Why is the speed of light our "speed limit"?

[PlasmaBomb]

Originally posted by: QuantumPion

Originally posted by: PlasmaBomb

Originally posted by: Shadow Conception
What if you turned on a laser on a spacecraft going 0.999c and shined it in the direction of the space shuttle's propulsion? Would this laser be going at (almost) 2c?

No.

PS. Photons aren't massless they just have zero inertial mass. There is a difference.

No.

Convention in the physics community is that "mass" means rest mass, inertial mass, invariant mass, etc. Relativistic mass is usually just called energy. You can be silly and say photons have mass all day long, referring to its relativistic mass, but in practice this is wrong.

In other words, the statement "photons aren't massless" is incorrect, because when talking about relativistic mass you have to explicitly say so, since just plain mass always refers to the invariant mass.

My mistake then sorry

 

[Anonymous1234]

Photons medium is the very basic fabric of space time in which everything we can observe and some things we can't lie in. Some think this fabric is also part or most of what makes up dark matter( the matter we know is out there but can't find). Most of this stuff is highly theoretical and has various explanations that are all right in different ways. A simple answer to your question is that if we were to approach or exceed the speed of light, we would essentially be forming a black hole and the matter doing this would for all intents and purposes disappear from our sight and possibly dimension. Another way to look at it is that This can be thought of as a very heavy marble rolling to the middle of a tissue and then falling through the center since it can no longer support its weight. Also another way to think of it is like you have a sheet made out of a near impenetrable rubber band. Its elasticity will start to bend it down under the pressure and, if enough pressure is applied to a small enough spot, it will essentially be a deep depression, and ,at that point, you wouldn't be able to see the object making the hole, just the hole itself and everything around the hole would be normal up to the hole itself. Possibly another explanation of the speed of light is that this is the natural resistance of our universe and at a point when u approach it, you can break through the medium your traveling through. There are very complex theories trying to describe all this and form a theory of everything. Some promising ones atm are variations of string theory, Superstrings, Bosonic string theory, and
M-theory which attempts to unify them. String theories include objects more general than strings, called branes. These are black-holes charged with a differential form vector potential which has more than one index, a different type of electricity and magnetism where the fundamental objects are extended(wikipedia). Its all mind bogling i know. Taking physics classes up to quantum and higher will help you understand this.

Take everything on forums with a grain of salt. Even though these forms seem generally to have more intelligent people than most.

 

[Foxery]

Originally posted by: Anonymous1234
...

Take everything on forums with a grain of salt. Even though these forms seem generally to have more intelligent people than most.

Dear god, my eyes! Please take an English class before commenting on our intelligence level.

The OP pretty much had his answer 2 weeks ago, though. This was a particularly good point:

Originally posted by: KIAman
The simplest answer to the OP's questions is that light is the fastest form of information transfer.

So, until we have a faster medium of information transfer, light, simply by our definition of information, is the cosmic speed limit.

i.e. We only have the ability to observe things using light, and therefore can't observe anything which moves faster. If there is any aspect to the Universe beyond this, we haven't discovered it yet.

 

[Aberforth]

Light isn't the fastest, light can bend in a electro magnetic field (which makes the source object invisible), in fact the whole universe is one big electro magnet and that's how the shape of a galaxy can be recognized, there is a very strong Electromagnetism at the core of each galaxy.

end of story.

 

[Aberforth]

To travel faster than light the object has to achieve acceleration through EM spectrum path.

 

[KIAman]

Originally posted by: Aberforth
Light isn't the fastest, light can bend in a electro magnetic field (which makes the source object invisible), in fact the whole universe is one big electro magnet and that's how the shape of a galaxy can be recognized, there is a very strong Electromagnetism at the core of each galaxy.

end of story.

?

What are you blabbing about? Let me attempt to use some of your logic and see if you make sense.

Light isn't the fastest, light can bend in a gravitational field (...), in fact the whole universe is one big gravitational field ..., there is a very strong gravitational field at the core of each galaxy.

or

Light isn't the fastest, stuff can bend light (like glass, water, rocks, etc.) in fact, the whole universe is one big stuff..., there is stuff at the core of each galaxy.

