Why is there a speed limit in the first place? Is this question even answerable?
2007-04-20 12:05:54 · 9 answers · asked by the redcuber 6 in Science & Mathematics ➔ Physics
I mean: why can't light (or any other object) move faster than 299,792,458 m/s?
2007-04-20 12:41:33 · update #1
Stop banging your head trying to figure out some deep why. It's just an observed, empirical fact that nothing travels faster than the speed of light. That fact has some interesting consequences (special relativity theory). But the constancy of speed of light is a POSTULATE of not a consequence of relativity theory. The only proof we have is that we've looked and we've looked and we are still looking, and the speed of light is always constant. That nothing can go faster is a consequence of that fact.
2007-04-20 13:12:21 · answer #1 · answered by Anonymous · 1⤊ 2⤋
The OBSERVED speed limit is the result of time travel, but from the perspective of the person or thing travelling, there is no speed limit.
If you draw two lines in the sand on the beach, run from one to the other timing yourself, and then divide the distance by the time to get your velocity, there is no limit to how fast you can go. However, as you run faster you will begin to travel through time at a rate that is 1/sqrt(1-v^2/c^2) faster than normal. So say that you run some distance in 2 seconds, but you are moving into the future 150% faster than normal. At the end of your journey you will have travelled one second into the future, compared to the people watching you. They will time you as finishing the distance in 3 seconds, and so from their perspective you are moving slower. If you play around with the math you will see that your observed speed is always slower than c.
Beginners who ask this question are always told something like "The mass of the object increases as you increase velocity in a way that you can never push it faster than c." While its true that an objects resistance to acceleration changes with velocity, this is a result of the time travel effect mentioned above (acceleration is distance/TIME^2) and not the cause of it.
2007-04-20 21:46:52 · answer #2 · answered by b_physics_guy 3 · 0⤊ 0⤋
Firstly, you need to fix your question. The way you have it worded is like saying, how come A car can't travel faster than a car? You're asking how come something can't out do itself.
However, I'll try and answer what I think you're trying to ask.
Light is the ultimate speed because as any massful object apporaches the speed of light time is tremendesly slowed for the object, and it's mass becomes enourmas. To large for the Universe to contain. Luckily, Light, which is made up of photons, are massless. This permits them to travel at such high speeds. Also, if something object, somehow, was to surpass c, (which is the Speed of Light) then it would go back in time. Also, at c, time is halted. However, something can go faster then the speed of light, if you'll consider it that. That being gravity. Namely, a black hole. It can curve, and rip space so much, that it can drag any force into it. Including light. Light, although massless, will bend into a black hole, which is permitted by Einsteins General Reletivity.
2007-04-20 22:47:31 · answer #3 · answered by Anonymous · 0⤊ 1⤋
Nothing in this dimension can travel faster than light. An object that has mass will increase in mass as it approaches the speed of light ,and at the speed of light it would have the mass of infinity . The only thing that can do that is the collapsing gravity of a large star.
2007-04-20 20:35:26 · answer #4 · answered by JOHNNIE B 7 · 0⤊ 0⤋
Actually, it can, but that's a bit more advanced than I fathom you're asking...
The speed of light is defined by the speed that light travels.
It's not that there is really a limit, it's just the fastest speed we have, as of yet, been able to produce. Oddly, this speed is very common, so it is used often.
2007-04-20 19:16:02 · answer #5 · answered by slathered_in_sauce_sarcastic 2 · 0⤊ 0⤋
According to Quantum Electrodynamics (QED): Photons do have a small probability amplitude to travel at speeds lower and higher than c. However, when a photon travels at everyday distances the probability amplitudes to travel subluminal and superluminal speeds actually cancel out leaving the speed c as the most likely probability path for the photon to travel at.
It just so happens that c is the speed when the probability amplitudes do not cancel but reinforce.
2007-04-20 20:45:58 · answer #6 · answered by Phillip 3 · 0⤊ 0⤋
Because, no matter how fast light traveled, it would travel at the speed of light.
2007-04-20 19:10:46 · answer #7 · answered by Jerry P 6 · 0⤊ 0⤋
Light cannot travel faster than itself. Maybe if you reword the question and clarify?
2007-04-20 19:23:34 · answer #8 · answered by bb jo 5 · 0⤊ 0⤋
er good question?
2007-04-20 19:17:54 · answer #9 · answered by Anonymous · 0⤊ 0⤋