All Questions
Tagged with spacetime speed-of-light
189
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Does light travel same distance in same time not depending of the path orientation regarding Earth's surface?
Does light travel the same distance at the same time regardless of the path orientation? The light in the proximity of a gravitational source can bend its trajectory and frame-dragging can cause the ...
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Is there a hyperplane hyperbolic orthogonal to a light-like curve?
In Special Relativity, a hyperplane that is hyperbolic orthogonal to a worldline at a point p can be viewed as the simultaneity plane with respect to the worldline at p. What if, however, the ...
- 1,073
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Is time taken by light to travel any distance 0 or finite? [duplicate]
According to relativity, Light does not experience any time. So it must travel any distance in no time.
But, we know that light has finite speed $c$. So it should take finite time.
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How can we perceive light if light doesn't move through time? [duplicate]
From my understanding in space-time everything moves at the speed of light $c$ in some direction of this four dimensional space. Light itself moves only through space, so it doesn't move at all in ...
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Is there an exact constant value for the speed of light in a vacuum distorted by a gravitational wave?
In a vacuum, construct a cylinder of photons arranged as follows:
A 'measuring apparatus' computes the speed of light as 299,792,458 m/s.
However, suppose the vacuum is distorted by a gravitational ...
- 173
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Can a frame of reference travel with the speed of light? [duplicate]
I read that nothing with mass can travel at the speed of light. Therefor one can not ask what happens when an observer in a car moves with the speed of light. But, is it possible for a frame of ...
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What is the problem with this method to measure one-way speed of light? [closed]
I am having a hard time grasping the idea that one-way speed of light is immeasurable. I have watched several videos (including the Veritasium one), read the Wikipedia article, and read some questions ...
- 510
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Using $ct$ axis instead of $t$ axis in special relativity
I've recently started studying the concept of space-time diagrams in special relativity, and I came across the concept of representing the time axis using $ct$, with units being that of length. Now I'...
- 1,791
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Is speed of light a ratio or a universal constant?
We use the speed of light to define the length of the meter, but we also use the speed of light to count the number of clicks on our clocks (because all the electromagnetic events on the smallest ...
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What is observed by Astronauts traveling from M at just under $c$, but proper distance increases at greater than $c$ due to spacetime expansion?
A rocket is traveling at a reasonable speed directly away from planet M at a large distance D. M is shaped like a coin and to the astronaut looking through a telescope directly out the back of the ...
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Why not $\frac{x}{c}$ instead of $ct$?
The moral of the parable in special relativity is that:
The same units should be used for all distances.
The (squared) distance is invariant.
Different frames are related by rotations.
Now what we ...
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How does relativity explains time-dependent behaviour for objects not experiencing time? [duplicate]
A variable electrical field produces a variable magnetic field, which in turn produces a variable electrical field, and so on, leading to an electro-magnetic wave, which is eventually what light is ...
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190
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Special relativity with horizontal mirror clock? [duplicate]
Every explanation video about special relativity comes with a constantly moving train and a vertical (according to the train's speed direction) mirror clock. So first of all, why in the classical ...
- 101
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Resulting Dot and Cross Products in Relativistic Speeds
Imagine the following problem:
Person 1 travels with velocity $v$, and person 2 has a velocity of $u$ according to the rest frame. They both travel in straight line, with an angle $\theta$ between ...
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What implications does special relativity have on the accelerating expansion of the universe? [duplicate]
Under special relativity we have the Lorentz factor:
$$
\gamma = \sqrt{\frac{1}{1-\frac{v^2}{c^2}}}
$$
Which essentially mathematically describes how the relative speeds between objects can never ...
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