Can the speed of light be considered infinite?

[Milkman95]

<< I was too lazy to read the entire thread, but the light speed barrier HAS been broken. This happened in July of last year.
>>


Here is the end of the article (minus conclusion.. make your own!

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In Wang?s experiment, a pulse of light passed through a small chamber filled with atoms of elemental cesium. A light beam traveling through such a medium has two different velocities ? a velocity for the individual light waves in the beam and a group velocity for the entire beam. Oddly, some light waves in the beam can actually travel backward for miniscule amounts of time, creating a sort of "tail" behind forward-moving waves. As such, a light wave and its tail can leave the gas cavity at different times, creating the effect that the light beam has left the cavity before it?s even entered.

Confused? You?re not alone. In fact, even scientists who are familiar with this area of study are unsure about the details of Wang?s experiment. And many scientists said the experiment?s results are still open to interpretation.

William Happer, a physicist at Princeton University argued that several specific problems exist with the experiment, including the fact that pulses get distorted when passed through any media other than a vacuum, or empty space. In addition, he said Wang and his colleagues performed the experiment in a way that doesn?t tell the whole story, and that it can be interpreted incorrectly. "This is anything but dramatic," said Happer. "If you look at the data, there?s essentially no evidence that [the beam] is going faster than the speed of light."
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[khtm]

It seems that scientists opinions are divided on this matter. I have a friend who had a co-op job at the particle accelerator in Stanford and he seemed to think it was entirely possible. Myself, I don't know what to believe, but it sounds reasonable.



<< "It sounds crazy, but this can actually occur," said Raymond Chiao, a physicist at the University of California at Berkeley. Chiao, one of a group of researchers who have been working to break the speed-of-light limit, explained that although a common object such as a baseball could never be flung faster than the speed of light, pulses of energy with certain complex properties have been known to bend the rules. >>

 

[Looney]

You know, there's a reason why string theory didn't make it and was replaced by super string theory, which does not require these mysterious tachyon particles

An excellent book on superstring theory, and that is geared towards the layman, is Briane Greene's book The Elegant Universe.

 

[Harvey]

Wait a second (or a year)... If the speed of light is infinite, then a light year would be infinitely short. It isn't. Furthermore, light is electromagnetic radiation. If other forms of electromagnetic radiation (radio, microwave, etc.) also travel at the speed of light, there would be no delay in satellite communications. There obviously is, so I guess that settles the question.

 

[HomeBrewerDude]

lets try builing something that can go half the speed of light and see what happens when we send it to a neighboring star system.

 

[TheBullGod]

<<

<< nothing is faster than the speed of me.

sorry i just had to say that... bump! >>



You are wrong. According to Stephen Hawking's theories, certain paticles (I forget which) can travel faster than the speed of light at the event horizon of a black hole. As was said earlier by Elledan we don't know for sure around black holes.

amish >>



Yeah, I think I've heard of that too. Some kind of emissions from the event horizon.

 

[Harvey]

Just remember, next time you're thinking of doing something stupid the road, Nothing outruns a speeding Motorola! :Q

 

[Sir Fredrick]

Those of you who are really interested in this stuff should check out www.physicsforums.com
I don't hang out there regularly, but they're constantly debating about just this sort of thing, and they've got some really smart people over there. I won't link it in case it's considered to be competing with anandtech forums.

 

[Atlantean]

No, there are ways to go faster than light, well at least to cover a greater distance in a shorter time period. Also scientists have found a way to slow light to like 2 or 3 m/s something really slow like that, so I am sure that there are ways to make it go faster.

 

[Elledan]

<< Those of you who are really interested in this stuff should check out www.physicsforums.com
I don't hang out there regularly, but they're constantly debating about just this sort of thing, and they've got some really smart people over there. I won't link it in case it's considered to be competing with anandtech forums. >>


Heh, I was just about to bring up the same thing

I frequent physicsforums.com as well =)

 

[Elledan]

<< No, there are ways to go faster than light, well at least to cover a greater distance in a shorter time period. Also scientists have found a way to slow light to like 2 or 3 m/s something really slow like that, so I am sure that there are ways to make it go faster. >>


Your logic eludes me.

it's true that light can slow down, we can observe this when light has to travel through a non-vacuum. Yet have we ever observed light increase its speed when entering a certain substance or something?

 

[Nemesis77]

Not entirely related to the subject but... When Stephen Hawking was touring the set of "Star Trek: The Next Generation" (he performed his guest appearance in the show at that time), he was showed the Warp Core of the Enterprise. He looked at it and said "I'm working on that" .

