# Questions tagged [time-dilation]

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### Why is the time different from the reference from of a moving stick with respect to an observer on earth?

Sorry if the title is misleading, I wasn't sure how to briefly ask the question in the title. I have a problem where a stick of length L is moving past me at speed v, there is a time interval ...
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POkay, so moving clocks run slower but there is something I don't understand when talking about relative time and proper time. Consider this example for PBS crash course relativity, it says that the ...
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### Expansion of what? [duplicate]

When people say "the expansion of the Universe" they seem to mean the expansion of the space between mass-dense regions. However, my understanding is that space and time are intrinsically linked, so ① ...
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### Special Relativity - What is an intuitive way to think about time dilation? [duplicate]

As objects move faster, their time slows down. I understand this, but what I'm having trouble with is intuitively grasping the concept of "time slowing down". A book I'm reading gave the following ...
65 views

### In the movie Interstellar, if Cooper and Brand were to transmit video footage from Miller's Planet to the Endeavour, what would Romilly see?

This question is with regard to Miller's planet, where 1 hour is equivalent to 7 earth hours. Dr. Brand and Cooper are present on the surface of the planet, whereas Romilly is on the Endeavour. From ...
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### Determining the rest frame

Sorry if this has been asked before in some way, I did try looking through the special relativity tag and didn't really see a good answer to my question. I am having trouble determining which frame ...
79 views

### Gravity Time Dilation interior to a planet

Regarding Gravity Time Dilation: We know that, in a stronger gravitational field, time passes more slowly. As one descends below the Earth's surface, how does the intensity of gravitational pull ...
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### Special Relativity - Does this thought experiment correctly prove time dilation and length contraction?

Assume you're in outer-space and a spaceship flies past you at a very high speed. In the ship, the pilot is shooting a light beam from the ground to the ceiling, and a mirror on the ceiling reflects ...
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### Special Relativity - Why does time dilation cause length contraction? [duplicate]

As an object moves faster, its time runs slower by factor X. I get why this is the case, but I'm not sure why distance is decreased by factor X as well. Questions: 1) Why does a moving object's ...
164 views

### Confusion about Time Dilation Equations

The equation for time dilation is typically given as $t'=\frac {t} {\sqrt {1-\frac {u^2} {c^2}}}$ - however, in the Feynman lecture notes, it is said that if a man moving at velocity $u$ records 1 ...
204 views

### Can a human body actually experience large gravitational time dilation?

As sometimes depicted in science fiction, can a human actually experience a large gravitational time dilation? These depictions often show a human experiencing a large dilation (ex. 1 minute = 10 ...
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### How Lorentz transformation is connected to reality and physics?

I don't understand whats the meaning of Lorentz transformation in Special relativity. In physics, the Lorentz transformations (or transformation) are coordinate transformations between two ...
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### Special relativity clarifiyng time dilation experiment

There is a well known 2 mirror clock time dilation thought experiment in STR. However it is a bit unclear to me due to its unrealistic nature. By unrealistic I mean that experiment implies that ...
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### Does STR imply that time dilation is effected by an orientation of clocks?

Many texts about STR time dilation use as an example thought experiment with 2 mirror photon clock. The conclusion of this experiment is: In a frame moving relative to the clock, they will appear to ...
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### Twin's clock slowing down [duplicate]

This question is not same as explaining Twin paradox. This question does expect that the travelling twin will age less. The question in here is what causes the travelling clock to slow down, which is ...
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### How can time dilation be symmetric?

Suppose we have two twins travelling away from each other, each twin moving at some speed $v$: Twin $A$ observes twin $B$’s time to be dilated so his clock runs faster than twin $B$’s clock. But twin ...
299 views

I've done a bit of reading about the twin paradox, as well as watched a few videos and the Wikipedia page on it, however, I don’t understand how their explanations explain away the problem. They claim ...
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### Special relativity time dilation messing with my head [duplicate]

Say we have the earth and a person on it and an astronaut travelling away from the earth in a spaceship in a straight line and then coming back in a straight line at the same speed. The person on ...
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### Time travel (Velocity and Mass)

I learned that if I move on a high velocity, if my watch shows 12:00 and a my home clock shows 12:00 before the trip, when I come back, my watch will be like 12:05 while the clock will be 12:10. I ...
494 views

### How is quantum entanglement consistent with the relativity of time?

It is well known that relativity predicts time moves slowly near massive objects e.g.. time moves slowly for clocks on earth as compared to clocks on GPS satellites by about 40000 nanoseconds. ...
583 views

### This site proves time dilation is impossible. What's wrong with their theory? [closed]

http://www.alternativephysics.org/book/TimeDilation.htm This above site logically proves that Time Dilation is a hokum. But we all know it's real. It is well-proven in GPS satellites. I can't find ...
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### Two objects are thrown into a black hole. The first crosses the event horizon at time's end, so when does the second one cross?

An observer throws an object towards a black hole, and then an arbitrary amount of time later, throws a second object towards the black hole. Disregarding Hawking radiation and assuming the Black Hole ...
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### Was time dilated in the early universe?

If energy is responsible for most of our mass, and mass is responsible for the effects on spacetime, then in the very early universe when its mass energy density was enormous, one second in time to a ...
218 views

### Does Minkowski diagram show that time goes faster in “moving” frame of reference?

I have a question re the diagram that appears at: http://www1.phys.vt.edu/~takeuchi/relativity/notes/section12.html The diagram purports to show that the observer in each frame of reference will ...
447 views

### Time dilation due to space expansion

As we observe a remote galaxy, we see it with a redshift. The most distant galaxy discovered to date is GN-z11 visible with the redshift of $z=11.09$. For simplicity, let's assume no gravitational ...
315 views

### Time dilation cancelling out due to relative motion [duplicate]

Suppose I am travelling at a speed near to the speed of light and I have a clock with me . For a stationary observer having the same clock, he would see that my clock ticks slower than his. On the ...
63 views

### How looks a wheel browsing 299000km in 1 second from its own frame?

Imagine a wheel with a 299km perimeter turning at 1000 round per second going 299000km (the speed of the wheel is 299000km/s relative to the starting frame). How does it look in the frame of a pilot ...
258 views

### Is this spacetime diagram for the twins paradox correct?

The link at question is here: http://www.einsteins-theory-of-relativity-4engineers.com/twin-paradox-graphical-solution.html My question in specific is the loop in Jim's worldline. I know that ...