Topic: Einstein's cosmic speed limit still reigns, for now
mightymoe's photo
Tue 07/30/13 01:39 PM
Clara Moskowitz
LiveSciene
Mon, 29 Jul 2013 15:41 CDT

© Iscatel/Shutterstock


Einstein's theory of special relativity sets of the speed of light, 186,000 miles per second (300 million meters per second). But some scientists are exploring the possibility that this cosmic speed limit changes.
The speed of light is considered to be the ultimate cosmic speed limit, thanks to Einstein's special theory of relativity. But physicists aren't content to assume this limit without testing it.

That's where a new experiment with electrons comes in. Physicists measured the energy required to change the speed of electrons as they hopped from one orbital to another inside atoms of dysprosium, all while Earth rotated over a 12-hour period. This allowed the scientists to measure that the maximum speed of an electron, which, according to special relativity should be the speed of light, is the same in all directions to within 17 nanometers per second. This measurement was 10 times more precise than previous tests of electrons' maximum speed.

So far, Einstein still comes out on top, and the theory holds. But the researchers hope to follow up the experiment with a more precise trial that might prove capable of poking holes in special relativity. That could actually be a good thing, scientists say, at least in terms of the advancement of physics.

"As a physicist, I want to know how the world works, and right now our best models of how the world works - the Standard Model of particle physics and Einstein's theory of general relativity - don't fit together at high energies," physicist Michael Hohensee of the University of California, Berkeley, said in a statement. "By finding points of breakage in the models, we can start to improve these theories."

The next iteration of the experiment should be up to a thousand times more sensitive, which may prove powerful enough to finally discover deviations from the predictions of special relativity, potentially pointing the way toward a more sophisticated theory that can resolve some of the current mysteries of physics.

"This technique will open the door to studying a whole other set of parameters that could be even more interesting and important," Dmitry Budker, another physicist at the University of California, Berkeley, said in a statement.

While similar questions about the speed of light could be investigated by high-powered experiments like the huge atom smasher in Switzerland, the Large Hadron Collider (LHC), the electron experiment here was relatively simple and inexpensive.

"You can try to probe these theories using big accelerators, but you would need to produce electrons with seven times the energy of the protons at the LHC," Hohensee said. "Or you can look at high-energy phenomena in distant stars or black holes, but those are not in the lab and not fully understood. Instead, we can look for evidence that the standard model or general relativity break at low-energy scales in small ways in a tabletop experiment."

The research will be published in an upcoming issue of the journal Physical Review Letters.

no photo
Tue 07/30/13 03:09 PM
Edited by Unknow on Tue 07/30/13 03:37 PM
I would love for them to find some anomalies in the new test.

Sorry to be pedantic though the electrons maximum speed cannot be the speed of light because they have mass (even though it is very very small, the mass increases the closer it gets to the speed of light). They can go 99.999999% the speed of light or something close to that (with today's currently powered particle accelerators)

mightymoe's photo
Tue 07/30/13 03:34 PM

I would love for them to find some anomalies in the new test.

Sorry to be pedantic though the electrons maximum speed cannot be the speed of light because they have mass (even thought it is very very small, the mass increases the closer it gets to the speed of light). They can go 99.999999% the speed of light or something close to that.


if electrons cannot exceed the speed of light, then isn't what they're doing pointless?

no photo
Tue 07/30/13 03:36 PM
Edited by Unknow on Tue 07/30/13 03:36 PM
Exceed? How is it pointless?

mightymoe's photo
Tue 07/30/13 03:44 PM

Exceed? How is it pointless?


i thought they were trying to go faster than light, but it looks like they are looking for fluctuations in the speed...

metalwing's photo
Tue 07/30/13 04:01 PM
What they are doing is trying to refine the absolute speed of light as pertains to an electron. Since the electron has mass, it may never be able to reach the speed of a light particle (photon) but under certain conditions, it might change a little. What they are measuring is the speed of jumping inside the electron shell from one "orbit" to another. This measurement, as indicated, is quite accurate without needing heavy equipment.

