The speed of light is fundamental universal constant that marks the maximum speed at which information can propagate. Its value is $299792458\frac{\mathrm{m}}{\mathrm{s}}$.

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Why doesn't pushing balls in a tube propagate the movement faster than the SoL? [duplicate]

Possible Duplicate: Is it possible for information to be transmitted faster than light by using a rigid pole? On one episode of QI they asked the question, "How fast do electrons move ...
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Is there a way to formulate relativistic dynamics in a way that “hides” the finite speed of light?

I'm not referring to the dimensional choice that makes $c=1$; rather I'm imagining something more about replacing all references that apparently involve velocities with the appropriate $\gamma$ ...
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Questions about the speed of light and the extent of the universe

What is the reason that speed of light is the maximum speed in the universe? Why there is no speed swifter than light? Or is it just we haven't found yet? A similar question is like this: why the ...
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Photons arriving from the Sun

Given that the Sun is a bit less than 10 light minutes away from Earth, is it correct to assume in principle (I understand actual processes in the core of the Sun make the situation at a photon's ...
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The Effects of Moving Matter Across Light-Year distances

If I were to stand at one end of a light-year long metal pole, and another person were to stand one light-year away at the other end, and then I were to push on my end of the pole. How long would it ...
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Speed of light in a vacuum

I see many references to the speed of light in a vacuum implying that it is only truly a constant measurement in a vacuum. I can live with that, but what kind of vacuum? Are we still talking about ...
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Is a preferred reference frame of the universe the old aether?

About two years ago I posted a question about a symmetrical twin paradox: Here. Recently a new answer was posted and an intense discussion ensued: Here. One of the points discussed concerns a ...
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Could we have assumed the speed of light to be different in different reference frames?

Ptolemy's model of universe assumes that our earth is the static center of universe and everything else move relative to it (ref: The grand design ch:3). This model would give us a consistent picture ...
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Refractive index inside a fibre

The refractive index $n$ of a fibre is calculated as; $$ n = c_0/c_m $$ Where $c_0\approx 300000km/s$ is the speed of light in a vacuum, and $c_m$ is the speed of light in the fibre in question. How ...
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Could some Red and Blue shifts be the result of light passing through “dark matter”? [closed]

As i see it, light behaves in certain ways, as the Double Slit experiement shows, So when light comes into contact with dark matter, it becomes both a wave and a particle, the wave is bent around the ...
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Is 2.5x speed of light possible between two objects?

These news are in Finnish: http://www.hs.fi/ulkomaat/Kaukaisin+havaittu+galaksi+et%C3%A4%C3%A4ntyy+maasta+valoa+nopeammin/a1305618680897 The main excerpt is: "Distant galaxy moves away from us as ...
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Difference in velocity of light in change in medium [duplicate]

It is often seen that according to physics the light changes it's velocity according to the medium through which it is traveling. So can it be explained that why so happen?
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Is there any law that prevents an object with mass to become massless?

I got into a discussion with my physics teacher about the speed of light and I asked What if an object with mass was to lose mass as it gained speed-- would that allow for an object to eventually ...
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Another faster-than-light question

Imagine we have something very heavy (i.e supermassive black hole) and some object that we can throw with 0.999999 speed of light (i.e proton). We are throwing our particle in the direction of hole. ...
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How realistic is the game “A slower speed of light”?

The game "A slower speed of light" from MIT claims to simulate effects of special relativity: Visual effects of special relativity gradually become apparent to the player, increasing the ...
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Time dilation $t'=(1-\frac{v}{c})t$ instead of $t'=\frac{1}{\gamma} t$

Suppose we have a train moving. When the origin of train's frame coincides with the origin of observers frame; the the time is set to zero. At that very instant, a photon is emitted from train towards ...
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If nothing in the universe can travel faster than light, how come light can't escape a black hole? [duplicate]

Possible Duplicate: How does gravity escape a black hole? If nothing in the universe can travel faster than light, how come light can't escape a black hole? I mean, Einstein's relativity ...
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Does $\lambda\nu = c$ hold for all the waves in the universe?

Are all waves in the universe the same as electromagnetic waves? Basically, my question arises from an equation I found in my chemistry textbook: $$\lambda \nu ~=~ c.$$ This states that the ...
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Speed of light and virtual particles

After becoming extremely bored while studying for an Afrikaans exam, I started thinking about virtual particles. So, can light (photons) interact with virtual particles (even though they only exist ...
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Faster than light due to reference position [duplicate]

Possible Duplicate: Travelling faster than the speed of light Please try to follow and clarify me I've been curious about this for a long time as it seems a bit paradox due to the rule that ...
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A light and magnetic mirror paradox?

If light is an electromagnetic wave and lightspeed is constant (we ignore spacetime or gravity for this question) why can't we slow down light with a few dozen wellplaced magnets and electricly ...
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What is the length of 1 second in meters

If time is treated as a fourth dimension of spacetime, what is relation between length and time units? Or in other words, how can I convert time units to length units, for instance seconds to meters? ...
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does force affect light's path?

Say If I'm running to north at a very high speed. And as I'm running, I'm shooting a beam of light toward west, will the light go completely west, or it will have some degree toward north too?
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Is it possible to reduce speed of light? [duplicate]

Possible Duplicate: What really cause light to appear slower in media? This came to me as a question from one of my friend while I was convinced that the answer is NO. But I have read in ...
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Faster Than Light Communication Using Gravity?

