clusters are slamming into Earth's atmosphere at more than 99.9 percent of the speed of light. Measurements put the number at 99.9 followed by 19 more nines -- about as close to light-speed as you can get without splitting hairs.

The particles are not light, but actual matter. They are tiny, thought to be mostly protons, but the energy that motivates them is similarly fantastic, and the mechanisms may be intertwined.

Scientists still don't know the exact mechanisms involved in accelerating matter to such high speeds, however. In the case of a blazars, it appears a black hole is involved. Anchoring an active galaxy, a supermassive black hole draws gas inward. Some is swallowed, yet some is simply accelerated and then ejected in high-speed jets along the galaxy's axis of rotation. Intense, twisted magnetic fields may play a role. Some ultra high-energy cosmic rays might originate in blazar jets, Piner told SPACE.com. But other phenomena may serve as particle accelerators in space, such as merging galaxies or colliding black holes.

Piner and his colleagues observed three blazars, known from previous observations to be super speedy, using the National Science Foundation's Very Long Baseline Array radio observatory. The results confirm the previous work and pin down the speeds with greater accuracy. The phenomenal pace of the plasma blobs looks to have reached a limit.

"All the results from blazar jet observations are in agreement with Einstein's Theory of Special Relativity," Piner said. "The jets are accelerated right up to the edge of the speed-of-light barrier but not beyond, even though these are some of the most efficient accelerators in the universe."

See now we are fighting to believe could we one day travel faster than light ? This is matter got .... Have great one. Feedbacks are welcomed.