How do any of these correct statements lead to the fact that light isn't the fastest?

 

[HVAC]

I am going to blow your mind.

Things do travel faster than the speed of light. We just cannot perceive them because the fastest methods we have for detection are light based. Additionally, we cannot transfer the information that is carried at faster than light to a speed we can detect without losing information in the process.

We have to proverbially pull ourselves up by our bootstraps to be able to start detecting things traveling faster than the speed of light. And when that happens, our senses will still be unable to detect the speed or even the passage of particles at such a speed.

 

[Aberforth]

Originally posted by: KIAman

Originally posted by: Aberforth
Light isn't the fastest, light can bend in a electro magnetic field (which makes the source object invisible), in fact the whole universe is one big electro magnet and that's how the shape of a galaxy can be recognized, there is a very strong Electromagnetism at the core of each galaxy.

end of story.

?

What are you blabbing about? Let me attempt to use some of your logic and see if you make sense.

Light isn't the fastest, light can bend in a gravitational field (...), in fact the whole universe is one big gravitational field ..., there is a very strong gravitational field at the core of each galaxy.

or

Light isn't the fastest, stuff can bend light (like glass, water, rocks, etc.) in fact, the whole universe is one big stuff..., there is stuff at the core of each galaxy.

How do any of these correct statements lead to the fact that light isn't the fastest?

lol

In order to bend light the force acting on it must be faster than the light traveling in Vaccum, electromagnetism is the only force that can bend light, in a em field the electrons travel faster than light which is responsible for bending light. One such example is "Black-Holes" in the galaxy, it is so strong that it will suck all the light coming towards it an thanks to infrared telescopes and XRAY imaging invented by great people we are now able to analyze what exactly happens inside a backhole.

Look at Faraday's experiment as well. There is more to it.

 

[KIAman]

Bah, I can't believe I am humoring you with a response.

Let me show you how many wrong statements you have just made.

1. "In order to bend light... must be faster than light in Vaccum"
Examples of sub-luminal phenomena that bend light
a) glass
b) water

2. "electrons travel faster than light"
According to all laws of known physics, this is impossible

3. "black holes, example of electromagnetism bending light"
Although it is an interesting proposition for a science fiction novel to believe this but it is gravity which is bending light

4. "black holes are so strong, it will suck all incoming light"
A black hole's gravity is so strong as to warp the space enough for light to follow a path in orbit or toward the singularity

5. "infrared telescopes and xray machines to see inside blackholes"
There is no instrument available that can show us what happens inside of a black hole, all current theories rely on laws of physics and math

6. "Look at Faraday's experiment... in relation to em"
I'm very familiar with Faraday's Laws and field theory and I don't see any correlation to speed of something faster than light.

 

[Aberforth]

*yawn* Looks like I shouldn't bother explaining when other person's mind is so helplessy degenerated by looking into documented facts made by other people. It only brings dependence on the information of such kind...heck if i want to know what others did I'll look into my encyclopaedia.

thnx bye

 

[Nathelion]

Originally posted by: Aberforth
*yawn* Looks like I shouldn't bother explaining when other person's mind is so helplessy degenerated by looking into documented facts made by other people. It only brings dependence on the information of such kind...heck if i want to know what others did I'll look into my encyclopaedia.

thnx bye

Looks like we have a troll on our hands...

 

[Foxery]

Originally posted by: Aberforth
heck if i want to know what others did I'll look into my encyclopaedia.

Welcome to Highly Technical, where we don't use a Mad-Libs book to throw together funny sounding words. If you wish to troll aimlessly, Off Topic is this way.

 

[jALLAD]

lol

In order to bend light the force acting on it must be faster than the light traveling in Vaccum, electromagnetism is the only force that can bend light, in a em field the electrons travel faster than light which is responsible for bending light. One such example is "Black-Holes" in the galaxy, it is so strong that it will suck all the light coming towards it an thanks to infrared telescopes and XRAY imaging invented by great people we are now able to analyze what exactly happens inside a backhole.

