Dilation Definition and 1000 Threads

This question concerns a paradox I've come up with in GR. If somebody could tell me where it breaks down, I'd be much obliged. Thank you! Assume there is spaceship A hovering above a black hole, and spaceship B further away from a black hole The black hole, A, and B are all lined up. (The...

i'm 21, my bf is 20, but my parents won't allow me to marry a younger man...so is there anyway, i can use the idea of general relativity to slow down my aging relative to my bf, so that we both reach 25 at the same time? here's what i know so far: i understand that if I'm one floor above my...

So what I've heard so far is that if you're in a spaceship and you're moving at a speed close to the speed of light relative to the Earth then what seems like 1 hour for you could be something like 1 million years for people on earth. This made sense to me until I realized you're moving relative...

I'm going to use the time traveling twins example to try and explain the crossroads I'm at with special relativity. The one twin is back on Earth while the other twin is traveling to a star 10 light years away at .8c. We calculated how long it would take on the earth-star frame of reference, it...

All, I am familiar with the concept of orbiting a black hole without entering its event horizon as a means of time travel. Does anyone have any research on this matter, or know of any papers which deal with this concept. I would really like to explain this concept to a colleague and additional...

I was just reading about the experimental proof of time dilation using some atomic clocks on aeroplanes. Which got me thinking... Consider a rotating disk. Say it is a few hundred metres radius (although its size makes no difference to this question, it makes it easier for me to visualise)...

Dilation & Contraction--First Post Hello! I am a brand-new member here (please be gentle and basic). I have been listening to a course on special relativity and general relativity—the lecturer is Dr. Richard Wolfson. I have no serious mathematical background but would like to have a much...

Hi All, how is the age of universe calculated ? i read a few articles/wiki etc and its estimated to be roughly 13.7 billion yrs old. Have we considered the time dilation effect here ? cause we are measuring the electro magnetic radiation traveling in an expanding universe and in an...

I were trying to figure out the "logic" why gravitation (acceleration) causes time dilation. While at "velocity time dilation" its because (e.g) light in light clocks must travel longer distances. As seen on those pics: http://en.wikipedia.org/wiki/File:Time-dilation-001.svg...

Help me settle an arguement: Say you have two clocks, one moving at 2/3 the speed of light (for explantory purposes called "A") and another at rest ("B"). Which clocks tics faster?

Hello all, I am new to the Forum and have no formal Physics training. I have an interest in the subject mainly due to other pursuits. I am reading Joe Haldeman's The Forever War. I would definitely recommend this book to anyone with an interest in Time Dilation or Humans vs Aliens at...

Homework Statement An astronaut traveling at 0.90 c, with respect to Earth, measures his pulse and finds it to be 70 beats per minute. a) Calculate the time required for one pulse to occur, as measured by the astronaut. b) Calculate the time required for one pulse to occur, as measured...

Homework Statement This is problem 5.2 in Kittel's Introduction to solid state physics: Estimate for 300 K the root mean square thermal dilation for a primitive cell of sodium. Take the bulk modulus as 7\cdot10^{10} [unit]. Note that the Debye temperature 158 K is less than 300 K, so that...

Suppose a stationary observer was watching a spaceship travel near the speed of light and close to a massive black hope so that time dilation from the relative velocity and gravity of the massive object are significant. Assume that the ship is moving at 0.866c so that for every hour that...

Can gravitational field strength cause time dilation. as G.F.S on Earth is 10 N/kg and on moon it is 1.6 N/kg. so will a clock on the moon surface tick slowly for the observer on Earth or not?

Homework Statement A space traveler takes off from Earth and moves at speed 0.81c toward the star Vega, which is 26 ly distant. How much older will Earth observers calculate the traveler to be (according to her) when she reaches Vega than she was when she started the trip? Homework...

We have two clocks, A and B. B is moving with constant velocity with respect to A. From the reference frame of A, B is running slow. From the reference frame of B, A is running slow. Why is this not a paradox?

An airplane travels at a constant speed v for a distance of 3000km as measured by a stationary observer. The pilot measures the flight time to be \Delta t and the stationary observer measures the flight time to be \Delta t'. (Then I solved the first part of it, showing that \Delta t' > \Delta...

Hey all, I'm having a bit of trouble with this problem. Two events occur in an inertial system K at the same time but 4 km apart. What is the time difference measured in a system K' moving between these two events when the distance separation of the events is measured to be 5 km? I though...

didn't time dilation concept known before einstein relativity theory? there were ancient story saying that time runs differently on different planes of existence. i will relate one of ancient hindu mythology in which time dilation was referred. Story of King Kakudmi and his lovely...

Homework Statement The Apollo astronauts returned from the moon under the Earth's gravitational force and reached speeds almost 25,000 mi/h WRT Earth. Assuming (incorrectly) they had this speed for the entire trip from the moon to Earth, what was the time difference for the trip between...

Homework Statement The Apollo astronauts returned from the moon under the Earth's gravitational force and reached speeds almost 25,000 mi/h WRT Earth. Assuming (incorrectly) they had this speed for the entire trip from the moon to Earth, what was the time difference for the trip between...

Homework Statement An athlete has learned enough physics to know that if he measures from the Earth a time interval on a moving spacecraft , what he finds will be grater than what somebody on the spacecraft would measure. He therefore proposes to set a world record for the 100m dash by...

Imagine two spaceships a distance z apart both moving with the same constant acceleration a. The trailing spaceship shoots a beem of light which will be redshifted by an amount \frac{\Delta \lambda}{\lambda_0} = \frac{az}{c} (assuming that \frac{\Delta v}{c} is very small). Due to the...