When an electron jumps orbit and spits out a photon, it moves to the next lower energy orbit as fast as it can. They are testing how fast it can move.

incagrass's photo
Wed 07/31/13 12:48 PM
Well if the speed of light's damn quick how come it takes me an hour to find my flashlight when a fuse blows? rofl

mightymoe's photo
Wed 07/31/13 12:54 PM

What they are doing is trying to refine the absolute speed of light as pertains to an electron. Since the electron has mass, it may never be able to reach the speed of a light particle (photon) but under certain conditions, it might change a little. What they are measuring is the speed of jumping inside the electron shell from one "orbit" to another. This measurement, as indicated, is quite accurate without needing heavy equipment.

When an electron jumps orbit and spits out a photon, it moves to the next lower energy orbit as fast as it can. They are testing how fast it can move.


how do they get the exact speed of light if the electrons don't travel that fast?

Traumer's photo
Tue 09/03/13 11:32 AM

Clara Moskowitz
LiveSciene
Mon, 29 Jul 2013 15:41 CDT

© Iscatel/Shutterstock


Einstein's theory of special relativity sets of the speed of light, 186,000 miles per second (300 million meters per second). But some scientists are exploring the possibility that this cosmic speed limit changes.
The speed of light is considered to be the ultimate cosmic speed limit, thanks to Einstein's special theory of relativity. But physicists aren't content to assume this limit without testing it.

That's where a new experiment with electrons comes in. Physicists measured the energy required to change the speed of electrons as they hopped from one orbital to another inside atoms of dysprosium, all while Earth rotated over a 12-hour period. This allowed the scientists to measure that the maximum speed of an electron, which, according to special relativity should be the speed of light, is the same in all directions to within 17 nanometers per second. This measurement was 10 times more precise than previous tests of electrons' maximum speed.

So far, Einstein still comes out on top, and the theory holds. But the researchers hope to follow up the experiment with a more precise trial that might prove capable of poking holes in special relativity. That could actually be a good thing, scientists say, at least in terms of the advancement of physics.

"As a physicist, I want to know how the world works, and right now our best models of how the world works - the Standard Model of particle physics and Einstein's theory of general relativity - don't fit together at high energies," physicist Michael Hohensee of the University of California, Berkeley, said in a statement. "By finding points of breakage in the models, we can start to improve these theories."

The next iteration of the experiment should be up to a thousand times more sensitive, which may prove powerful enough to finally discover deviations from the predictions of special relativity, potentially pointing the way toward a more sophisticated theory that can resolve some of the current mysteries of physics.

"This technique will open the door to studying a whole other set of parameters that could be even more interesting and important," Dmitry Budker, another physicist at the University of California, Berkeley, said in a statement.

While similar questions about the speed of light could be investigated by high-powered experiments like the huge atom smasher in Switzerland, the Large Hadron Collider (LHC), the electron experiment here was relatively simple and inexpensive.

"You can try to probe these theories using big accelerators, but you would need to produce electrons with seven times the energy of the protons at the LHC," Hohensee said. "Or you can look at high-energy phenomena in distant stars or black holes, but those are not in the lab and not fully understood. Instead, we can look for evidence that the standard model or general relativity break at low-energy scales in small ways in a tabletop experiment."

The research will be published in an upcoming issue of the journal Physical Review Letters.




The world of physics is a quirky, fickle field where very large ideas about the nature of time and space and even our human place in it seem to be under constant reconsideration; the harried physicist could always depend one one constant: the speed of light, The theory being that when light travels through a vacuum, its speed NEVER changes. At 186,000 miles per hour, to be precise, light holds the top speed for any and everything in the universe...well, not really.
In fact, no more.
Recent experiments, suggest that the speed of light is no longer sacred. As far back as 1999, a US team of physicists slowed light to a turtle paced speed of 38 miles per hour. Then, in the July 10, 2000 issue of Nature Magazine, other scientists reported having urged their light speeds forward, speeding up the light pulses to exceed the cosmic limit. They accomplished this by encouraging pulses to travel in a bunch; a group; this gave them a "group" velocity, rendering the whole greater than the sum of its parts. Together, the bunched groups of pulses could and did go over the speed limit set by Einstein, even if none of the individual light pulses could.
The major news implied; showed in this finding is that when the speed of light is exceeded even by a factor of 1/300, the light appears to travel backward in time. Einstein's brain may be twitching, the foundations of basic physics are not yet quaking. The experiments did not violate any of the established physical laws of nature, but they do show that it is now possible to manipulate light and possibly Time in ways to astonish scientists in most fields. For exact details of the experiments, see the July 10th, 2000 issue of Nature Magazine.