Questions tagged [time-dilation]
This tag is for questions regarding the 'time dilation' which is the lengthening of the time interval between two events for an observer in an inertial frame that is moving with respect to the rest frame of the events (in which the events occur at the same location).
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Gravitational time dilation – clock falling to event horizon
Given probe that falls into BH (simple non-moving mass M) staring from distance r=D, velocity v=0 and clock t=0, what will the clock show when entering the EH (or in general as function of the ...
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Travel to the end of the universe instantaneously [closed]
Lets say we had the ability to travel at the speed of light... and we tried to go from one end of the universe to another.. Wouldn't due to time dilation.. it would've appeared to us (in the ship ...
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Does the twin paradox hold in a universe that's empty except for the twins?
I recently obtained a used copy of Shadowitz's obscure book on Special Relativity, in which he makes the following astounding claim (which I have not seen elsewhere) concerning the twin paradox with ...
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How does time dilation affect the synchronization of clocks in different gravitational potentials?
How does time dilation affect the synchronization of clocks in different gravitational potentials, as described by the general theory of relativity?
For example if we consider two clocks, one located ...
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Thought experiment with black holes and escaping rockets [duplicate]
Something about stuff ever falling in black holes always bothers me, so I made a thaught experiment that I would like to be scrutinized.
Element 1: We have a supermassive non rotating black hole.
...
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Is there a common mechanism that gives rise to spatial and time dilation in both Einstein's STR and GTR?
In both General and Special Relativity a body experiences both time and spatial dilation. For example, as a particle approaches C it experiences dilations in time and space. For a particle ...
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Time dilation effect for astronauts travelling to Alpha Centauri Sol in a spaceship at $0.87c$ the speed of light? [duplicate]
Does this mean also that if we want to sent astronauts to Alpha Centauri solar system, 4lys away with the spaceship accelerating to $0.87c$ speed of light (i.e. Lorentz factor γ=2), then the spaceship ...
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Will a spaceship moving at $0.87c$ the speed of light, age twice less? [closed]
Strangely enough, the physics community seems to me having opposing views on this, namely many say that constant speed SR time dilation effects in the rest frame of an relativistically moving massive ...
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Temperature and time dilation
Say you had some liquid radioactive isotope with a half-life equal to X. If it was cold, the molecules would move slowly, and thus there would be virtually no time dilation involved, resulting in the ...
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Travel to the future on the earth [duplicate]
Could we in theory due to time dilation put someone in a machine that moves them in a circle at close the speed of light for like an hour and then they would somehow be transferred into the future..?
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Black hole collision with a probe
I understand that for an outside observer it will take an infinite amount of time for an infalling object to reach the black-hole event horizon.
Consider a black hole that orbits around the center of ...
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Are high-energy neutrinos subject of relativistic time dilation like muons are?
Synchrotron experiments and cosmic-rays hitting our atmosphere have proved many times that high-energy massive muons moving with speeds close to the speed of light are subject to relativistic length ...
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Not "understanding" the Twin Paradox? [closed]
Many of the explanations that I've seen of the Twin Paradox seem to rely on the role of acceleration to explain the differences between the twins. But why can't we simply resolve it just via "...
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Time dilation of distant stars changed by walking or standing still, paradox?
Disclaimer, using generalized numbers here to illustrate the question, not to be mathematically accurate.
Based on my understanding, if you were standing still vs. walking towards a distant star, say ...
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Problem of deriving time dilation in different way [closed]
I tried to derive the time deliation equation in different way,but I got a ridiculous result.
Could somebody point out the problem in my derivation?
The derivation in situation 1 (stationary source &...
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Combined SR and GR effects for time dilation in uniform gravitational field
I was reading David Morin's "Classical Mechanics" Chapter 14 and he claims that the combined effect of time dilation on a body moving at speed $v$ is $$d\tau=(1+gx)\sqrt{1-v^2}dt$$ ($c=1$). ...
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Confusion about relativity and length contraction and time dilation?
