Time dilation Definition and 999 Threads

For both time dilation equations (kinematic and gravitational) I have often seen \Delta t^\prime = \frac{\Delta t}{\sqrt{1-(v/c)^2}} and \Delta t' = \frac{\Delta t}{\sqrt{1-\frac{2GM}{rc^2}}} I'll calls these equations as "Set A" ------------------------ And at other times as...

I need to give a presentation on some of the physics of space travel. One of the things i will be covering is Time Dilation and Relativity. I am not too knowledgeable about this subject. What are the main topics of time dilation and relativity that i should present? I need this info as soon as...

If as a result of the equivalence principle we can derive the gravitational red shift entirely from the perspective of an accelerating body with no reference to gravity and no reference to gravitational time dilation then one is essentially just working out the Doppler shift of a signal...

Imagine a low-mass object between two massive objects. Their configuration is such that the low-mass object does not move due to the gravity of the two massive objects. Since the gravity is canceled for the low-mass object, is the time dilation canceled as well for the low-mass object...

If a low-mass object is surrounded by massive objects homogeneously so that the low-mass object does not experience acceleration, then is there any time dilation due to the gravitation from the massive objects? Thanks, Jake

Has time dilation ever been observed to occur in biological processes (e.g. the rate at which bacteria divides)? Thanks.

I have to learn about general relativity and to understand that, I need to know gravitational time dilation. I heard that time on Earth and time in space is different by few nanoseconds. How can time be different? Why does time go slowly in certain gravitational fields? Also, how can...

They say that when you go faster in space your watch would tick slower. How can the watch tick slower when the watch has a constant ticking rate determined by the gearratio? (I do understand that the rate of time decreases as the velocity increases)

Hi there Can members please review my understanding of the problem. [b]1. The problem A star is 522 light years away from Earth. Imagine that the spacecraft was able to travel to the star at a speed pf 0.9999c a) How long does the trip take, as observed from Earth? b) How...

Hi, i asked this before but i think i found a clearer way to define my quesiton. As i asked in the title, does length contradicts as a result of time dilation? Or time dilation and length contraction are equal? When we deal with formulas generally we use the vertical clock and derive time...

Homework Statement Suppose that the speed of light in a vacuum ( c), instead of being a whooping 3x108, was a rather sluggish 40.0 mph. How would that affect everyday life? Throughout this problem we are going to assume that c = 40.0 mph and that time dilation is in full effect. Let's start...

I know this has been asked tons of times on here. But I never seem to understand the answers. So I challenge all you smart people to explain it as simple as possible. How does time slow down for a person who is traveling at a hihg speed and not for someone standing still? The person standing...

I was watching the new show "Into the Universe with Stephen Hawking", and I found myself a little annoyed by his contrast of gravitational vs velocity time dilation. It was stated that if you took a spaceship, orbiting around a super massive black hole, you'd only get a 2:1 time dilation...

So I was watching a tv show when an idea just popped into my head, If let's say a spaceship left point A on Earth at (for arguments sake) 1000MPH and was to reach point B (5000 miles away) in 5 hrs. Now due to time dilation the ship itself only took 3.5 hrs to get there due to lack of...

I watched a video today about time dilation and Lorenz contraction. It had Albert stationary and Henry on a moving track, both holding a photon clock, and it showed how time slows down for moving objects, relative to the stationary observer. I get all that stuff... sorta... I was thinking...

Very simple thought experiment about time dilation: Let's say I have two clocks that are a substantial distance (light years) apart, at rest with respect to each other. The clocks are Einstein synchronized. Also, the clocks are specially designed to withstand any force or collision. However...

1. Homework Statement [/b] Just need some help getting started on what looks like a rather simple problem! A rocket travels to a star 5 light years distant, observers on the star time the journey at 6years. I need to find the time recorded on a clock aboard the rocket and the distance to the...

Homework Statement On a Starship, which travels at 0.93c, dinner is served between 8:15pm and 8:45pm, according to the clock on the ship. How long is dinner served according to stationary observes on Earth watching the ship on a video monitor? Homework Equations I believe the...

I'm still trying to understand time dilation, the twin paradox, and the effect of acceleration. Yes, I've read the twin paradox FAQ, but it only gets me so far. Here's a hypo I came up with. I've tried to simplify it by (a) making the observers symmetrical and (b) eliminating the...

Why "at rest with respect to the center of the earth"? Both clocks are in relative velocity. Does the mass of the frame of reference has something to do with the determination of the frame at rest?

According to SR theory, relative motion leads to -length contraction -mass inflation -time dilation. In GR theory, gravity leads to time dilation. Does it also lead to -length contraction? -mass inflation?

I'm trying to calculate the time difference for something orbiting very high above the moon in comparison to the surface of the Earth.

If someone is traveling close to the speed of light, relative to your reference frame, then the time observed on their clocks slows. But what does that mean when it comes to aging? Do their cells that make up their body replicate more slowly? Is there any type of disagreement in the amount of...

Hello all, having decided that I wish to apply to Oxford to study Physics (as well as Imperial and, I am still considering Natural Sciences at Cambridge), I have been informed that extra reading and independent study would be advised, so I'm delving into the world of relativity (I'm a first year...

I posted this under general physics but i feel its better suited in this section. Ok, looking at it from the point of view of the photon due to time dilation the time at which its emitted to when it finally strikes an object is instantaneous, regardless of distance, from its own frame of...

Background: I work as an engineer with someone who is an "engineer" by trade only (not by training or formal education). Un/fortunately, before asking difficult questions, he researches information, or just hears about it online and tries to muddle his way to an understanding of it. He...

