Time dilation Definition and 999 Threads

Sometime in the future two men meet at a space port and they synchronize watches, one boards a spacecraft and goes on a round trip around the solar system, when he returns the two men compare wristwatches to find they have different times. Q. Do the two men still exist at the same time or not?

Experiment 1: Astronaut travels away from Earth at near the speed of light, then travels toward the Earth at near the speed of light. Einstein tells us she barely aged, but red shift/blue shift don't seem to agree with that. While traveling away, both Earth and astronaut observe each other...

With regard to relativity of simultaneity and the "block" universe and reflecting on the notion of skewed time slices associated with frames moving relative to each other, one observer sees one event a distance away (parallel to the direction of motion) occurring before another event a distance...

Why aren’t all the SR effects cumulative like Time Dilation? Why should the Space dimensional effect become null when v—>0 while the Time dimension does not revert back to the 2 frames being in sync if Space and Time are treated on an equal footing. Clearly, Space and Time are not treated on an...

In Box 2.4 of the book "Black Holes & Time Warps" by Kip S. Thorne, he explains gravitational time dilation using the equivalence principle. For this he uses an experiment thought analogous to the one used by Einstein in 1911 to postulate the existence of a gravitational Doppler shift, but...

Good day. I have read many books, forums, and articles, and watched many youtube videos, all in an effort to understand special relativity and time dilation. Or rather, more precisely, trying to find a valid explanation that does not result in contradictions and paradoxes, and if it does, one...

This example is worked out in the book, and at the beginning, they make the assumption that the muon is traveling at c, and then find the change in time from the Earth reference frame using delta t=100km/c. Then delta t is plugged into the time dilation equation on the left side and we solve for...

In this case, γ = 1/√(1-v^2/c^2) = √(1-0.6^2) = 0.8 However, I'm not sure if time observed by Earth is proper time or moving time. The definition of proper time in my textbook states that it is 'the time measured in a frame of reference where the events occur at the same points in space. I'm...

Hello, What I understood from multiple answers on different threads is that the effect of the time dilation is too small to explain the galaxy rotation curve. I was advised to do some calculations in order to see it myself. And this is what I would like to do but I need some help. - What is...

Summary:: Ideas for a novel I want to begin writing. Brainstorming ideas and need help with a certain concept. Any help is appreciated! Hello to you all, this is my first post, and I Google searched this astrophysics forum because I thought it might be a good place to begin asking for advice...

what is wrong with the thought experiment below?! If I consider a light beam going straight towards an observer in motion it makes it look the moving clock ticks faster, but if you use a light clock it makes it look like the clock turns slower. What am I missing here? “Two observers convene in...

The faster the relative speed or the more intense the gravitational field, the slower time passes. Does it make sense to ask what both have in common that affects time? Or does the question possibly only make sense in the context of certain theories, for example the LQG, where space and time...

It is possible to derive 2 contradictory time dilation equations. The first paragraph below describes the situation with Sally aiming a flashlight straight up and down so that Sally sees the light moving straight up and down and John is outside the spaceship and sees the light forming a...

If time for something approaching the speed of light will slow down and approach zero, then how is it that light itself can exhibit changes - the oscillation of the E and B fields? Is it because those fields are perpendicular to the direction of light travel? If so, then something other than...

if you could leave the planet, and wait a year in space... would you age much much faster than a person on Earth because the Earth was moving relative to you and you are out of Earth's gravity field [like a higher up clock]?

I have been able to prove to myself that, based on Einstein's two postulates and the the Pythagorean theorem, that time dilates. From here how do I prove that length contracts? (All of this observing a frame that is moving relative to the proper frame at uniform velocity.)

Hello there.About time dilation, could we provide a derivative of time in relation to one of the coordinates of the manifold we have taking time as a function and get something as a result?Or its integral?And about time dilation we have the formula that gives it between two clocks and an...

I’m having quite a bit of trouble understanding time dilation. What will happen if you orbit the Earth close to the speed of light, 1 h passes for you and due to time dilation 2 h on earth. So what will happen when you look at Earth in that hour. Since time passes 2 times faster there will it...

This probably has been asked before but i had a thought about the speed of light and time dilation. First off all i know the speed of light is constant and that it is the max speed anything can be but hear me out. So let's say a jet are traveling from point a to b in space with let's say 0,8c...

So basically i know almost nothing about physics but i have this one curiosity and i hope you can help me ahah. For what i understand if you could move at the speed of light time would stop for you and you would see the whole universe age in a blink of an eye. But what if you could stand...

I’m sure the resolution is something to the effect of “we can only apply special relativity in flat spacetime” but I’m hoping someone can explain in more detail. Disclaimer: I don’t know general relativity. So in a positively curved universe, if you keep traveling (let us neglect expansion)...

Earth moves through space in a certain direction at a certain speed. Moving faster slows down your clock while moving slower increases your clock. Does this mean that the direction your moving in has an effect on time dilation? In other words, if you move along with the earth’s initial speed...

OK this is a quote from the physics forum site - it is not mine. So the above quote says that there are two effects which alters the clock ticks, the GR effect and the SR effect for clocks aboard satellites. We all know that satellite are in free fall and for free fall there must be a steady...

Bob is standing on Earth and Alice is on a distant planet at a constant distance from Earth. Their watches are already synchronized in the following sense: Suppose Alice's planet is a light-year away from Earth. Bob emits a light signal to Alice at time t = 0 according to Bob's watch. When Alice...