He also revealed that one of his dreams is to sit in the captains chair of USS Enterprise. That dream was promptly fulfilled.

 

[Elledan]

<< You know, there's a reason why string theory didn't make it and was replaced by super string theory, which does not require these mysterious tachyon particles

An excellent book on superstring theory, and that is geared towards the layman, is Briane Greene's book The Elegant Universe. >>


I've never been able to appreciate books which try to simplify something which is in fact rather complicated. If I buy a book on something, I expect it to contain everything, up to the most obscure details, on that particular topic.

So... any books anyone here wants to recommend?

 

[Nemesis77]

Not related to the subject, but it seems that all the brainiacs hang out in this thread. Does anyone know anything about the phenomena where the results of earlier thest affect the following tests? I remember hearing about that few years ago. Some scientists were doing experiments with some particles, and they found out that the results of their previous tests, affected the results of following tests.

Not a good description, but that's the best way I can describe it . The theory seemed really wild, and it intrigued me.

 

[zzzz]

<< What we call 'time' is a mere perception >>


What about "newsweek" ?

 

[Elledan]

<< Not entirely related to the subject but... When Stephen Hawking was touring the set of "Star Trek: The Next Generation" (he performed his guest appearance in the show at that time), he was showed the Warp Core of the Enterprise. He looked at it and said "I'm working on that" >>


I saw that episode (I've seen every single episode, to be precise ). Pretty funny, actually

It's true that many scientists are working on a working model of a 'warp-drive'.

BTW, the designs of the spaceships in Star Trek are all wrong they all have the part of the warp-drive which generates the field located in two or four parts of the ship, while it would be much more effecient to place these units all around the ship's outer hull, to save energy (the field doesn't have to be that large) and make it more reliable (a larger field more easily generates errors in its structure).

 

[Beattie]

t = t0 / sqrt(1-(v^2 / c^2) )

the faster you go the slower your clocks are to outside observers

 

[Beattie]

<<
The way I've always understood it (I'd like to know if I'm wrong), is that it would be impossible for someone to go at the full speed of light, because at that point, they would be infinitely massive...
>>



It's not that it becomes infinitly massive, its because it takes in infinite amout of energy to accelerate something from .99c or less to 1c

 

[Nemesis77]

<< BTW, the designs of the spaceships in Star Trek are all wrong >>



Actually, US military has studied the design of the bridge of USS Enterprise (The TNG-model) as an example of excellent design. So don't be surprised if the bridges of future warships look like the bridge of USS Enterprise



<< they all have the part of the warp-drive which generates the field located in two or four parts of the ship, while it would be much more effecient to place these units all around the ship's outer hull, to save energy (the field doesn't have to be that large) and make it more reliable (a larger field more easily generates errors in its structure). >>



While that might be true, it might cause problems with the other systems of the ship. For example, shield-generators and such. To my knowledge, each nacelle (I'm using the term loosely here) generates one half of the warp-field around the ship (half-circle). Having two additional nacelles in front and back of the ship might make it more difficult to form a good warp-field. And having even more nacelles all around the ship would cause maintenance nightmare. And it would be even more difficult to control the field. Instead of two nacelles to take care of, you would have dozens. And of course more nacelles = more propable that something goes wrong.

OK, this is getting REALLY off-topic now!

 

[Elledan]

<< << they all have the part of the warp-drive which generates the field located in two or four parts of the ship, while it would be much more effecient to place these units all around the ship's outer hull, to save energy (the field doesn't have to be that large) and make it more reliable (a larger field more easily generates errors in its structure). >>



While that might be true, it might cause problems with the other systems of the ship. For example, shield-generators and such. To my knowledge, each nacelle (I'm using the term loosely here) generates one half of the warp-field around the ship (half-circle). Having two additional nacelles in front and back of the ship might make it more difficult to form a good warp-field. And having even more nacelles all around the ship would cause maintenance nightmare. And it would be even more difficult to control the field. Instead of two nacelles to take care of, you would have dozens. And of course more nacelles = more propable that something goes wrong. >>


Well, with the two (or four) nacelles placed behind the ship, the field has to be much larger than is necessary to surround the ship. I don't see how it would affect shield-generators either, or any other systems, for that matter.

Also, more nacelles == greater redundancy. If one fails, you've got a bunch more to take things over. According to your logic, a computer would be more reliable with less HD's and absolutely no RAID or tape-drive

 

[Nemesis77]

<< Well, with the two (or four) nacelles placed behind the ship, the field has to be much larger than is necessary to surround the ship. I don't see how it would affect shield-generators either, or any other systems, for that matter.