Suppose two parties $A$ and $B$, some distance apart and at rest relative to each other both had control of one massive local object each. If party $A$ lifted their local object upward relative to ...
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Reaching the speed of light, rockets [duplicate]

Possible Duplicate: Double light speed Someting almost faster than light traveling on something else almost faster than light Well I've been wondering quite a long time about this ...
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Measure absolute speed

Currently I'm 17 years old, going to secondary school. So, my ideas might be totally wrong... I know that everything is relative. In the example of speed, the earth moves, and the galaxy moves, etc. ...
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What happens with photon when it is slowed down substantially?

In a dispersive media light's velocity can change substantially. Imagine we can slow it down to near 0 what the wave would look like? Frequency of light does not seem to change even at v=0 (at least ...
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What happens when atoms speed up to extreme velocity?

The title might be misleading, but my question is in regard to what happens when we reach temperatures close to absolute zero (Kelvin). I've found different quotes as to what happens on the low end of ...
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Is a compact universe consistent with the results of (for example) the Michelson-Morley experiment?

If the universe is compact then there is a twin paradox that is resolvable only by selecting a preferred inertial reference frame (arXiv). I was under the impression that the lack of a preferred ...
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When traveling close to the speed of light

I hope this isn't a stupid question for you guys but here we go. As you travel close to the speed of light, it is to my understanding you gain mass.. does this also apply when the brain sends ...
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The vacuum light speed: Is it really constant, i.e., independent of location in space-time?

I am by no means an expert in this field, however something puzzles me about the speed of light and the relativity of time and space (space-time). Is is universally acknowledged that the speed of ...
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Would it be possible to develop special relativity without knowing about light?

My understanding of special relativity is that it is fundamentally based on the constancy of the speed of electromagnetic radiation - that this speed is a physical law (or derivable from physical laws ...
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What happens when a photon hits a mirror?

When a photon of light hits a mirror does the exact same photon of light bounce back or is it absorbed then one with the same properties emitted? If the same one is bounced back does it's velocity ...
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Has the speed of light changed over time?

Could someone judge my (stoner) hypothesis that the speed of light has changed over time -- ie. as the universe has expanded in volume light has slowed down, perhaps going so far as back to the big ...
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How would be tv reception in a spaceship travelling close to speed of light?

My little brother has made me a tough question (specially for a computer science engineer). Imagine that there is a spaceship orbiting earth close at nearly speed of light (say 99%). Someone in earth ...
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What were the intention/conclusions for Michelson-Morley experiment?

Which of the following were the intentions of M&M? to disprove the existence of aether. to show that the aether has no effect on matter and energy and therefore is as good as non-existent. ...
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If a star were to suddenly dissapear, would it still have gravity?

I am wondering whether or not literally anything can travel faster than the speed of light. For example, if gravity from a star immediately ceases to have an effect if it suddenly and magically ...
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Why do photons travel?

Photons travel at the speed of light. Is there a known explanation of this phenomenon, and if yes, what is it? Edit: To be clearer, my question is why do photons travel at all. Why do they have a ...
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Two trains at the speed of light [closed]

Okay. Two trains travelling towards each other at the speed of light. So, from one train (let's call it train A), the other is moving towards it at the speed of light. The other train shines a torch. ...
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Galileo's dictum and how light cannot violate it

Okay. So I've been told that the speed of light is constant and cannot violate Galileo's dictum, but even if it weren't constant (in a vacuum), how would it violate it anyway? Say you are on a train ...
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How is light affected by gravity?

Light is clearly affected by gravity, just think about a black hole, but light supposedly has no mass and gravity only affects objects with mass. On the other hand, if light does have mass then ...
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Is it possible to build an instrument which can travel faster than light? [duplicate]

Possible Duplicate: Accelerating particles to the speed of light I have heard about atomic rockets in novels which have the capability to travel faster than light. I have also heard about ...
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Special Relativity Second Postulate

That the speed of light is constant for all inertial frames is the second postulate of special relativity but this does not means that nothing can travel faster than light. so is it possible the ...
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Does the (relativistic) mass change? Why?

I learned recently that when an object moves with a velocity comparable to the velocity of light the (relativistic) mass changes. How does this alteration take place?
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Could the Higgs boson field be responsible for the dramatic mass increase when an object begins to travel close to the speed of light?

could the Higgs boson field be responsible for the dramatic mass increase incurred when an object nears the speed of light?
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Why are objects at rest in motion through spacetime at the speed of light?

I read that an object at rest has such a stupendous amount of energy, $E=mc^2$ because it's effectively in motion through space-time at the speed of light and it's traveling through the time dimension ...
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Does the speed of light vary in noninertial frames?

The speed of light is the same in all inertial frames. Does it change from a non-inertial frame to another? Can it be zero? If it is not constant in non-inertial frames, is it still bounded from ...
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What is the speed for an object that travel close to the speed of light?

I have some questions regarding Einsteins theory of Relativity that should be fairly easy to answer. Lets say we make an experiment where we have a rocket (with an astronaut inside) that travels very ...
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Rotating mirror - Foucault's measurement of light speed

Some time ago I came across a secondary web source on measurement of light speed in water made by Foucault around 1850. I append its redrawn scheme below (light is reflected from the rotating mirror ...