Time dilation Definition and 999 Threads

I am extremely confused with why time dilation is different from what I've read about traveling at speeds near that of light. I think that I am mixing up two concepts. What I understand is that due to time dilation, both observers would view the other's clock as running slow as long as both...

Does the relative motion of a thing slow down the relative motion of a thing? Hope that makes sense or you can work out what I mean.

I want to know that if one sends a radioactive material in a spaceship at high speed and bring it back, do we find that the radioactive material has decayed slower than it would on Earth or the same rate? As radioactivity doesn't depend on the Coulombic interaction (photons), rather other...

The way I've been reading it, elliptic geometries are due to a positive Gaussian curvature, while hyperbolic geometries are due to a negative Gaussian curvature. Do local saddle curvatures mean local time dilation and length contraction, or do they mean local time acceleration and length...

I'm looking for another derivation of time dilation which does not involve moving clocks or mirrors... I feel like those aren't very clear - is there any other way time dilation has been derived? thanks

Homework Statement Two atomic clocks are synchronized. One is placed on a satellite which orbits around the Earth at high speeds for a whole year. The other is placed in a lab and remains at rest with respect to the earth. You may assume both clocks can measure time accurately to many...

I like astrophysics,so i read books relating to it.I am also determined to make my career in the same.At present i am reading a book ,which includes brief about Einstein's 'Relativity and special relativity' theory.It also explains to some extent the 'Twin paradox' and 'Time dilation'...

hi friends i am really confused with time dilation ... Time is quantity which is defined by us, and it will be always constant then how einstein said the time will dilate when we travel at the speed of light.. thank u...

It is a thought experiment and based on time dilation. It goes like.. consider a cab moving with a speed close to light.Also the cab has been divide into two equal halves by a glass wall. there are two individuals in cab one in each part of the cab divided by the glass wall.One is very old...

Let's say I had built a machine that is able to slow down time (Travel to the future) by one eighth. If the object creates a non rotating sphere using lasers and it is able to accomplish this task, would the time dilation be stronger in the machine or out of the machine?

I imagine I have two clocks that are synchronised and are sitting a long way from a large massive body. I hold on to clock A and let clock B fall towards the mass. Let's assume that the falling clock B gets close to the massive body but somehow misses it, swings around and travels back to me...

Are these really just two ways of explaining the same thing?

This question is in regard to special relativity. From my rudimentary understanding, concerning the twin paradox, if one twin leaves traveling near the speed of light and returns, he will find himself younger than his twin who stayed behind. Hence, the effect of time dilation is permanent...

I just got my first official introduction to relativity in my textbook (I'm equivalent to a high school senior student). It is part of a chapter on modern physics.It first mentions the two basic postulates and then briefly introduces what length contraction, time dilation, increase in mass...

A moving clock is observed to run four times more slowly than an identical stationary clock. What is its speed relative to the frame of the stationary clock? I'm wondering which equation should I be using for this? Thanks

hi all I was thinking abt the time dilation derivation thought experiment a flash of light shone on a mirror(imagine a window on the left and motion of vehicle towards right), transverse to the direction of motion.according to the derivation the person in the rest frame,P would see the light...

From https://www.physicsforums.com/showthread.php?t=40391 in gravitational time dilation. At the center of neutron star PSR J1614-2230 at 1.97 SM mass of Sun 1.9891×10^30 kg mass of PSR J1614-2230. 4 ×10^30 gravitational constant = 6.67300 × 10-11 m3 kg-1 s-2 radius(rough estimate) =...

I recently read that the center of a quasar does not or almost doesn't experience time dilation, can anybody help me understand this more? The text didn't help much.

Suppose, there are two inertial frame first is in motion with constant speed and second is motionless. We can say that two frames are relatively in motion with each other with constant speed. So time would slowdown for each frame referenced by other frame. But after some long journey first frame...

I (think I) understand that: 1. With the Schwarzschild metric, the ratio of proper time to coordinate time decreases ("clock runs slower") with decreasing radial distance. (And ratio of proper distance to coordinate distance increases.) 2. The geodesic path followed by a freely falling...

While gravitational redshift refers to what is seen, gravitational time dilation refers to what is deduced to be "really" happening once observational effects are taken into account. When using special relativity's relativistic Doppler relationships to calculate the change in energy and...

If one wants to calculate the elapsed time from the perspective of an object A moving at velocity, v, for time, t, relative to a stationary object B, all you have to do is calculate: \int_{t_o}^{t_f}\frac{t}{\gamma} Of course, \gamma has no dependence on t because v is constant, so we get...

Homework Statement In which of the following situations is the time interval between the two events in one frame equal to (LORENZ FACTOR (special y symbol)) multiplied by the time interval in the other frame. explain briefly. a) A muon is created (event #1) high in Earth's atmosphere and...

Homework Statement The nearest star to Earth is Proxima Centauri, 4.3 light-years away. At what constant velocity must a spacecraft travel from Earth if it is to reach the star in 3.7 years, as measured by travelers on the spacecraft ? How long does the trip take according to Earth...

Here's a scenario: A crew travels through the Universe in a spaceship capable of 100% light speed. Relativity states that anyone inside of said craft will experience time dilation, possibly to the point of time coming to a complete stop for the crew/passengers. But time passes much quicker...

I have been wondering this ever since I was in elementary school and I am hoping for an answer. The time dilation equation for general relativity is time dilation=e^(gh/(c^2)). This applies to any object that has mass, and I am wondering if it also applies to the Big Bang (which has mass). I...