Also, more nacelles == greater redundancy. If one fails, you've got a bunch more to take things over. According to your logic, a computer would be more reliable with less HD's and absolutely no RAID or tape-drive >>



True, but maintenance of those nacelles would be extremely difficult. The savings you would get by having slightly more optimal warp-field would be lost to the additional cost of those extra nacelles and the recources it takes to maintain them. Also, the energy-consumption COULD be higher. Instead of having two powerful nacelles, you would have few dozen smaller nacelles. It could be that using those smaller nacelles to generate warp-field would take more energy that generating slightly bigger ward-field using just two nacelles.

And while having several nacelles would increase redundancy, it would also make the overall design much more complex. More complexity = more maintenance = more problems. In the end, increasing the number of nacelles becomes too costly when looking at the gains. I think having 2-4 nacelles is a nice balance between redundancy and simplicity.

 

[Tomek]

<< Tomek, actually if gravity does have a speed that is possible to measure then by definition it would not be instantaneous action. There are folks that also believ that the speed of light (and of gravity) is actually slowing with the expasion of the universe (theory now and fanciful at that but possible) and that at one time light actually traveled much faster than it does today (say a few seconds after the big bang). >>



Actually according to Hawking and Penrose's theorem (1970 I think) the big bang was the result of a singularity, which might not be governed by the normal laws of physics... that's why the initial expansion of the universe from the big bang was so incredibly fast.




<< If other forms of electromagnetic radiation (radio, microwave, etc.) also travel at the speed of light, there would be no delay in satellite communications. There obviously is, so I guess that settles the question. >>



Light is electronmagnetic (EM) radiation, any EM wave travels at c in vacuum... However, the delay in satellite communications is caused by electronic equipment and algorithms that we use the encode/decode the signal.




<< You are wrong. According to Stephen Hawking's theories, certain paticles (I forget which) can travel faster than the speed of light at the event horizon of a black hole. As was said earlier by Elledan we don't know for sure around black holes.
amish >>
Yeah, I think I've heard of that too. Some kind of emissions from the event horizon. >>




This emission from the event horizon is called Hawking radiation... It's caused by quantum effects. I'll give some more detail. Hang on for your life Quantum mechanics tells us that nothing, not even vacuum, has zero energy, the average energy of vacuum is zero, however the instantaneous energy is not. Relativity tells us that we can interchange energy with matter, and vice versa. So, what can happen is that somewhere out in space (in a vacuum environment) you have fluctuations of energy and, since we can interchange energy with matter, there is a possibility of a particle-antiparticle pair (need this to keep the charges balanced) spawns out of this fluctuation of energy. Now, if this occurs on the edge of the event horizon, you might have one particle spawn inside the Schwarzschild radius and one outside it. So, one of the particles will plunge into the black hole, while the other will pick up energy from the rotation of the black hole (one of Penrose's theorems) and will eventually escape from the gravitational pull of the black hole. So, in this way black holes emit particles...

 

[Oscar1613]

speaking of warp drives and such... here is some semi-related freaky sh!t:Q

 

[BD2003]

<< Light is electronmagnetic (EM) radiation, any EM wave travels at c in vacuum... However, the delay in satellite communications is caused by electronic equipment and algorithms that we use the encode/decode the signal. >>



I thought at the orbit of 22,500 miles, there was a 200ms delay for the light to reach the satellite, and another 200ms back, having absolutely nothing to do with encoding/decoding. I'd imagine you could speed up the encoding/decoding, but the speed of light is going to be a barrier, and satellite communications can never be instantaneous by their very nature.

 

[silverpig]

Okay there's a few things here.

First of all, light does not "slow down" in different media. It only appears to. Photons always travel at c no matter what. The fact that it takes longer for a beam of light to travel through a metre of glass than a metre of vacuum does not mean that the photons have slowed down, but that they had to interact with the atoms in the glass. Say I go from A to B at 100 km/h and then go from A to C to B at 100 km/h in a second trip. It takes me longer to get to B the second time, but I didn't slow down.

As to the original question, it seems as though most people are missing the point. Let's say I get in a ship travelling at a very high velocity to a place that is 50 ly away. I make a round trip, and come back just over 100 years after leaving for my trip. Over 100 years has passed on earth, so to you people here, it seems as though I was travelling at a speed slightly slower than c. But, due to the time warping effects of relativistic travel, I think I've only been gone for 2 years, and have thus travelled 100 ly in 2 years = 50c. If you get close enough to light speed, it can seem as though it is nearly infinite, so long as you are the one travelling.