So I know the equations of time dilation and length contraction given by:
$$L' =\frac{1}{\gamma}L_0$$
$$t' = \gamma t_0$$
However, I am confused about how the speed of light stays the same in all ...
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What happens in an atomic clock when moving it up/down in a gravitational potential?
From this answer, I get that an atomic clock, in principle, works as follows:
oscillator, cycles with tunable frequency $f$
counter able to count the oscillator's cycles
oscillator creates microwave ...
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Gravitational time dilation in uniformly accelerated rocket and cosmological expansion
I was wondering if, in the relativistic rocket trip problem, we should also consider the gravitational time delay formula in the calculations for the observer in the rocket, i.e., if, beyond the ...
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Something about length contraction still feels off, is there any reason we talk about this effect in terms of length
When for example, a near lightspeed particle (or any inertial observer A) is approaching earth (or any inertial object B), we say that for the particle, the distances to earth are squished. How is ...
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Confusion about time appearing to run slower at bodies with higher gravitational forces
Reading through Hawking's Brief History of time, there is passage which says
"Another prediction of General Relativity is that time should appear to run slower near a massive body like the earth. ...
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How do photons travel through time? [closed]
I was watching a video, and in this video they used a chart to explain time dilation. Basically, when you travel through space, it slows down your speed through time, since time is a dimension, and ...
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How does conservation of energy work with time dilation?
According to special relativity time will appear to have slowed down for an observer $B$ travelling at a uniform speed when observed by an observer $A$ (say 1s for $B$ equals 2s for A). If that is ...
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Confusion about why time coordinate of Lorentz transformation and time dialation don't align? [duplicate]
If there is a stationary observer and one is moving to the right at 1/2 speed of light. And there is a light moving to the right at the speed of light. I tried to calculate the coordinates of light ...
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If $\Delta t_0 < \Delta t$ then does it mean that first light signal will reach receiver faster or earlier than second light signal?
Let we have light clock.
Light signal transmits from point A to point B (receiver).
In moving inertial frame we see first light signal. Clock shows $\Delta t_0$
In stationary inertial frame we see ...
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Confusion about time dilation
Suppose a clock that ticks every second is moving at half the speed of light away from me.
Without special relativity, I would see the ticks at every 1.5 seconds, since the light from the next tick ...
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Gravitational redshift and time dilation
I understand as light moves away from gravity/curvature, let's use earth as an example, it is redshifted. Then it is usually said imagine a light clock that ticks according to the frequency of the ...
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Time dilation reciprocity [duplicate]
With respect to time dilation, apparently Russian Cosmonaut Sergei Avdeyev, who spent 747 days (64 540 800 seconds) aboard the Space Station Mir which travels at 7600 ms-1 experienced 21 milliseconds ...
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What will going near the speed of light would look like?
Person A travels in a train with a constant velocity close to the speed of light and is in motion relative to a bystander B. As of my understanding, person B will perceive person A's clock to move in ...
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Difficulty Understanding Special Relativity Time Dilation [closed]
Joe and I have agreed to shoot a photon at each other when our clocks count 10 seconds. Suppose I am approaching Joe at relativistic speeds such that I think Joe’s clock is ticking at half my clock’s ...
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Is rotation invariant under gravitational time dilation?
Imagine a giant ferris wheel with a ten-mile radius on a planet with a strong gravitational field. As it spins, different parts of the wheel experience varying degrees of time dilation due to the ...
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is $LT$ a Lorentz invariant?
We know the relations of time dilation and length contraction
$$L=\frac{L_0}\gamma\\
T=\gamma T_0$$
If we multiply them together, we get
$$LT=L_0T_0.$$
This holds for all $L$ and $T.$
So, is $LT=L'T'$ ...
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Can black holes fully merge, according to a distant observer? [duplicate]
According to a distant observer, an object falling into a black hole doesn't disappear behind the even horizon but rather red-shift due to time dilation.
Does the same apply to merging black holes? ...