I have some questions about time dilation I not really understand to come further (and I find it all very interesting). 1) I understand that the situation between A (standing still) and (moving) B is SRT symmetric, so if they compare clocks they both see the same time. In fact there is no...

Hi, I've been listening to a Professor Jim Al-Khalil's scipod on time travel. I think this guy is bloody excellent by the way. http://reader.mac.com/mobile/v1/http%3A%2F%2Fwww.jimal-khalili.com%2Fpodcast%2Fjim.rss Anyway, He said to an observer on the Earth a clock on a...

As I currently understand it from the point of view of an observer falling into a black hole it takes a finite time to cross the event horizon and reach the singularity. From the point of view of a far away observer the person falling into the black hole never actually crosses the event horizon...

Special relativity homework question time dilation 1. Homework Statement You are a passenger on a brand-new spaceship that travels at 95% of the speed of light, i.e., v = 0.95 × c. The spaceship is bound for the star, Altair, at a distance of 17 light years from Earth. If the spaceship...

Homework Statement You are a passenger on a brand-new spaceship that travels at 95% of the speed of light, i.e., v = 0.95 × c. The spaceship is bound for the star, Altair, at a distance of 17 light years from Earth. If the spaceship departs on your 21st birthday, at a speed of v = 0.95c, how...

Thought experiment: Say for instance that a Baseball game is being played out on a planet that is orbiting the outer edge of a black hole. You, from deep in space away from any gravitational source, are watching this game from a powerful telescope. The batter comes up to bat; the pitcher...

So, according to my understanding, if we leave Earth and travel close to speed of light and then come back we may have time dilation (there will be one year for us, but 10 years for the people on Earth). But how does this work as long as there is no frame of reference? Why can't we consider...

For instance you have time dilation in special relativity which is said to be due to something moving faster than something else relative to it. You also have the time dilation in GR where time speeds up the further away you go from a body such as the Sun, Earth, etc. Now could it really...

My idea of explaining time dilation to others (average people) was : see a light wave as the time, person A standing still sees the time (light wave) passing, person B moving sees lesser time passing when going in the direction of the light wave (while "looking" to the light wave) because he is...

Does relativity theory make a connection between gravitational time dilation, and the time dilation experienced at high velocity?

A clock falling towards the event horizon of a black hole would appear slowed down to the point of being frozen in time (or almost). But I'd like to understand properly what happens to the length contraction experienced by an observer falling together with that clock. Would he experience...

I just had a quick question on time dilation that I'm stumped on. There are three observers: two are traveling on separate ships traveling close to the speed of light (their speeds are the same) in opposite directions parallel to each other. One observer is standing still on a space station...

As far as I understand, time dilation corresponding to redshift has been confirmed for distant supernova. However, galaxies are being detected only 480 million years after the bigbang at redshifts of around 10 or more. Does this mean they took less than 45 million years to form in real time?

https://www.physicsforums.com/showthread.php?p=3577768#post3577768" has caused me to question my assumptions. If a target of observation is moving at relativistic velocities but its distance does not change wrt the observer, is it observed to be experiencing time dilation? Alice stands at...

Suppose there are two observers separated by distance of 2 light minutes. They have 2 identical clocks, which are synchronized. Suppose one of the observer shoots a missile at 3 PM. The other observer, who is able to see him, will observe that the missile has been shot at 3.02 PM. According to...

I propose an explanation of the special relativistic time dilation and calculation of its factor in terms of the difference in observational times for incoming and receding objects, based on the following thought experiment: Imagine a spaceship coming from planet X to Earth with velocity V...

Sorry for yet another time dilation question. I have a couple example problems that I can't seem to explain. 1) A ship leaves the Sun and heads for Earth at 0.5c. An observer on Earth would see the the light from the sun take 8 min, and the ship take 16 min. The pilot's clock would show it...

I'm working on a simple time dilation problem: Astronomers discover a planet orbiting around a star similar to our sun that is 20 LY away. How fast must a rocket ship go if the round trip is to take no longer than 40 years in time for the astronauts aboard? I have set up the problem: T=...

As time-dilation is stated in STR, 1.) it is an intrinsic decrease in rate of passing of time, with relative motion(radioactivity half-life change). 2.) it is non-directional, that is, time-dilation depends only on the magnitude of relative speed. Now, please consider the following...

Hi! :smile: Need some help here. Can we perceive time dilation and length contraction in a non-inertial reference frame? If we observe a reference frame experiencing acceleration close to c, do we see the same effects as in an inertial reference frame?

Homework Statement Plans are made to send a spaceship from Earth to a nearby star 10 light-years away and at rest with respect to Earth. The light support systems within the spacecraft will last for a year. (a) what is the minimum speed of the spacecraft relative to the Earth-star system if...

After a fairly long time of thinking I had a decent grip on the concept of time dilation, it has suddenly occurred to me that I don't. My issue is with the concept of the aging twins thought experiment (or whatever it's called) where if one shoots off at some comparable speed to the speed of...

Relative some arbitrary point in Earth’s orbit around the Sun, does Earth experience varying degrees of time dilation specifically from gravity? With Earth's orbit around the sun being elliptical I wondered if Earth experiences varying degrees of time dilation caused by the suns gravity (or...

Homework Statement Anna is on a railroad flatcar moving at 0.6c relative to Bob. Her arm is outstretched in the dirction the flatcar moves, and in her hand is a flashbulb. According to her wristwatch, the bulb goes off at 100 ns. This even according to Bob differs by 27 ns. a) is it earlier...