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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1answer
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Relativity time dilatation confusion please help [closed]

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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1answer
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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 ...
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2answers
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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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2answers
724 views

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 ...
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2answers
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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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1answer
81 views

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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3answers
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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 ...
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3answers
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 ...
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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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362 views

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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194 views

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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2answers
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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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8answers
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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 ...
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3answers
299 views

Twin paradox problems [duplicate]

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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3answers
154 views

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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1answer
67 views

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 ...
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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. ...
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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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5answers
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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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1answer
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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 ...
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3answers
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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 ...
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2answers
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 ...
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1answer
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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 ...
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1answer
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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 ...
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1answer
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 ...
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1answer
97 views

The Time Freezing Room - Theoretically possible?

Imagine a room in your basement with a very special property: The time inside this room runs 60 times faster compared to the outside world. That means when you enter the room and spend there 1 day ...
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1answer
80 views

Is the matrix Lorentz transform equivalent to statements of time dilation, length contraction and effective mass?

I am not overly versed in special relativity, so do not be afraid to correct anything here that is erroneous. $\newcommand{\b}[1]{\mathbf{#1}} \newcommand{\V}[4]{ \begin{pmatrix} #1 \\ #2 \\ #3 \\ #4 \...
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1answer
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Conceptual intuition in special relativity

I am currently studying special relativity at high school and they do a very poor job of teaching it as they just tell us to apply the formulas and give us no basic intuition. Thus I have many basic, ...
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1answer
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Time dilation for increasing industrial output and life expectancy

I'd like to know an answer to a more practical question. Let us assume that there are two factories where people produce shawls with the equal speed and use the equal amount of raw material. Factory ...
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3answers
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If an astronaut orbits earth, can both Time Dilation and Gravitational Time Dilation affect it? [duplicate]

I am very new at all of this stuff and this one thing bugs me very much... If an astronaut is orbiting earth, it should be experiencing Time a bit faster than those on earth, correct? Well then ...
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2answers
340 views

Special relativity and spinning tires

I apologize for the subsequent headache. There is a person who claims quite adamantly that Einstein is wrong, using the following reasoning: A clock on a train slows down the faster the train moves....
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1answer
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Can black holes slow down a planets time to months whilst millions of year pass elsewhere?

Writing some sci-fi and want to see how accurate I can get this. Let's say there's a planet (call it A) next to a black hole and then Earth somewhere far away. Is it in any way possible for the time ...
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1answer
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Why is measuring half life or oscillation in 2 different gravitational potential well a valid proof of time dilation?

It is often quoted that if one measure the rate of radioactive decay or oscillation in high gravitational field and low gravitational field the rate of radioactive decay or oscillation in high ...
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2answers
714 views

Calculating the motion of an object under a constant force in a relativistic context

I was playing a bit with the equations of relativity, and just wanted to know how much time it would take to accelerate a mass to a certain (relativistic) velocity. Now this problem turns out to be a ...
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1answer
138 views

How does time behave inside a massive spherical shell?

According to General relativity the clocks in our satellites in the atmosphere tick faster than those on Earth, as they are farther from the gravitational well of Earth and are free falling. ...
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1answer
58 views

Linear approximation of time dilation. In what point is it?

I have watched a video about linear approximation and there was an example, exactly here: https://www.youtube.com/watch?v=BSAA0akmPEU&feature=youtu.be&list=PL590CCC2BC5AF3BC1&t=32m50s ...
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1answer
383 views

Why is the Lorentz transformation's time transformation not just the time dilation?

In Taylor's Classical Mechanics text, he derives the Lorentz transformation from length contraction which, in turn, uses time dilation. But doesn't the use of length contraction necessitate that the ...
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2answers
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Time and Light Speed [duplicate]

I have an innocent question. What is time? Can travelling near the speed of light make a person younger relative to others who don't? Then, is there any impact on the body (atoms, molecules etc) of ...
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1answer
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On the implication of two clocks colliding with respect to time dilation

Have you ever noticed, with Special Relativity textbooks, how frequently two observers with clocks in moving vehicles are passing by each other. But what if there was an accident? Perhaps the ...
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1answer
93 views

Time dilation beyond cosmic horizon

The observable universe is limited by a cosmic horizon. Galaxies beyond the horizon move away from us faster than light, so we cannot see them. If we could see a planet close to our horizon, we would ...
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4answers
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Is there a space-like equivalent of the Twin Paradox?

In the Twin Paradox, a travelling twin returns to the inertial frame of the twin that has stayed at home, and their clocks are compared. The readings on the two clocks are different, but still ticking ...
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1answer
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Relativistic Doppler Effect Rest Time vs Time Dilation Proper Time

For time dilation, both observers see the other as experiencing a time dilation symmetrically based on relative velocity to each other. In the twin paradox, however, one must be careful of which twin ...
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2answers
221 views

Time Dilation in two reference frames

This is slightly related to the twins paradox, but doesn't include the part where the twin on the journey makes a U-Turn and comes back to earth (i.e. I'm asking about where the twin is at a constant ...
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229 views

Time dilation in quantum gravity

In General Relativity, time moves slower near massive objects where spacetime is curved stronger. In quantum gravity, the gravitational force is represented by the quantum field that refers to the ...
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2answers
107 views

Relative Observations of Relativistic Motion

A commuter is riding a train that is moving at a speed of 0.75c. When the train passes a station platform, a clerk at the station picks up a magazine and sets it down. If the commuter observes that ...
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How do gravitons make time go slower?

In the classical view of General Relativity, time moves slower near massive objects where the gravitational field (spacetime curvature) is stronger. In the quantum view however, the gravitational ...
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1answer
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Moving rod experiencing time faster/slower depending on direction of motion

A rod of rest length $L$ is moving away from a stationary observer at a constant velocity $v$. At time $t_1$, a light beam is fired from the front of the rod in the direction of the observer. At time $...