Look at Faraday's experiment as well. There is more to it.

do you even have the faintest idea of the principles of Physics?
or mayb, you are just joking. in that case lol

 

[TuxDave]

nm...

 

[QuantumPion]

Originally posted by: Foxery

Originally posted by: Anonymous1234
...

Take everything on forums with a grain of salt. Even though these forms seem generally to have more intelligent people than most.

Dear god, my eyes! Please take an English class before commenting on our intelligence level.

The OP pretty much had his answer 2 weeks ago, though. This was a particularly good point:

Originally posted by: KIAman
The simplest answer to the OP's questions is that light is the fastest form of information transfer.

So, until we have a faster medium of information transfer, light, simply by our definition of information, is the cosmic speed limit.

i.e. We only have the ability to observe things using light, and therefore can't observe anything which moves faster. If there is any aspect to the Universe beyond this, we haven't discovered it yet.

I think a better explanation is this:

The laws of physics have proven to be true in any inertial reference frame. This means that if you are moving at 1 m/s or 1000000 m/s, in your reference frame the same laws of physics apply. This includes Maxwell's Equations. The speed of light is derived from certain variables of these equations. Therefore, the speed of light must be the same in any reference frame.

It's not that there is anything special about photons or light itself. But as a consequence of the speed of light being constant, in order for the laws of physics to be the same in any reference frame, the equation to describe the energy or speed of a particle will have an asymptote at the speed of light.

For example, the every-day equation for kinetic energy is E = 0.5*mv^2. This is really just an approximation though, which works fine when v << c. In relativistic terms, kinetic energy E = mc^2 / (1 - v^2/c^2) - m0c^2. As v becomes very large and approaches c, the denominater approaches 0. If v = c, then the energy would be a number divided by 0. if v > c, then the energy would be negative.

What does 1/0 or negative energy represent? As far as we know, nothing, it is a statement showing that math does not always relate to reality. When we get divive-by-zero's and infinities in equations of physical systems, we interpret that to mean that it is a situation that cannot occur in the real world.

So to answer the OP's question, the reason why nothing can go faster then light (except for massless particles, which MUST travel at the speed of light), is because the laws of physics are the same in all reference frames. It is a consequence of relativity.

 

[EricMartello]

Originally posted by: QuantumPion
So to answer the OP's question, the reason why nothing can go faster then light (except for massless particles, which MUST travel at the speed of light), is because the laws of physics are the same in all reference frames. It is a consequence of relativity.

Here is the real answer: nobody really knows because nobody has been able to travel at the speed of light (yet).

Physicists and scientists have accepted Einstein's famous e=mc^2 equation as fact, and therefore if something doesn't fit into the equation accepted by the majority, it is deemed as not possible. Aside from that, there is no inherent limitation on the ability of an object with mass to match or exceed the velocity of light within a vacuum.

There may be a "terminal universal velocity" for physical objects within this universe, but I'd wager that light does not represent THAT speed limit. Light represents a human limit that we have yet to conquer...before that it was sound.

 

[QuantumPion]

Originally posted by: EricMartello

Originally posted by: QuantumPion
So to answer the OP's question, the reason why nothing can go faster then light (except for massless particles, which MUST travel at the speed of light), is because the laws of physics are the same in all reference frames. It is a consequence of relativity.

Here is the real answer: nobody really knows because nobody has been able to travel at the speed of light (yet).

Physicists and scientists have accepted Einstein's famous e=mc^2 equation as fact, and therefore if something doesn't fit into the equation accepted by the majority, it is deemed as not possible. Aside from that, there is no inherent limitation on the ability of an object with mass to match or exceed the velocity of light within a vacuum.

There may be a "terminal universal velocity" for physical objects within this universe, but I'd wager that light does not represent THAT speed limit. Light represents a human limit that we have yet to conquer...before that it was sound.

No. You're flat-out completely 100% wrong in every possible respect.