Putting all practical implications aside, I was thinking about the idea of another planet that travels around the sun faster than Earth. I know that some planets do, but let's say that some day in the future we were able to create another planet, called Earth 2, that traveled around the Sun at a...

Homework Statement Calculate the difference in time after one year between a clock at Earth's surface and a clock on a satellite orbiting at 300 km above the surface Homework Equations T = T0 / (1 - 2gR/c^2)^.5 That is, this...

OK, I just made a few very basic calculations to find out the gravitational acceleration of black holes - BASED on our humble observations so far about black holes. You know mathematics(and physics) is many times counterintuitive(that said: you are surprised when you see the result...) - but...

I have a simple question. If we put a clock in a satellite in orbit for some amount of time, and then brought it back to earth, will the clock's reading of time passed be less than a clock on Earth's measured passed time. *(This is strictly ignoring any general relativistic time dilation!) In...

If someone were traveling at let's say 99.9999% the speed of light time would go slower for them but their speed would stay the same. So let's say for every ten second we would experience here on Earth they would experience they experience 1 second. so they would travel (10 seconds X...

1.) problem statement Relativistic protons that have a certain speed "v" are selected by measuring the time it takes the proton to travel between two detectors separated by a distance "L". Each detector produces an electronic pulse of very short duration (LaTeX Code: \\Delta t << L/v) when a...

In 1971 four portable atomic clocks were flown around the world in jet aircraft, two east bound and two westbound, to test the times dilation predictions of relativity. a) If the westbound plane flew at an average speed of 1500 km/h relative to the surface, how long would it have to fly for the...

In 1971 four portable atomic clocks were flown around the world in jet aircraft, two east bound and two westbound, to test the times dilation predictions of relativity. a) If the westbound plane flew at an average speed of 1500 km/h relative to the surface, how long would it have to fly for the...

Homework Statement Relativistic protons that have a certain speed "v" are selected by measuring the time it takes the proton to travel between two detectors separated by a distance "L". Each detector produces an electronic pulse of very short duration (\Deltat << L/v) when a proton passes...

Can anyone tell me what exactly do the variables "Time Dilation" and "Velocity of a fraction of the speed of light" represent (in this graph) from the lorentz contraction? http://www.fourmilab.ch/cship/figures/gr_timedial.gif Does the x-axis represent "v/c" or is it "v^2/c^2"? What does...

Homework Statement <Q1> “Super Ted”, a famous children’s TV cartoon character, has just leant of an evil deed carried out by “Texas Pete” who had opened a farm gate at A and let all the sheep out onto the train tracks and roads. It shows that everything was normal until Super Ted boarded...

The quotes below (in blue) are from another thread https://www.physicsforums.com/showthread.php?t=364893&page=5" , but since they are a slight digression from the topic of the original thread, I have decided to continue the conversation in this new thread. Yes, that it what I am talking...

From reading in this forum I have gotten an idea regarding the calculation of dilation between an accelerating frame and an inertial frame. It seems there are two methods I have heard of: A) An evaluation based on the sum of instantaneous or infintesimally short interval relative...

Let's suppose that I am the Captain at a space dock sitting in interstellar space. My crew decides to go on a trip in our ship, so they board and set off at .9c. t = t0 / sqrt( 1 - v^2/c^2 ), t0 = 1, v = .9c, therefore t = 1 / sqrt( .19 ) = 2.3 (approximately) So as they speed off, 1...

Hi, Just out of idle curiosity - why do we talk of "time dilation" in terms of special relativity when in fact it contracts which is the opposite? Is there a reason or is it just accepted usage?

I'm having a hard time understanding some things regarding the doppler effect. Please excuse my Microsoft paint diagram, I'm no artist. http://img686.imageshack.us/img686/3949/diagram.jpg http://img686.imageshack.us/img686/3949/diagram.jpg" Given this scenario, which...

I've really been trying to understand the concept of time being relative in special relativity. I keep hearing the example of a spaceship taking off from Earth and traveling 99.999% the speed of light. It is said that possibly 200 years could pass for an observer on Earth while only days could...

I read that the Sun will become a red giant and destroy the Earth in about 5 billion years. If this is correct, is there any possible way that a vastly advanced alien civilization that exists in a galaxy 6 billion lights year away could ever reach the Earth and make contact with human...

I was thinking, if time passage varies with speed would the speed of atoms random movement (temperature) affect time? For example, if the universe is expanding, as some predict, it will eventually reach a state where everything will reach very near to absolute zero, or maybe absolute zero. If it...

Ok,so I am a bit of a noob so go easy on me! i was having a chat recently with my uncle (whos an astro physicist here in the UK) and although he didnt really give me the time of day because he's a busy guy,he said that my idea wasnt too far fetched but to come back to him when its got a bit more...

Before anything, I must admit I am a novice here. I've only casually dabbed in physics here and there throughout college, so I'm far from having a thorough understanding on these matters. I'm posting this hoping for a more educated individual to discredit my own oversimplified insight into time...

A firecracker goes off in Houston, Texas. A time 0.0133 seconds later as measured by synchronized Earth clocks, another firecracker goes off in Great Falls, Montana 2400 km away as measured on earth. a. How fast must a rocket ship travel if it is to be present at both events? b. What will...

Homework Statement A clock chimes every hour, on the hour in it's rest frame, is it possible for an observer to measure the time between chimes less than an hour? Homework Equations t = \gamma t0 The Attempt at a Solution I understand that if an observer traveling in the frame S'...