Radio wave travels at the speed of light 3x10^8 (m/s) Converting the distance to meter: 1.3 x 3.1x 10^16 = 4.03x10^16m The time it takes in our Earth frame of reference is: 4.03x10^16m/3x10^8 (m/s) = 4.26 years The answer is B But wouldn't the time in light's frame of reference be 0 and it's...

Hi this is my first post the forum, nice to meet you all. I am trying to derive the time dilation formula following the image attached. However I am unsure of the algebra being used toget from the 2nd line of working to the 3rd line. Can someone please tell me what the name of the algebra...

The point of the twin paradox in special relativity is that the traveling twin experiences a real, frame-invariant effect in which the time evolution of all moving matter is slowed down. If you read a hundred articles and textbooks on SR, you'll see a hundred variations on the message that the...

Hey everyone, I have generated a nice little velocity vs time graph that I would love if somebody could help me put to use. I have marked data points on the x-axis for the Y-value for every second on the function. Just to be clear: X-axis = time in seconds & Y-axis = velocity in meters/second...

If time slows down near a black hole then doesn't it stand to reason that time is slower in our galaxy than inbetween galaxies. If that's the case, wouldn't our measurements of distant galaxies be over estimated do to time being faster intergalacticly. Would this time dilation help explain part...

Good morning I'm a total beginner in physics, but I recently started to read books and watch videos about cool physics stuff, like relativity. I heard that the closer to the speed of light you travel, the "slower" time passes for you. I'm talking about the fact that clocks in GPS satellites...

Imagine this question in 2 dimensions, time (t) and distance (x), that is (t,x). Alice (A) is at the origin, x=0. Bob (B) begins at x=c. Thus we have A(0,0) and B(0,c). Both Alice and Bob send a light signal towards the other but let's say the signal changes colour every second by the colours of...

I was absent for a while due to personal constraints but I did keep myself busy with the Time dilation equation some member sent me a while back. I decided to set a time limit for myself to learn and understand time Dilation and length contraction, which must be before December 2020, or I will...

I am more confused by the theory of relativity as I start thinking about it. I have a question and it might sound silly but please, correct me if I am wrong. Suppose, A and B are twins where A is at the Earth, and B is moving on a spacecraft at a speed near to the speed of light. In this...

Thank you in advance for your replies. While reading about special relativity I started thinking about how time dilation might affect temperature. Since temperature is really the jiggling motion of molecules, does time dilation affect temperature by slowing down the jiggling motion? Or...

I think this should be t'= Lorentz factor* (1+v/c)t, but that doesn't make sense to me.

I've been trying to understand gravitational time dilation by considering a light-clock of length ##l## undergoing an equivalent acceleration ##a## from rest along the direction of the bouncing light pulse. I find that the time ##t## that the light pulse takes to travel to the forward receding...

Ok so here's my idea,it came to me while watching a record album spin on my turntable(I believe it was Dark Side of the Moon). Technically this exp. could be done now but the results would take a while. You take a disc of some super strong material attach it to a ultra high RPM motor and put...

According to the theory, every mass has a Schwarzschild radius associated. Any object whose radius is smaller than its Schwarzschild radius is called a black hole. So in principle is possible to create mini-black holes, it is just a fact of matter condensed. Those mini black holes have their...

Do photons, I'm not sure how to express this, "experience" time? Since they move at the speed of light does time not exist for them? If time does not exist, how is it possible for anything to happen to them. If interacting with matter requires a change in their condition, how can a change in...

Hi, Could you please help me with the queries below? Question 1: A GPS satellite is moving faster than the earth, for every day on Earth the clock on the satellite shows one day minus 7 microseconds due to time dilation due to special relativity. However, since the Earth's gravitational pull...

[Wow - special relativity is amazing but boy is there a lot to get your head around! We're only being introduced to it as a taster of college courses but the few lessons we've had have left me with more questions than answers; most fascinating topic yet, I think!] Unfortunately I've tackled a...

Firstly, I am a Mechanical engineer working in the aerospace industry and I know very little compared to the collective community here and my formal education had to do with practical and basic stuff, so apologies if I’m overlooking a basic principle or something. my idea: what if we launched a...

how to equal the equation: E = mc2 and the Time dilation equation

This video here <link deleted> 8.50 to 9.50 minutes , shows an apparent contradiction in time dilation, in the "twins paradox" the clock that is accelerated is relative, i.e. from Earth the spaceship moves but from the spaceship the Earth moves. I know time dilation is a real thing used in real...

Suppose there are two clocks. Clock B is moving with a speed of ##v## relative to clock A. Then clock A is moving with a speed of ##-v## relative to clock B. Let ##t_0## be the time interval for two events in the framework of clock A, while ##t## be the time interval for the same two events in...

In the Lagrangian (L1) point between two hypothetically massive (and close) objects , is gravitational time dilation effect summed or canceled, or something else?

Shouldn't we question why cosmic voids are expanding but not galaxies?

The is a question about gravitational time dilation and escape velocity. As others have pointed out, you may use escape velocity to calculate gravitational time dilation in a gravitational field. (Interestingly, you can't use gravity to calculate gravitational time dilation, which makes...

with distance between planets as 4x10^8m measured by you on the ship My attempt: t' = γ(t - ux/c^2) γ = 5/3 u = 0.8c t = 0.9s x = 4x10^8m answer is: -0.278 Therefore not possible My question is what if we traveled rightwards, from p2 to p1, would the answer change? Should my above information...

For instance, if a stream of muons were released from a box near a massive object and traveled on a straight path slowly (at a non-relativistic velocity) away from that object, a faraway observer would notice that the particles would take longer to decay than a muon typically would in empty...