Time dilation Definition and 999 Threads

Is time dilation a factor in the calculation of the expansion speed of the universe?

Hello PF, A question on special relativity I've not found an answer to,I tried to google it but no luck, so here is it : If you were to observe a moving body whose speed is very near to the speed of light, will you see it slowly due to time dilation, or you'll observe it as it really is, very...

Dear PF Forum, I have a tought experiment here. I'm asking about twins paradox, but instead of using twins, I'm using clocks to lock them up in a closed room. Sort of Einstein elevator. (unlike Schrödinger, even in tought experiment, I can't imagine locking human being -- or cat -- in a closed...

Let me begin with the fact I am a rube in the field of Quantum Physics. I seem to have an innate grasp of certain concepts but if it comes to proving theory with math, I’m out. That being said, I am completely fascinating with Miguel Alcubierre’s theory on collapsing, or “warping”, space...

[FONT=Verdana]I'm currently reading https://www.amazon.com/dp/0199236224/?tag=pfamazon01-20. The book claims that, according to the equivalence principle, acceleration and gravity have the same effects. So if gravity slows down time, shouldn't acceleration also slow down time? The book seems to...

In case when we have accelerating spaceship without any influence of gravity, what is causing the time dilation? Is it primary caused by the speed of the spaceship or it is caused by acceleration leading to higher speed? What is the primary cause of time dilation?

Would the universe end if you entered a black hole? What I mean by this is that due to time dilation would time elapse so fast for the universe outside the black hole relative to you inside it that all the stars would burn out and all that wouild be left would be other black holes?

Does time go slower on the hemisphere of Earth that is currently rotating counter to Earth's orbit than the side the side that is rotating with Earth's orbit

Hi. If calculations of the Lorentz factor are by thought experiments using the constancy of the speed of light in inertial frames (I also know of using simultaneous equations for a light signal in two different frames with a conjectured Lorentz factor to calculate it but this also involves...

According To Einstein's Relativity. Supposing a Man Went To Another Planet That Has a Gravity More Than Earth Hundreds Of Time Which Means That Time Is Too Slower There Than Earth. If We Say That 1 Hour In That Planet Is 10 Years On Earth And He Stayed 2 Hours There Will He Comeback To Earth...

Homework Statement A muon has a lifetime of 2.20 x 106 s when at rest, after which time it decays into other particles. A) Ignore any effects of relativity discussed in this section. If the muon was moving at 0.99 c, how far would it travel before decaying into other particles, according to...

Hello. If time is infinitely dilated at the edge of the EH, how do we observe accretion?

Im looking for some easy equotation which would help me to make graph of time dilation depending on gravity expressed not in relation to Schwarzschild radius but simply and directly to gravitational acceleration. I would like to get some easy graph similar to this...

This is something I've been meaning to write for a while, I finally got the time to do it, though the topic isn't currently "hot". I'm sure it will pop up again, though. Imagine we have two observers, moving at a constant velocity relative to each other far away from any objects that might...

How close do you have to be from a black hole to experience noticeable time dilation. I always believed you will not experience noticeable dilation until you are at or in the event horizon is this correct? Also does rotation/spin of mass such as a planet decrease it's inherent gravitational...

Hi everybody, I'm learning Special Relativity, and probably ok with four vectors, the metric equation, the Lorentz Transform, and the Doppler shift, etc., but enough about me. I'm still a little confused about time dilation. In several hypothetical examples of SR that I have seen, two...

When a spaceship accelerates to 1.000 kmh, the effect of time dilation is tiny. But what happens if this spaceship accelerates in an inertial frame whose total speed is much slower or whose time goes much faster, will the time dilation effect be the same? If the spaceship travels in a inertial...

I have been asked about time dilation which I thought I understood, but maybe you can help me provide an answer? If a spaceship is traveling at 0.866c then time will slow by a factor of 2 due to the speed the spaceship has. Why? If it is alone in space, light years away from any other body...

I'm under the impression that one sees clocks slow down when watching distant objects approaching strong sources of gravity, such black holes. And that objects in an elliptical orbit travel faster when they are near their attractor. I can't quite figure out how these two phenomenon work...

Wondering if it's possible that black holes create dark matter and dark energy from the matter and energy they consume. Then, inflation might slow when supply is low. This would support author Tarō Gomi's theory that "everyone poops." What role would time dilation play if that's what's...

Assume you have a 2 particles sitting inside a double potential well. Each particle occupies one side of the well and given enough time the particles may both be found on the same side or swap sides (tunnelling). Assume that the well is inside a gravitational field. It is positioned in such a...

Hi all,as I understand it, GPS satellites are offset prior to launch in order to correct for the time dilation that they experience in orbit. I am very confused about how this works in practice. I think the velocity of a GPS satellite wrt a position on Earth would depend on the position on Earth...

If an observer was traveling with a Lorentz factor that would make that observers time slower than someone's on Earth, what would that observer see watching a live video feed, or if it was possible to observe Earth with a telescope, and vice versa? I understand that either party would only see...

I had asked this about 2 years ago - but for the life of me cannot find it. Please feel free to cancel this if you can find my OP. Anyhow my question was this: A "train" passes by at significant relativistic speed, along the "x" axis. "Platform" observer peers in windows of train as it passes...

IIUC, there are two different interpretations of GR - either as curvature of space time (as in Misner Thorne Wheeler) or as a (spin-2)field that influences all matter (as in the books by Weinberg or in the Feynman Lectures on Gravitation) and that leads to the underlying Minkowski metric being...

Hello! I have some confusions about this topic, I'm a physics newbie so my question may have no sense, please have mercy ;). It's supossed that relativity only considers observation as valid "what we see", but observation it's independant of what we know (we can't tell how distant we are from...

Homework Statement The new earth-Pluto SuperShuttle line boast that it can take you between the two planets (which are about 5.0 h apart in distance) in 2.5 h according to your watch on board the shuttle. Assume that the shuttle travels at a constant velocity. a.) What time interval must the...

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...

Would an accelerating expansion create any time dilation effects? And once the expansion velocity between any two adjacent points reached c would time stop altogether?

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...

As you approach c time slows. Relative to an observer. But it is an actual thing. A material thing can be seen to have not aged as the observer did, right? Well if time slows then an atom cannot vibrate at the same frequency as 'normal'. It must be slowed. An atom vibrating at an...

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 made this pic to illustrate my problem. A spaceship (labeled B) departs from a space station (labeled A) at 80% the speed of light (0.8c). A applies the time dilation principle and calculates that B's clocks are running slower than his. Some time later a smaller craft (labeled C) detaches...

Homework Statement Let S and S' be two inertial frames of reference where S' is moving at a velocity of 0.6c relative to S. When x = x' = 0, t = t' = 0, where t and t' are time of the clocks on S and S' respectively and x and x' are the x-coordinates of the S and S' frames respectively. An...

Homework Statement Use the Lorentz Transformation equations to derive the formula relating the time period of a moving clock to that of a stationary clock Homework Equations X'=y(X-vt) Y'=Y Z'=Z t'=y(t-vx/c^2) The Attempt at a Solution t'=1/sqrt(1-(v/c)^2) . (t-vx/c^2)

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...