We DO know why the speed of light is the universal speed limit, and I just explained why in my previous post.

Relativity has been proven experimentally. There hasn't been any instance where "something" didn't fit the equation. If "something" did, then scientists would have to figure out what was going on. However, as of yet there has been no such instance and our current understanding is that c is the limit.

There certainly IS an inherent limit on the ability of an object to match the speed of light. Light is not some made-up human limitation like the speed of sound was before Chuck Yeager. It is a fundamental property of nature.

 

[Foxery]

Originally posted by: EricMartello
Here is the real answer: nobody really knows because nobody has been able to travel at the speed of light (yet).

Physicists and scientists have accepted Einstein's famous e=mc^2 equation as fact

Wow, no. No. Did you even read the rest of the post?

Most of Physics is based on math, regardless of our ability to demonstrate the theories in a real experiment. No one has disproven Einstein's math in 70 years, but you are more than welcome to try.

 

[EricMartello]

Originally posted by: QuantumPion
No. You're flat-out completely 100% wrong in every possible respect.

We DO know why the speed of light is the universal speed limit, and I just explained why in my previous post.

Relativity has been proven experimentally. There hasn't been any instance where "something" didn't fit the equation. If "something" did, then scientists would have to figure out what was going on. However, as of yet there has been no such instance and our current understanding is that c is the limit.

There certainly IS an inherent limit on the ability of an object to match the speed of light. Light is not some made-up human limitation like the speed of sound was before Chuck Yeager. It is a fundamental property of nature.

Is it just "Relativity" now, or is it still the THEORY of Relativity? I mean, if it is now accepted as Einsteins Law's of Relativity, then yeah, I'm wrong...but I never received that memo.

Here's a quick fact - saying you understand something completely because you understand it mathematically (only) is like saying you know what sex is like because you've seen a lot of porn.

Until someone travels at the speed of light, we can only guess what happens...we have general ideas...but speculation is no substitute for good ol experience.

Anyway, I bolded the important part of your reply, which basically affirms my position. Thanks.

Originally posted by: Foxery
Wow, no. No. Did you even read the rest of the post?

Most of Physics is based on math, regardless of our ability to demonstrate the theories in a real experiment. No one has disproven Einstein's math in 70 years, but you are more than welcome to try.

I'm not arguing the basis of the math involved, we're talking about what REALLY happens if some person were able to travel at the speed of light. Our current theories are largely based on what we can observe...so there hasn't been anyone quite as creative as Einstein in all these years...we can't control that, but saying that something is true simply because it has not yet been disproven sounds almost as irrational as believing in fictitious deities who live in the sky. Sciligion?

We cannot disprove a theory that is based on something we're not yet able to test...but there will come a time when we can see for ourselves if the 'speed of light' is the mythic speed limit everyone thinks it to be. Until that time, I suppose most scientists are going to put their faith in Einstein's sacred theories. Amen.

 

[PolymerTim]

Originally posted by: EricMartello
We cannot disprove a theory that is based on something we're not yet able to test...but there will come a time when we can see for ourselves if the 'speed of light' is the mythic speed limit everyone thinks it to be. Until that time, I suppose most scientists are going to put their faith in Einstein's sacred theories. Amen.

Actually, there is plenty of experimental evidence that supports Relativity theory. I'm no expert, but you can do a little digging starting with wikipedia if you're curious.
http://en.wikipedia.org/wiki/S..._of_special_relativity
http://en.wikipedia.org/wiki/T..._of_general_relativity
http://en.wikipedia.org/wiki/G...ativity#Current_status

I think, at this point, you wouldn't argue so much the accuracy of the thoery as the completeness of it. If the wikipedia authors are correct, the theory still leaves plenty of room for expansion and additional effects. It is not a theory of everything; Einstein didn't quite get that far.

I believe that if we ever manage to make something go faster than light, it won't so much invalidate Einsteins theories as it will add to them. Every theory has its limitations and a new theory will probably need to work around the currently accepted ones and explain the circumstances where they no longer apply.

