Can something move faster than light?

[goku]

there is another reason for the resistance to increased acceleration beyond what we are able to achieve; one which I can not yet expand upon here.

atoms, radiation, photons? :evil:

[EWright]

atoms, radiation, photons? :evil:

 

 

Dude, comeon. Photons ARE light and thus travel at c. Radiation is generally light in the non-visible spectrum, including x-rays, gamma rays, etc., which thus travel at c (actually it includes visible light photons too). Other forms of radiation, particles such as nutrons, alpha particles, electrons, protons, travel close to the speed of light, but do not exceed it. Atoms are made up of these particles, and are what matter is made of, so they don't travel per se... well they do, but they travel as part of the matter they make up, or perhaps "flow" (ie, a gas through space) in their elementary form.

 

Thanks for playing tho, try again :eek:

[goku]

Dude, comeon. Photons ARE light and thus travel at c.

i ment if they are traveling toward you, which they would no matter what direction you travel.

[EWright]

i ment if they are traveling toward you, which they would no matter what direction you travel.

 

SR predicts that you will measure light to travel at the same constant speed of c no matter what... this includes if you're a traveling toward the source or away from the source at any speed, including .90c. That doesn't mean that SR is right, but that's what it predicts and all tests APPEAR to support SR.

[sergey500]

I don't need to think. I know there is something that moves faster than light...LIGHT IT SELF. Some time ago, i don't remember, if your interested i'll find something for you, a bunch scientist pushed a photon faster than it usual speed, thus going faster than light.

 

While i am on subject, Einstein said nothing can move faster than light. Ex: Your on train/plane and your moving at speed of light and you run/walk forward, your going faster than light. But einstein said it was impossible, when asked why, he would simply say because it isn't. Explain, anyone? (oh and please reply it in words anyone can understand, not advance mathamtical formulals)

[EWright]

I don't need to think. I know there is something that moves faster than light...LIGHT IT SELF. Some time ago, i don't remember, if your interested i'll find something for you, a bunch scientist pushed a photon faster than it usual speed, thus going faster than light.

 

While i am on subject, Einstein said nothing can move faster than light. Ex: Your on train/plane and your moving at speed of light and you run/walk forward, your going faster than light. But einstein said it was impossible, when asked why, he would simply say because it isn't. Explain, anyone? (oh and please reply it in words anyone can understand, not advance mathamtical formulals)

 

Quite simply because the circumstances you describe could not exist. Relativity PROHIBITS any object with mass from reaching light speed. This is because the theory says it would take an infinite amount of energy to accelerate an object to this speed. Furthermore, if you are traveling at a significant fraction of the speed of light, even towards the light source, you will measure the speed of light at the same rate no matter how fast you travel.

 

I believe I read something along the lines of the experiment you mentioned, in which a photon was pushed faster. I believe there was some questions surrounding it tho... Can you provide me a source or a link for that please?

[sergey500]

I am probably got my terms mixed, but photon, the light particle, is a massless particle, basicly it is energy with a shell. Ergo it can reach past the speed of light under whatever enviroment these scientist provided....Oh well i am sorry, i just got myself confused, i thought you were refering to the expirment (i started typing before i finished reading your post).

 

But wait, what would happen, supposibly (i used this expirment in a time travel example i set up once, nobody found anything wrong with it) an object, any object, it traveling at speed of light and it ends up in the only place in universe where laws don't apply, the black hole. Wouldn't the object (if it didn't break apart) being going faster there? Well specificly speaking its not the object that is giving off the energy, it would be the gravity off the black hole. And of course, i know what you mean, einstein descibed this in his special theory of relativity.

 

Link: http://news.bbc.co.uk/1/hi/sci/tech/781199.stm (read below the "Diffcult Experiments".

[EWright]

I am probably got my terms mixed, but photon, the light particle, is a massless particle, basicly it is energy with a shell. Ergo it can reach past the speed of light under whatever enviroment these scientist provided....Oh well i am sorry, i just got myself confused, i thought you were refering to the expirment (i started typing before i finished reading your post).

 

But wait, what would happen, supposibly (i used this expirment in a time travel example i set up once, nobody found anything wrong with it) an object, any object, it traveling at speed of light and it ends up in the only place in universe where laws don't apply, the black hole. Wouldn't the object (if it didn't break apart) being going faster there? Well specificly speaking its not the object that is giving off the energy, it would be the gravity off the black hole. And of course, i know what you mean, einstein descibed this in his special theory of relativity.

 

Link: http://news.bbc.co.uk/1/hi/sci/tech/781199.stm (read below the "Diffcult Experiments".

 

You can not make the argument that FTL is possible inside a BH, since know one understands the physics inside of one. And I believe relativity still dictates that no object with mass could travel faster that light even then. Besides, you'd probably be ripped apart into a form of energy rather than matter in the process.

[sergey500]

Well ripping apart we don't have to worry about, since i said, or thought i did, that the object is build of some sort of matter that won't break apart. I know we don't know much about black holes, but we won't get anywhere if we don't make assumptions. So that was my assumption. BH is best example because it only place in universe where the insanities of quantum mechanics can be safely put together with revetelity.

[CraigD]

…I believe I read something along the lines of the experiment you mentioned, in which a photon was pushed faster. I believe there was some questions surrounding it tho... Can you provide me a source or a link for that please?

