Dilation Definition and 1000 Threads

If we use one gravitational field in GR and try to desribe it, we will see that from the perspective of the observer on the centre of mass of the object the clock on the hovering observer (farther away from the gravitational field) runs faster, while from the hovering observer's perspective the...

two spacecraft s travel parallel to each other along straight lines AB and CD as shown in the picture here ... while s1 moves with a simple harmonic motion , s2 moves with a constant speed and only at points A and B it gets enough thrust within a very negligible time to reverse its direction of...

i have been wondering about this for a while ... suppose , a spacecraft in space moves with a simple harmonic motion ( e.g. on a straight line ) between points on space A and B . it fires a rocket from point B that travels with a speed .9c ... now if the rocket comes back to point B after a...

My question is about comparing the time dilation of a clock on a spinning disk versus a clock in the vicinity of a massive object. It seems there should be a connection between the two, because of the equivalence principle, but I'm missing something because I don't quite get the answer I would...

Since relative velocity time dilation is due to an increase in velocity, with a person moving faster moves through time slower than those on earth, does it follow that it's possible to move slower than the Earth and therefore move through time faster than them? Because the Earth is moving...

I was having a discussion with a colleague earlier today regarding exoplanet exploration. Being that the biggest challenge for mankind to travel to distant planets is that time dilation would make such an extreme effect that by the time we reached our destination thousands of years may have...

As I understand time dilation, at 90% of the speed of light, a space traveling twin would age at a rate 44% of his/her twin on earth; at 99% it would be 14% and at 99.9% it's 4.5%. And these differences would be permanent. Since relativity explains things in terms of spacetime, does this mean...

When the observer B is traveling at a very high speed, the observer A on the ground will record a time dilation. But at the same time,from the point of view of B, A is also traveling at a very high speed relative to B. Here comes the question:does that mean they both record the time...

Homework Statement A plane is moving at a constant speed of 300m/s. If you are inside and you shine a light towards the back of the plane, how will light appear to move from the Earth's frame of reference? Homework Equations None The Attempt at a Solution Light always moves at 3x10^8 m/s so...

I looked through this thread here regarding how fast we're moving relative to the CMBR, but I wonder if it would be hypothetically possible to get an even better measurement while also looking for a decent value for 'absolute still' using the apparent asymmetry of time dilation/constriction. A...

Here (at ~3:50) they say if the ship reaches 99% of the speed of light, a single day on the ship = year on Earth. But it looks like it's going to be one week on Earth. http://cosmology.com/images/3TimeDilationTable1.jpg Is it just a simplification of some sort in the video?

EDIT: split from "twin paradox with a twist" thread Re: https://www.physicsforums.com/threads/twin-paradox-with-a-twist.791673/page-5#post-4985729 one question: on the charts I understand the reflections as being at the speed of light correct? what would change in the case of FTL...

I understand the theory of special relativity and the mathematics which support it. I even understand that the time dilation has been proven. Therefore I am going to ask a question which on first blush may appear that I disagree with it but that is not the case. The question I can not seem to...

I want to ask a question about science/physics. To me and my level of education, this has not been answered, though I am sure there is someone out there that can provide the answer. It regards something I have been pondering due to gravitational time dilation (and space dilation I suppose, if...

I was reading in Clifford M.Will's book "Was Einstein right? Putting General Relativity to the Test" that there was an experiment done where in October 1971 an experiment was done with radioactive clocks, and plane trips taken going with the spin of the earth, and against it. He reports: "The...

Please forgive my ignorance in STO, but I don't understand something about the following thought experiment. Spaceship flies from Earth with large speed. We observe the clock inside the spaceship from Earth with strong telescope. We see the clock showing 12:00. When we see on the clock 12:05 (in...

I'm fairly new to the concepts provided by special and general relativity, and was wondering if someone could provide an answer to a thought exercise I came across regarding time dilation on an object going near light speed. Say a spaceship were connected by a live video feed to a monitor on...

I've been trying to get my head around time dilation in order to understand the relationship between space and time. I do not have a maths brain, I tend to understand things better as narrative concepts. I've read a lot of introductory material, but I'm having trouble making the link between...

I don't understand the thought experiment where a photon hitting a reflecting surface and traveling back to the observer is viewed from two frames of reference and the concept of time dilation is suggested arguing that the distances traveled by the photon are not the same in both the frames even...

On a science test that I took the other day, one of the questions inspired me to ask a question of my own. The original question was a multiple choice question that went something like this: if someone shoots a gun horizontally and simultaneously drops another bullet, which one would hit the...

Why isn't length contraction permanent even though time dilation is? It's my understanding that when something is going near the speed of light in reference to an observer, time dilation occurs and time goes slower for that fast-moving object. However, when that object goes back to "rest", it...

Homework Statement Two spaceships are traveling with a relative velocity of 1.2x10^8 m/s, both carrying clocks. According to the captain of each ship, the other captains clock ticks more slowly than his own. By what factor do the clocks disagree? Homework Equations 1/(1-(v^2/c^2))^1/2The...

Let's say the gravity around a planet of mass M is accurately modeled by the Schwarzschild metric. Then an observer (A) at infinity sees a stationary clock (B) at distance R from the center of the planet being gravitationally time dilated by the factor ##\sqrt{1-\frac{2GM}{Rc^2}}##, i.e. if B...

I was recently exploring time dilation from Gravity and from velocity and I came up with an interesting derivation that I have not seen before. I was wondering if there is a paper published showing these relationships like this before and where I could find it? First you start with the...