I am curious to know how you think the ultimate speed limit can be tested in the future. You seem to be working under the assumption that we will eventually go faster and that will be your proof that you can. But what if we never get that fast? Are you arguing that there is no way to prove a true limit?

 

[QuantumPion]

Originally posted by: PolymerTim

Originally posted by: EricMartello
We cannot disprove a theory that is based on something we're not yet able to test...but there will come a time when we can see for ourselves if the 'speed of light' is the mythic speed limit everyone thinks it to be. Until that time, I suppose most scientists are going to put their faith in Einstein's sacred theories. Amen.

Actually, there is plenty of experimental evidence that supports Relativity theory. I'm no expert, but you can do a little digging starting with wikipedia if you're curious.
http://en.wikipedia.org/wiki/S..._of_special_relativity
http://en.wikipedia.org/wiki/T..._of_general_relativity
http://en.wikipedia.org/wiki/G...ativity#Current_status

I think, at this point, you wouldn't argue so much the accuracy of the thoery as the completeness of it. If the wikipedia authors are correct, the theory still leaves plenty of room for expansion and additional effects. It is not a theory of everything; Einstein didn't quite get that far.

I believe that if we ever manage to make something go faster than light, it won't so much invalidate Einsteins theories as it will add to them. Every theory has its limitations and a new theory will probably need to work around the currently accepted ones and explain the circumstances where they no longer apply.

I am curious to know how you think the ultimate speed limit can be tested in the future. You seem to be working under the assumption that we will eventually go faster and that will be your proof that you can. But what if we never get that fast? Are you arguing that there is no way to prove a true limit?

What I got out of what Eric said was that we can't prove that you can't go faster then the speed of light until we go faster then the speed of light and see what happens.

Based on his attempt to disprove relativity by pointing out that it is called a "theory" and not a "law" (when he doesn't understand the distinction), and that he tries to discount scientists by likening them to having unquestioning faith in science, I'm guessing he's a kook. There's no use arguing with those types.

 

[drebo]

I don't know...maybe he has a point... By your own admission, the equations for kinetic energy can't explain what happens when v > c, and in fact the results don't make sense in that event (negative energy?). Maybe the equations and our understanding of the constants from which they were derived are incomplete.

Obviously, I'm not nearly qualified to make any kind of judgement on whether or not relativity is true, provable, or accurate, and I'm not entirely serious about my above statement.

Though it is kind of interesting to think about...I mean, I've never really bought in to the idea that just because you cannot observe time passing (going the same speed as the light) that time stops. If you go to the bottom of a cave where no light can get to, does everything outside the cave stop aging? To me, it seems like the same thing: you can't observe it, so it must not be happening.

 

[EricMartello]

Originally posted by: PolymerTim
Actually, there is plenty of experimental evidence that supports Relativity theory. I'm no expert, but you can do a little digging starting with wikipedia if you're curious.
http://en.wikipedia.org/wiki/S..._of_special_relativity
http://en.wikipedia.org/wiki/T..._of_general_relativity
http://en.wikipedia.org/wiki/G...ativity#Current_status

I think, at this point, you wouldn't argue so much the accuracy of the thoery as the completeness of it. If the wikipedia authors are correct, the theory still leaves plenty of room for expansion and additional effects. It is not a theory of everything; Einstein didn't quite get that far.

I believe that if we ever manage to make something go faster than light, it won't so much invalidate Einsteins theories as it will add to them. Every theory has its limitations and a new theory will probably need to work around the currently accepted ones and explain the circumstances where they no longer apply.

I am curious to know how you think the ultimate speed limit can be tested in the future. You seem to be working under the assumption that we will eventually go faster and that will be your proof that you can. But what if we never get that fast? Are you arguing that there is no way to prove a true limit?

I'm aware of Einstein's theories, and yeah, you're right. Theories do leave room for expansion...which is why people who misrepresent them as absolute facts are in error.

