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1answer
14 views

Looking out from a collapsing star

From the perspective of the surface of a collapsing star, if you were riding it in as it formed a black hole, what would you observe looking out into the rest of the universe? As you approached the ...
3
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1answer
84 views

What am I doing wrong while proving time dilation using Minkowski space-time diagram?

Consider two events A and C. They have same value of x' and time interval between them is $\triangle \tau$. This is the proper time interval between the events. ...
2
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0answers
28 views

How can you find the $u$ using time dilation if you only know $\Delta t_o$? [on hold]

I've come across two problems dealing with time dilation now that ask how fast should an astronaut go in order to travel EG: 400 LYears in 10 Years. What I can not wrap my head around is how this is ...
1
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1answer
96 views

Why does time stop its flow? [duplicate]

According to the "list verse" time gets to a pause when someone or something travels at the speed of light. But a question still lies in my mind, if time always travels forward and does not stop at ...
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2answers
61 views

When does travelling at a fraction of the speed of light appear to the traveler as if they're going the speed of light? [closed]

If a spaceship is travelling to Proxima Centari, there is a fraction of the speed of light that would make the spaceship appear to reach Proxima Centauri in four years' time. What fraction of the ...
0
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1answer
63 views

Interpretation of time dilation

Is there any interpretiation of time dilation for photons? I mean, how does time work for them? Do photons have any distinction between their own and observer's time? Or is it something like ultimate ...
-1
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1answer
79 views

Quantum teleportation + time dilation = time travel? [closed]

Thought of this a while back and thought it was pretty funny, not sure if there's been similar ideas discussed elsewhere. I can think of at least 2 reasons this won't work: 1) As far as I know, ...
3
votes
2answers
96 views

Does time have a minimum 'speed'?

Sorry if this is an ignorant question, but I've been having some trouble grasping some concepts related to time dilation. So far, my understanding of the concept says that if I am in a certain frame ...
3
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1answer
62 views

Most efficient speed to travel at, considering the effects of time dilation; according to Special Relativity

I understand that this question has recently been asked, and yet not answered to the greatest and most understandable extent, but I was wondering whether travelling at the speed of light is really the ...
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3answers
55 views

Is mass directly or inversely proportional to time? [closed]

From a Newtonian perspective: F = ma F dx = ma dx E = m (dv/dt) dx m = (E dt) / (dv dx) Mass is directly proportional to time, if time slows down then mass goes down or decreases. From a ...
0
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1answer
68 views

Gravitational Time Dilation vs Acceleration Time Dilation

I might be a little dense to this subject, but I would like to ask a question relating to this one ( Is gravitational time dilation different from other forms of time dilation? ) but asking if this ...
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0answers
40 views

What Would One Observe of a Calendar on Earth, Given a Round Trip to Another Star and back?

I want to ask a clarifying series of questions on what I think is a relatively simple scenario. It's a long one but I've tried to word it as simply as I can manage while trying to do the question ...
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1answer
40 views

Gravitational Time Dilation Scenario

Here's my scenario: One person with a clock on planet A, one person with a clock on planet B. Planet A's mass is greater than that of planet B. From what I understand, from each person's point of ...
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0answers
35 views

Gravitational Time Dilation

In my calculus class (high school), I'm writing an exploration paper on time dilation, specifically gravitational time dilation. One of the scenarios I'm thinking of looking at is the time dilation an ...
3
votes
2answers
126 views

Why time slows only for moving object and not stationary observer? How the “stationary” & “moving” are decided? [duplicate]

Explanation for the questions in the title: According to the the (special theory of) Relativity, if an observer is stationary and sees a fast moving object then time runs faster for the observer ...
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2answers
55 views

Is there a most efficient speed to travel in space with reference to time dilation? [closed]

I was thinking hypothetically, a ship traveling to a distant star system with something like food wants to get to the system as fast as possible. The trick is, we want to travel as fast as possible in ...
0
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1answer
20 views