Why must time slow down when a body moves with respect to a reference frame at rest ? Why should its mass and length increase and decrease respectively when a body travels faster and faster ?

Hi, In the often cited example of a person in a rocket traveling past Earth at high speed - I think I understand that both the person on Earth and on the rocket could view the other as being the party that's actually moving. And so if they could view the other party, they would both see the...

I understand that this topic have been discussed many times, but I just haven't found the answer, at least one I could understand. I'm not a physicist, just curious. I've been reading all around the internet about time dilation and SR. I understand that time dilation is real, at least when it...

Hello , my question is : If we could observe a planet life so far away from the Earth with so much gravity that it makes time pass more slowly on that planet , what would we see? Like what can we say about motions of lifeforms living on that planet? Would they be moving in slow-motion in the...

Just wondering if you are observing someone from a far out distance and they are in a gravitational field going at a high speed would the time dilation from their speed add on to the gravitational time dilation?

Hi all, I was wondering if anybody else here thinks the concept of space-time dilation/concentration (curvature) is a little bit funny, not in the sense of it having an effect on the neighbouring particles, but in the sense of actually stretching or contracting, as though it itself had certain...

It pains me to even type these out. I realize how many threads there are with very similar questions and to someone well versed in these topics, these questions probably all seem the same. But after reading what seems like all the questions, I feel I'm still confused. 1) In regards to the light...

Who first came up with the light clock on a train thought experiment.

Why does time dilation occur due to the velocity of a moving body, according to SR?

Inspired by the movie Interstellar which featured a planet orbiting a rotating supermassive black hole with an extremely high time dilation factor (slowed by a factor of 60,000 relative to observers far from the black hole), I was wondering if anyone knows of an equation for time dilation of...

So I have seen time dilation written as all three of the following: t=τγ, Δt=Δτγ, dt=dτγ. I'm assuming this not to be the case, but just wanted to clarify that the third (differential) notation does not imply that t=∫τγ? That really wouldn't make sense (to me at least), so I'm assuming that...

I am doing a presentation and want to make sure I'm not misunderstanding something very fundamental. My argument goes like this: t0 = ϒt Santa is moving very fast and from his point of view he is in proper time. This means that if it takes him t0 seconds to deliver a present, the amount of...

A question about time dilation.. I find myself in an argument / discussion about the theory of time dilation, and it seems to me, that the terminology is really the problem. Would it not be more accurate to say that the effects of time slow, as speed increases ? To say that our test of clocks...

I have what might be a silly question about time dilation caused by gravity. My understanding (very basic) of it thus far is as follows: 1. A clock (time) will tick slower when close to a gravitational source that a clock that's positioned farther away. 2. This affect has been measured in the...

I browsed a lot this forum to find an answer, but it always ends up in the same way : no constant answer. I understand how time dilation relative to speed or to gravity separately work. But what about an object orbiting at high speed (natural ans stable orbit) an other object with a...

If I am an astrounaut in orbit, i would "see" events down at Earth happening at a slower rate. For example; if i watch a dragrace between two cars down at the surface from the orbit, i would see the cars driving slower then what i would see if i were standing at the racetrack. Offcourse, when i...

Observers that pass each other with a relative speed close to the speed of light will observe length contraction and time dilation at the other observer. In a spacetime diagram, this would be represented by two worldlines making an angle, right? Some textbooks suggest that some of the length...

Hello, I hope somebody can help me with this question. Homework Statement I have to prove that time dilation is a reciprocal effect by only using the Postulates of Minimal Relativity Theory: 1. Let I be an inertial frame, then I' moving with a constant velocity in a rectilinear motion with...

I know there have been a lot of other threads on this topic but I wanted to get some feedback on my thoughts on this. Time dilation is a result of Einstein's second postulate of SR, although the first postulate is what gives rise to the apparent twin "paradox". The common solution to the paradox...

How does one get time dilation, length contraction, and E=mc^2 from the spacetime metric? Suppose all that you are given is x12 + x22 + x32 - c2t2 = s2 How do you derive time dilation, length contraction, and E=mc^2 from this? What is the most direct way to do this?

If an object falls through a planet's entire grav. field, before impact it's velocity will be the escape velocity. I assume the time dilation for an observer on the object will be the same as for an observer on the planet. They're not added together. Another point - since time dilation on a...

Homework Statement In terms of the energy involved (using formulas provided), explain why accelerating a spacecraft to the speed of light is impossible. Homework Equations time, mass and length dilation formulas, and a few astrophysics formulas, E = Ek + mc2, projectile motion formulas The...

Consider two events that take place at the origin of the frame of an inertial observer O' . At times t_1 ' = 0 and t_2 ' = T . O' moves with a constant speed v w.r.t. another inertial observer O . 1. Use the Lorentz-transformations to show that these events occur at x=vt in the frame...

Homework Statement Hi, I have an exercise where we are supposed to find a condition for which two clocks are synchronise if one clock is accelerated. Homework Equations The time dilation in an inertial frame moving with velocity v is well known. t'=\frac{t}{1-\frac{v^2}{c^2}} The Attempt at a...

I really need an expert for these two: 1. How can we correct the clock of a satellite due to time dilation effect due to its motion relative to the ground when ground-based clocks can be equally considered in need of correction due to their motion relative to the satellite? Both equally valid...

Hello, thanks for reading this. I need help trying to find a way to calculate the time dilation due to gravity, from a satellite 50,000km above the surface of the Earth, traveling 10,000km/h relative to a stationary observer on Earth. A signal is being sent from the satellite to the observer...