What I am saying is that we can speculate all we want about what happens to us IF we could move at the speed of light. It's being passed off as an impossibility or "speed limit", but the fact of the matter is, we won't know for sure until we do and I think it's better to leave it at that for now instead of pretending to understand it wholly, when we only know a small part. What if we never travel at light speed or faster? In that case I guess STR will be valid for another 70 years or so.

Einstein basically decided that light speed (in a vacuum) is the glue for "spacetime", and it is not possible to match or exceed light speed because of "infinite energy requirements". I dunno, for a guy who probably never moved more than 200 MPH...that's a lot of speculation. It's also hinging on the notion that TIME actually exists, and that TIME is not a human perceptual limitation.

Just out of curiousity, why look for limits? Has anyone ever tried reworking accepted physics equations and excluding time altogether? That would mean that things like "distance" and "velocity" don't exist anymore...but hey, why not try it? Something that is a limitation to us as humans isn't necessarily a universal limitation.

Originally posted by: QuantumPion
What I got out of what Eric said was that we can't prove that you can't go faster then the speed of light until we go faster then the speed of light and see what happens.

Based on his attempt to disprove relativity by pointing out that it is called a "theory" and not a "law" (when he doesn't understand the distinction), and that he tries to discount scientists by likening them to having unquestioning faith in science, I'm guessing he's a kook. There's no use arguing with those types.

Ah, I'm not trying to disprove anything. I'm merely stating that there is no definitive answer, and I am saying that a theory is just that - a theory. My first answer to the OP is still the same: WE DON'T KNOW! But it sure is fun to guess, right? I am sure that stuff that we don't know does matter, but going all religious zealot and "putting faith in theories" when you're working with science is not the way to make progress. Einstein set the limits for his theories, and since we have not been able to test any of those limits, it's only logical that - to date - his theories "check out".

 

[PowerEngineer]

Originally posted by: EricMartello
Ah, I'm not trying to disprove anything. I'm merely stating that there is no definitive answer, and I am saying that a theory is just that - a theory. My first answer to the OP is still the same: WE DON'T KNOW! But it sure is fun to guess, right? I am sure that stuff that we don't know does matter, but going all religious zealot and "putting faith in theories" when you're working with science is not the way to make progress. Einstein set the limits for his theories, and since we have not been able to test any of those limits, it's only logical that - to date - his theories "check out".

I can go down your road a little ways, at least in the sense that there will always be areas outside the bounds of established theories that require further refinements. Adherents to superstring theory might argue that.

However, it's not very often that "revolutionary" new theories actually contradict their predecessors. The speed of light was actually set as a constant (regardless of direction) by Maxwell's equations. Relativity was Einstien's explanation of how Newtonian ideas had to be modified to accommodate it. Even so, Newton's equations continue to work very well -- as well today as they did in his time. With this in mind, I suggest that it's very unlikely that some new theory will suddenly make relativity "wrong" or remove the speed of light as a universal maximum.

Your suggestion that relativity hasn't been tested seems strange. Since its publication, scientists have been putting its predictions to the test. So far, it's passed every one. It seems to me that the very existence of nuclear weapons should make you think that Albert must have been on to something.

 

[Foxery]

Originally posted by: EricMartello
Einstein basically decided that light speed (in a vacuum) is the glue for "spacetime", and it is not possible to match or exceed light speed because of "infinite energy requirements". I dunno, for a guy who probably never moved more than 200 MPH...that's a lot of speculation.

Einstein set the limits for his theories, and since we have not been able to test any of those limits, it's only logical that - to date - his theories "check out".

That's not true. (Emphasis added) This is exactly what Particle Accelerators such as CERN do - we actually have moved small objects at speeds approaching c, and we have observed that they behave as the math predicts.

-Their mass does increase
-The energy required to push them faster does increase exponentially
-Their temporal reference frame does slow down

All of these things have been demonstrated exactly as Einstein said. You can't accuse us of "blindly following theories" when they HAVE been tested.

By the way, when I said you were welcome to prove it all wrong, I wasn't being sarcastic; science encourages new ideas, and you would become very famous if you could do this. So far, however.....