Time dialation as observed on earth

Probably a silli q but, I wanted to know if someone has taken a wind up clock into space and observed time dialation? If all our observations are by electronic methods, we dont know if ...
1
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3answers
209 views

Time Dilation Equals Red Shift looking in or blue shift looking out

We can see the center of our galaxy. With more density near the center of our galaxy is red shifting observed from our perspective? From the center of the galaxy looking at us would a blue shift be ...
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0answers
73 views

Confusion about reading of clock as seen from different inertial systems

Suppose a clock, located at point $x'$ in the inertial frame $S'$, registers two events $t_1'$ and $t_2'$. Let $\Delta t'=t_2'-t_1'$. The same two events will be registered by two different ...
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2answers
83 views

Special Relativity and symmetry of time dilation

I stumbled across a paradox in special relativity for which I have found no answer. In the twin paradox, the loss of symmetry in time dilation is usually explained by the reversal of movement of the ...
0
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1answer
29 views

Comparing durations for two simply described motions in Schwarzschild geometry

I have some basic qualitative questions about the setup with: one satellite $A$ orbiting freely, on a stable circular path, a spherical non-rotating object of mass $M$; and another participant $B$ ...
0
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0answers
34 views

What would you experience if the universe ceased existing whilst you were under extreme time dilation?

Hypothetical situation, if you were in the center of a supermassive black hole (and managed to not be immediately obliterated), time dilation would be so that billions of years may pass outside the ...
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0answers
17 views

Basic Special Relativity Problem [closed]

A cylindrical rocket 10 m long and 2 m in diameter moves at a speed $ V=0.9c $ with respect to earth, where $c$ is the speed of light in vacuum. I. Knowing that the pilot's heart beats 70 times per ...
1
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1answer
93 views

Can you shine a laser on an object that has fallen into a black hole? [duplicate]

I've been having a small back and forth on another website about the nature of objects that fall into black holes. I know that they never reach the event horizon from the perspective of a distant ...
1
vote
1answer
74 views

How is time dilation invariant of observer?

From one observer's perspective, on all moving objects time will run slower. But from the perspective of one of those objects, it's the observer who's slow. And the answer seems to be that both are ...
0
votes
1answer
46 views

Hafele Keating in space: twin paradox redux

So Hafele-Keating made sense of the results by taking the center of the Earth as the reference frame. The westward flight "undid" part of the Earth's rotation and those clocks sped up relative to our ...
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0answers
39 views

What would be seen when a ship is accelerated to relativistic speeds and back down? [duplicate]

Consider this scenario: Two identical space ships, the SS Observer and the SS Accelerator. Each ship is indestructible and contains an indestructible clock. They begin positioned 1 light-day away ...
0
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1answer
44 views

Galileo 5 and 6 satellites testing gravitational time dilation

In today's Guardian there an article titled "Satellite launch accident provides unexpected test of Einstein’s theory" - ...
0
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3answers
100 views

Time dilation in the movie Interstellar

I know that the science in movies is questionable and sometimes ridiculous but I would think this question would have been more obvious to the script writers. When they visited Miller's planet they ...
0
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1answer
58 views

Can blue light encounter slower clock time over red?

I am aware that matter with mass experiences dilation and photon is massless. there is no inertial frame where photon is at rest. However, wave form of light has momentum and energy. Blue light wave ...
0
votes
1answer
34 views

Calculate the relativity of time of an event occurred in different frames

Imagine we have a train which is moving with a velocity and there's an observer inside of that train and there is an observer that is outside of the train observing the train moving. There's a ball ...
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0answers
32 views

Reference frame question

Two examples of possible time dilation based on reference frames and acceleration: An alien ship flies into our galaxy. They watch the arms spinning (assume they are immortal and have a LOT of time ...
1
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1answer
33 views

Time dilation (special and general relativity) [duplicate]

In special relativity we get a time dilation for high velocities near by c and in general relativity we get also a time dilation near by strong gravity fields. But what about a combination of these ...
1
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1answer
47 views

Gravity vs. Velocity time-dilation [duplicate]

Is there any difference in effects from time dilation of that due to gravity vs. that due to velocity?
0
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1answer
81 views

Time dilation: linear or exponential or other?