I know that this is a very basic question but what is the correct formula for time dilation? In Wikipedia etc. I read {t^'} = \gamma {t} or at least \Delta{t^'} = \gamma {\Delta{t}} ; yet in this...

I've been twisting and turning my brain to figure this out but I need some explanation: Following the twin paradox, I've learned that aging does occur, but I thought that time dilation was relative to the observer and the 'observee'? So if aging does occur then doesn't that mean that there is...

Firstly, just to confirm, the value for velocity in the equations to calculate time dilation is the speed at which two things move away or towards each other? So if some object was moving parallel to the other, they would measure no time dilation on each other? But if one was moving...

Homework Statement Now, suppose the student wishes to bring back some ice cream from the restaurant for her friends at school, but since it is such a hot day, the ice cream will melt away in the car in only 5 minutes. How fast will the student have to drive back to get the ice cream to her...

Simple question, but I don't expect a simple answer. What are the causes of Time Dilation relative Velocity? I can swallow the fact that gravitational fields can change the speed of time locally. But velocity? What the process behind Time Dilation related to velocity? I can never...

If you throw up a clock in a field of gravity and it falls back down, will it show the same time as a clock that stayed at the surface? In other words, will the gravitational time dilation of the stationary clock exactly equal the sum of the smaller gravitational time dilation of the other clock...

My understanding is that SR time dilation and Lorentz contraction are flip sides of the same coin. The two always occur together, never separately. That is implicit in spacetime diagrams. I think this duality requirement is necessary so that light always travels at the speed of c in every...

Is it possible that time dilation has a direct corelation in the production of gravity. Markonline

Hi all, I am not so good in physics. Plz forgive me if i am totally wrong. However, i just want to understand the time dilation thing. I referred the net, but couldn't get a convincing answer. Please explain how the time in two clocks in different inertial frame of reference can show...

I am not interested in knowing the detailed calculation but would be more than happy if you could just answer the simple questions I put. Suppose in a Universe There are just two peoples A and B in their space ship. Now suppose they are initially at rest and both have a clock that now shows...

First, a simple scenario to set our expectations: Consider a "stationary" massless non-relativistic test particle in empty space. We'll call the particle "P". At a very large proper distance to the cosmological "west" of P there is a neutron star, at proper rest relative to P. Let's call...

hypothetical: If I were to spin with my arms outstretched, with the tips of my fingers moving at (or near) the speed of light the center of my head would therefore not be moving at all. Would the centre of me age faster than the extremeties?

So finally I can understand the time dilation principle. Correct me if I am wrong but here is how I understand it: If 2 twins on Earth conducted an experiment of time dilation, twin 2 hops into a rocket ship and flies around the Earth at a high rate of speed for years. When they meet up again...

Say there were a black hole near Earth (either recently found or created) that we could travel to. With similar technology available to us today, if we built a spaceship and came as close to the black hole as possible without the effects of gravity breaking the ship apart or ripping our bodies...

Is change possible without time? Also is time possible without change? What is the correlation between the two and how does time dilation affect change?

This may be an easy answer for AtsroPhys vetrans. But I'm assuming since the doppler effect of an accelerating galaxy causes reshift, then the time dilation from a gravitational field would do the same. This is referring to very powerful fields, and also to redshift in all waves (not just...

Can anyone prove the twin paradox

I have a problem with time dilation... You have all heard the story where there are two identical twins and one goes on the spaceship and flies around at nearly the speed of light, comes back, and is still young while everyone on Earth, including the twin who stayed there, are old. But...

Homework Statement At what speed does a girl need to travel, if her journey begins in 2009 and she wants to come back two years older in the year 2018. ^^^Can someone please check my answer. I am new to the topic Homework Equations T = To / sqrt(1-u^2/c^2) The Attempt at a Solution...

I need someone to resolve this paradox for me. Before I start, here are the basic ideas: Okay, so every moving particle has a DeBroglie wavelength: E=hc/\lambda. This also means that each particle has a frequency: E=hf So it also has a period: E=h/\tau So any given mass has a DeBroglie...

Homework Statement in 1962 a person orbited the Earth 22 times, the press stated that each orbit he aged 2millionths of a second less, then if he remained on earth. a.assuming he was 160km above the earth, in a circular orbit, determine the time difference between on Earth and the orbiting...

Hi. I recently bought A Brief History of time by Stephen Hawking and has since been very intrigued by the whole idea of time dilation. I've been searching on the internet and reading a lot about it and it is beginning to make sense :) However I have a problem that I just don't seem to get...

Homework Statement The Star Alpha Centauri is 4.0 light years away. At what constant speed must a spacecraft travel from Earth if it is to reach the star in 3.0 years, as measured by the travelers on the spacecraft . Homework Equations Length Contraction: L = Lo*(sqrt(1-(u2/c2)))...

I have a question about gravitational constant. Gravitational constant is dimensionfull constant but say time is is affected by gravitation causing gravitational time dilation. So the definition of second is local. Does it means that gravitational constant is well defined locally but not...

Hi all, 1. the max. speed of waves in the air is the speed of sound. it's caused by the physical limitation - changes in the air fabric (particles) can't propagate faster in it. 2. so I was wondering, whether the max. speed in our space isn't limited by the max. (indivisible/atomic) change...

I've been reading about how gravity affects light and time. However, I'm a little confused about the details. Does light lose energy and decrease in frequency the further away it gets from Earth? If so, this means that the frequency of light (the number of light waves per second) increases...