Photons May Emit Faster-Than-Light Particles, Physicists Suggest

[Buster's Uncle]

Photons May Emit Faster-Than-Light Particles, Physicists Suggest
LiveScience.com
Charles Choi, LiveScience Contributor  1 hour ago
 

Scientific projects such as the Planck mission, aimed at measuring the afterglow of the Big Bang, could potentially detect signs of the decay of photons.

 
The particles that make up light, photons, may live for at least 1 quintillion (1 billion multiplied by 1 billion) years, new research suggests.

If photons can die, they could give off particles that travel faster than light.

Many particles in nature decay over time. For instance, radioactive atoms are unstable, eventually breaking down into smaller particles and giving off energy as they do so.

Scientists generally assume photons do not break down, since they are thought to lack any mass with which to decay. However, while all measurements of photons currently suggest they have no mass, they might instead potentially have masses too small for current instruments to measure.

"How much do we actually know about photons?" asked particle physicist Julian Heeck at the Max Planck Institute for Nuclear Physics at Heidelberg, Germany. "They led to several revolutions in science, but their properties are still a puzzle."

The current upper limit for the mass of the photon is less than two-billionths of a billionth of a billionth of a billionth of a billionth of a billionth of a kilogram. This would make it about less than a billionth of a billionth of a billionth of the mass of a proton.

Based on the Standard Model of particle physics, which governs the realm of the very tiny, Heeck calculated that photons in the visible spectrum would live for at least 1 quintillion years.

The extraordinarily long lifetime Heeck calculated is an average. "There is the possibility that some photons — very few, though — have decayed," he said. (The universe is currently about 13.7 billion years old.) Scientific projects such as the Planck mission, aimed at measuring the afterglow of the Big Bang, could potentially detect signs of such decay, Heeck noted.

If photons do break down, the results of such decay must be even lighter particles, ones that would travel even faster than photons. Assuming photons have mass, "there is only one particle we know from the Standard Model of particle physics that might be even lighter — the lightest of the three neutrinos," Heeck said.

Neutrinos are ghostly particles that only very rarely interact with normal matter. Countless neutrinos rush through everyone on Earth every day with no effect.

"It might well be that the neutrino is lighter than the photon," Heeck said. In principle, each photon might decay into two of the lightest neutrinos.

"The lightest neutrino, being lighter than light, would then actually travel faster than photons," Heeck said.

The idea of neutrinos that move faster than photons would seem to violate the notion, based on Einstein's theory of relativity, that nothing can travel faster than light. However, this assumption is based on the idea of the photon not having any mass. Einstein's theory of relativity "just states that no particle can travel faster than a massless particle," Heeck said.

Intriguingly, the speed that photons travel at means their extraordinary life spans will pass by quickly from their perspective. Einstein's theory of relativity suggests when particles travel extraordinarily quickly, the fabric of space and time warps around them, meaning they experience time as passing more slowly than objects moving relatively slowly. This means that if photons live for 1 quintillion years, from their perspective, they will only live about three years.

Heeck detailed his findings online July 11 in the journal Physical Review Letters.

http://news.yahoo.com/photons-may-emit-faster-light-particles-physicists-suggest-162013890.html

I gather that if lightspeed and general relativity are true, this article is bull - no time would pass for a quintillion year-old photon, and mass would be impossible, q.e.d.  I suppose these physicists are questioning whether all that is absolute.

[BrianAdkins]

Photons May Emit Faster-Than-Light Particles, Physicists Suggest
LiveScience.com
Charles Choi, LiveScience Contributor  1 hour ago
 

Scientific projects such as the Planck mission, aimed at measuring the afterglow of the Big Bang, could potentially detect signs of the decay of photons.

 
The particles that make up light, photons, may live for at least 1 quintillion (1 billion multiplied by 1 billion) years, new research suggests.

If photons can die, they could give off particles that travel faster than light.

Many particles in nature decay over time. For instance, radioactive atoms are unstable, eventually breaking down into smaller particles and giving off energy as they do so.

Scientists generally assume photons do not break down, since they are thought to lack any mass with which to decay. However, while all measurements of photons currently suggest they have no mass, they might instead potentially have masses too small for current instruments to measure.

"How much do we actually know about photons?" asked particle physicist Julian Heeck at the Max Planck Institute for Nuclear Physics at Heidelberg, Germany. "They led to several revolutions in science, but their properties are still a puzzle."