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Time dilation in Einstein's train example (lightning strike)
In Einstein's famous thought example involving a fast-moving train (say with a velocity of $c/2$), we assume that lightning strikes occur simultaneously at the front and rear end of the train as ...
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Do satellites in orbit create Relativity paradoxes? [closed]
Can someone point out the flaw in this very realistic scenario below?
I will start by stating established first principles of the applicable orbital and relativistic conditions.
Then I will describe ...
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How to properly combine kinetic and gravitational time dilation effect?
I developed a time dilation calculator that includes both kinetic (Lorentz Factor) and gravitational (Schwarzschild Metric Formula) factors to assess the time difference between Earth and satellites. ...
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Do you always experience the gravitational influence of other mass as you see them in your frame?
You see a galaxy far away. That galaxy is attracting you with a certain amount of gravity. I'm wondering if the gravity influence of the galaxy on you, as measured by you, always ends up being what ...
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Tug of war between observers in frames with different rate of time
You have a very dense hollow sphere of matter. Observer A is inside the sphere inside a rocket. Observer B is in an identical rocket outside the sphere where the ring's gravity is negligible. They are ...
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Physical meaning of $vx/c^2$ in Lorentz transformation
In Lorentz transformation, this is the formula of time dilation
$$ t' = \gamma \left( t - \frac{vx}{c^2} \right) $$
It can be derivated from the formula of length contraction and be proved ...
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John, in his spaceship traveling at relativistic speed, is crossing the Milky Way in 500 years. How many supernovae explosions would he experience?
John, in his spaceship traveling at a stable relativistic speed, is crossing the Milky Way in 500 years of his own time.
How many supernovae explosions would he experience?
From my reference frame on ...
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How can I find the distance between planet and black hole?
With the movie Interstellar how I can find time dilation of the Miller's planet? Do I need find the distance between the planet and the black hole? Then I can find the time dilation?
If not, please ...
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Topological illustration of spacetime dilation: which function should I use for isometric lines spacing?
Scientific popularization, when it comes to illustrating spacetime dilation around massive objects, often relies on the description of a two-dimensional square-grid, which can be regarded as a cross-...
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When it comes to getting closer to the Schwarzschild radius, how is discrete a limit?
From Keeton (2014) in Principles of Astrophysics: Using Gravity and Stellar Physics to Explore the Cosmos, Gravitational time dilation near a large, slowly rotating, nearly spherical body, such as the ...
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Does time always dilate? [closed]
Consider a frame $O$ and a moving with speed $v$ relative to frame $O'$.
By $(x,t)$ we denote the spacetime coordinates of a point.
For two events $A, B$ happening in $O$, consider the following ...
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Time function as a function of energy (from velocity and gravity)?
Is there any formula, preferably in terms of energy, for the time dilation an object experiences taking both relativistic velocity and mass into account? I see both formulas frequently, but haven't ...
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If velocity is relative, why does time dilate for some observers and not others? [duplicate]
I'm trying to get my head around relativity and time dilation. What I can't figure out is how time can dilate for fast-moving observers if all velocity is relative. Here's a scenario:
Alice and Bob ...
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Failures on deriving the Lorentz factor: using light clocks to calculate the dilation on space and time
I wanted to check my understanding of special relativity and set up one experiment that could lead to deriving the Lorentz factor. Usually, the deriviation for the Lorentz factor is explained using a ...
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Moving observer detects incoming photon: Is this the full derivation of the relativistic Doppler effect?
I have a very trivial question that I can't quite work out. Imagine an observer moving in Minkowski spacetime. In Cartesian coordinates $(ct,x,y,z)$, their 4-velocity is
$$u^\mu = (u^t ,u^i )$$
where $...
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Does time arising from entropy agree with GR?
There's a theory that the direction of time arises from entropy and the correlations (interactions) between bodies. However, I don't see how this would incorporate the effects of General Relativity, ...
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Time dilation with atomic clocks near accelerators or colliders
Consider an atomic clock positioned close to a high energy particle accelerator or collider.
Would the atomic clock read different values when the accelerator is operating at different "energy ...