As you near the speed of light, time slows for you relative to the world around you. So you would be traveling at more than one hour per hour. Is the rate of time slowing for you linear or exponential ...
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votes
1answer
83 views

proper time interval

We have two frames s and s' , s' moves with a constant velocity 'v' with respect to s in positive x direction, a particle B is thrown downwards from s' , and it collides with a particle A , the point ...
0
votes
1answer
38 views

Gravitational Time Dilation and Schwarzschild Coordinates

So I'm trying to use this equation for the time dilation of an object, but I don't know how to get the distance that I have (in meters) to a radial coordinate in terms of schwarzschild coordinates. ...
4
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2answers
410 views

Does a clock oscillating in a friction-free hole through the center of a planet run slower than a stationary clock on the surface?

Assume a clock is dropped into a friction-free hole through the center of a symmetric, non-rotating planet, far from any other massive object. Clearly, the clock oscillates from one end of the hole to ...
1
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1answer
23 views

Time dilation in a space craft and at high altitudes [duplicate]

Question: In which part of a accelerating spacecraft does time pass more slowly? Therefore does time pass more quickly or slowly at high altitudes in a gravitational field.
2
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3answers
372 views

Relative Time from a far place

I have read that whenever we see the sun we are seeing the sun as it was before 8 minutes ago. Meaning if the sun were to somehow go dark we would not know until 8 minutes after. Now I became ...
3
votes
1answer
53 views

Relativistic effects of an orbit around sun in a different direction than Earth

If I manage to orbit around the sun at the same speed but in a different direction than the earth, will I perceive the time on earth going faster or slower than my own time? And what about people on ...
0
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1answer
158 views

Relativistic time dilation on Mars compared to Earth?

What is the time dilation in Mars, compared to earth? Can we accurately calculate it? What information is needed to do these calculations?
0
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1answer
42 views

Gravity and velocity increase and time effects problem

First I must specify I am a math major and not currently taking any classes on physics and this is a casual interest/hobby of mine. Therefore I apologize in advance if my questions seem naive. An ...
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3answers
175 views

Why cannot a perfect clock exist?

I have a question about the reason Feynman gives for why a perfect clock - a clock that remains in sync while in motion with a stationary clock, cannot exist. It is clear why the "light clock" ...
0
votes
1answer
118 views

Time dilation triplet paradox

Here is the twin paradox with a twist. Scenario 1: An observer (A) leaves from the equator of the earth and travels with an acceleration of $9.8\,\mathrm{m/s^2}$ in a north direction ( i.e. in the ...
0
votes
1answer
118 views

Question/Doubt about Time Dilation Symmetry in Special Relativity

Apologies if this has been asked and answered before, as I am still having doubts reconciling the symmetrical effects of time dilation (i.e each frame sees clocks of other frame slowing down), and I ...
0
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0answers
26 views

Introductory time dilation confusion [duplicate]

I'm a little bit confused about the nature of symmetrical reference frames and how they relate to time dilation. To clarify my question, I've written a scenario. Bob stands on a platform as a train ...
4
votes
2answers
65 views

The twin paradox and positively curved space

I'm reading about the twin paradox in special relativity - if there are two identical twins, one of whom who sets off in a high speed rocket to a planet, and then heads back, will find the twin who ...
2
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3answers
251 views

Muon demonstration of time dilation

Looking at the second paragraph of page 120 here. Is the half life given measured in the rest frame of the muon? Then the calculation shows that the time to reach sea level from the muon's perspective ...
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1answer
56 views

expansion of space and time vs passage of time [closed]

Is passage of time is due to expansion of space and time?And the "dilation of time(by general relativity)" due to the force of gravity held against the expansion itself,like time slows down near ...