No credible person, to my knowledge, has ever claimed to push an individual photon either faster of slower than the speed of light.

 

What Sergy and Ewright are likely recalling are one or several experiments such as the one described in this physicsweb article. Such experiments involve manipulating the various characteristics of a collection of photons (of different energies/wavelengths) that can be used to measure in various ways the speed of a pulse of light - group velocity, front velocity, and phase velocity. These measures are related in interesting ways. None of these experiments, however, suggest that an actual photon (to speak meaningfully, its quantum wave function with respect to time) can be made to travel at other than the speed of light.

 

This wikipedia article has a good discussion of various "’Faster-than-light’ observations and experiments”, including links to various wave velocity measurements.

[sergey500]

but craig, i provided a link, and i am sure the link gave credit to someone.

[EWright]

Well ripping apart we don't have to worry about, since i said, or thought i did, that the object is build of some sort of matter that won't break apart. I know we don't know much about black holes, but we won't get anywhere if we don't make assumptions. So that was my assumption. BH is best example because it only place in universe where the insanities of quantum mechanics can be safely put together with revetelity.

 

Serg, you can't simply make up assumptions with no basis and then challenge someone to prove them wrong from within a framework in which the laws of physics are not understood. I do agree with trying to push the envelope, and with presenting new and even unusual ideas, but if we want to present challenges in this way the possibilities are endless. And you can't just 'invent' matter that won't break apart. If you can do that, we can just invent a spaceship that travels faster than light, right here in normal space because it all takes place in our minds.

[madazn89]

how fast does electrons move?

madazn:hyper:

[CraigD]

but craig, i provided a link, and i am sure the link gave credit to someone.

You linked to a very well-written 7/7/2000 BBC news article, in which science editor Whitehouse credits separate research by Ranfagni and Wang. Since it was written, more similar research has been published, and appeared in many good journals, popular magazines, and websites.

 

It’s important to read the article carefully. Consider the following quotes from the BBC article (emphasis mine)

Physicists have been making light pulses that travel faster than c (the speed of light in a vacuum) for years.

The arrival times of these pulses showed that they travelled at speeds 5% above c.

According to the researchers, the main part of the light pulse leaves the far side of the chamber even before it enters at the near side!

The phrase “light pulse” and “main part of the light pulse” are clues that what’s being referred to is not an indivisible quantum of light – a photon – but something more complicated – a collection of many photons constituting a pulse of light. If one were to represent this pulse as a paper cutout (call it its “wave envelope”), and find its center of gravity, that would be the point you’d measure to get its group velocity (follow the link for wiki details). What these researchers are doing is cleverly causing the shape of the pulse’s wave envelope to suddenly change, so that the “main part” of the envelope where we measure the group velocity is moving faster or slower (sometimes so much slower that the group velocity is negative!) than c. No individual photon ever travels faster than c in these experiments, however, something researchers are careful to point out in their papers and when interviewed by science reporters.

 

You might find this analogy helpful:

We define the velocity of a ski lift to be the velocity that the center of gravity of 10 adjacent chairs, including occupants, are moving. The ski lift moves at a constant 2 m/s, and the chairs are 5 meters apart. Empty, the 10 chairs and their connecting cable weigh 500 kg, and can hold 2000 kg of skiers. It’s supported by pylons placed every 100 m.

 

With all 10 chairs loaded with 20 identical, 100 kg skiers, we measure the velocity at their center of gravity by timing low long it takes to pass each pylon – 50 seconds, giving the expected 2 m/s. Now, midway between 2 pylons, all of the skiers except the 2 in the front chairs jump out. The center of gravity of the 10 chairs with the 2 remaining skiers is now. The center of gravity suddenly changes to from between the 5th and 6th chairs to between the 3rd and 4th, a change of 15 meters. It reaches the next pole sooner than expected, in 42.5 seconds, giving a velocity slightly more than 2.35 m/s, 18% faster than the lift’s “c” of 2 m/s.

 

Note that neither the lift nor any of the skiers exceeded 2 m/s (for the sake of this example, let’s assume this is a weird lift with chairs facing backwards, so when they jumped out, the 18 skiers briefly moved slower, not faster than 2 m/s).

 

As in the light-pulse experiments, the increased “group velocity” doesn’t represent a change in either systems constant speed (2 m/s or about 3*10^8 m/s), but a manipulation of the “envelope” traveling at that constant speed.

[ldsoftwaresteve]

Physicists have been making light pulses that travel faster than c (the speed of light in a vacuum) for years.

Why don't you consider the possibility that photons are connected all the way back to the source of light and actually are particles? In his book, The Final Theory, McCutcheon proposes that advanced civilizations would not communicate with radio waves, rather they would communicate with light using the contiguous property mentioned in the quote - effectively having faster than light communications. Incidentally, he doesn't think there is a speed of light limitation on movement either.

[Tormod]

Why don't you consider the possibility that photons are connected all the way back to the source of light and actually are particles?

 

How does this work over, say, long distances? If for a second we assume that it is correct, how would such a signal cope with being blocked by, for example, a planet? If I were on the "wrong" side of Mars, could I still communicate with someone on Earth?

[Tormod]

how fast does electrons move?

madazn:hyper:

 

Electrons move at 99.9999992% of the speed of light according to this page:

 

http://education.jlab.org/qa/electron_01.html