The current upper limit for the mass of the photon is less than two-billionths of a billionth of a billionth of a billionth of a billionth of a billionth of a kilogram. This would make it about less than a billionth of a billionth of a billionth of the mass of a proton.

Based on the Standard Model of particle physics, which governs the realm of the very tiny, Heeck calculated that photons in the visible spectrum would live for at least 1 quintillion years.

The extraordinarily long lifetime Heeck calculated is an average. "There is the possibility that some photons — very few, though — have decayed," he said. (The universe is currently about 13.7 billion years old.) Scientific projects such as the Planck mission, aimed at measuring the afterglow of the Big Bang, could potentially detect signs of such decay, Heeck noted.

If photons do break down, the results of such decay must be even lighter particles, ones that would travel even faster than photons. Assuming photons have mass, "there is only one particle we know from the Standard Model of particle physics that might be even lighter — the lightest of the three neutrinos," Heeck said.

Neutrinos are ghostly particles that only very rarely interact with normal matter. Countless neutrinos rush through everyone on Earth every day with no effect.

"It might well be that the neutrino is lighter than the photon," Heeck said. In principle, each photon might decay into two of the lightest neutrinos.

"The lightest neutrino, being lighter than led light, would then actually travel faster than photons," Heeck said.

The idea of neutrinos that move faster than photons would seem to violate the notion, based on Einstein's theory of relativity, that nothing can travel faster than light. However, this assumption is based on the idea of the photon not having any mass. Einstein's theory of relativity "just states that no particle can travel faster than a massless particle," Heeck said.

Intriguingly, the speed that photons travel at means their extraordinary life spans will pass by quickly from their perspective. Einstein's theory of relativity suggests when particles travel extraordinarily quickly, the fabric of space and time warps around them, meaning they experience time as passing more slowly than objects moving relatively slowly. This means that if photons live for 1 quintillion years, from their perspective, they will only live about three years.

Heeck detailed his findings online July 11 in the journal Physical Review Letters.

http://news.yahoo.com/photons-may-emit-faster-light-particles-physicists-suggest-162013890.html

I gather that if lightspeed and general relativity are true, this article is bull - no time would pass for a quintillion year-old photon, and mass would be impossible, q.e.d.  I suppose these physicists are questioning whether all that is absolute.

it is very important research.. Plenty of research in going on photons and it will surely change world around us..

[Buster's Uncle]

How do you imagine that happening?

[Bertilak]

If this is true, then perhaps some tachyons would be released. (Tachyon's are a hypothetical particle that always move faster than the speed of light.)

[Geo]

The 'holy traveling faster then light grail' won't (at least IMO) happen by working on a particle with slighty less mass then a photon. It's not so because it has a lower mass, one suddenly have a way of traveling dozens of times speed of light.
Infact, IF such a particle exists, and a hyperspace theory based on it works, it might be nothing more then the hyper drive used by the space colony in Asimov's 'Nemesis' novel: an averaging out at just below or just above the speed of light.

[Fal]

Is it the speed of light that matters in Relativity, or does "c" actually represent the speed of a massless particle, which photons have been assumed to be?

[Buster's Uncle]

Also, motion relative to the average rest state of the universe warps space-time, yes?  Special relativity, the E=MC² stuff, has been supported by observational evidence - in fact, GPS stuff has to take it into account to be accurate.

So say you're accelerating your starship to half the speed of light and experiencing significant relativistic time dilation - how does the bookkeeping work?  The universe is expanding, with all of it moving relative to the rest and the furthest bits retreating, IIRC, at about half lightspeed.  Clearly, your ship isn't going to not experience time dilation because it's synched with the speed and direction of an area 13 billion light years away.  And if I suppose that correctly, the frame of reference for determining what's relative motion is a little more local. 

So question is, how local?  A light year?  More?  Less?  Is it possible to understand this without being able to follow Einstein's math?

[Fal]

I thought relativistic space-time dilation depended on acceleration (and gravity), not speed?

[Geo]

I thought relativistic space-time dilation depended on acceleration (and gravity), not speed?

AFAIK, it depends on the velocity of an object, not its acceleration.
You have to keep in mind that, at the Universe level, the higher the fraction of light your velocity is, the more mass your vehicle seems to have for the rest of the Universe.

Acceleration gives you the impression of increased mass at the local level, thus within and on your vehicle, nothing beyond that.

but all that is a layman's description. There might still be a devil in the detail I'm not aware of...

[Buster's Uncle]

Velocity is relative, thus my question about the bookkeeping/frame of reference.