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3
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2answers
200 views

Sending someone into the future using the sun?

Ok so for starters, i am not nearly as smart as the least-smart person on here, but I have been reading a lot about all sorts of stuff. We now know that the ability to "send" someone to the future is ...
1
vote
2answers
83 views

Negative Gravity Fields and Time Dilation [duplicate]

Question: Some physicists believe that it is possible to have negative mass. My questions is would this negative mass create a negative gravity field, exerting a negative force on positive masses? And ...
53
votes
8answers
12k views

If the speed of light is constant, why can't it escape a black hole?

When speed is the path traveled in a given time and the path is constant, as it is for $c$, why can't light escape a black hole? It may take a long time to happen but shouldn't there be some light ...
2
votes
2answers
63 views

Time dilation: time shortest where events occur at same place?

In his book Simply Einstein Richard Wolfson describes time dilation this way: "The time between two events is shortest when measured in a reference frame where the two events occur at the same place." ...
0
votes
0answers
36 views

How is gravitational time dilation different from time dilation due to differences in speed? [duplicate]

This is what I understand from what I've been reading online: In the derivation for the gravitational time dilation equation, $$t = t_0\sqrt{1-\frac{2GM}{rc^2}}$$ we use the special relativity ...
2
votes
2answers
62 views

Question about time dilation for a traveler that can reach the “edge” of the universe

I thought I understood time dilations but I feel now confused. Imagine somebody traveling in a rocket near the speed of light, close enough so that he will be able to reach the edge of the universe in ...
0
votes
1answer
62 views

About the earths core being 2 1/2 years younger than the surface

In April's addition of New Scientist there is an article on page 10 by Jacob Aron. This article describes how Earth's core because of time dilations could be 2 1/2 years younger than it's surface. Or ...
0
votes
1answer
46 views

special relativity mirror experiment

There's an experiment in special relativity that involves a light source and a mirror, both placed in a moving object. It is used to derive the time dilation equation. I'm having serious doubts about ...
1
vote
1answer
206 views

Time Dilation Question

I know physicists don't often like to hear about "photon's frame of reference", so I apologize in advance :) If the time dilation at the speed on light is infinite, it should mean that if Bob is ...
0
votes
0answers
43 views

Negative Mass's Effect on Gravitational Time Dilation [duplicate]

When I was playing around with the equations for Gravitational Time Dilation, I discovered that when a negative value was plugged in for $M$, the equation gave the exact same answer, and it would ...
80
votes
1answer
5k views

Is there such thing as imaginary time dilation?

When I was doing research on General Relativity, I found Einstein's equation for Gravitational Time Dilation. I discovered that when you plugged in a large enough value for $M$ (around $10^{19}$ ...
1
vote
1answer
43 views

Traveling slower by traveling in opposite direction as the Earth rotates

I know that if I were to travel fast, the time would pass by fast for me. But if I were to travel fast in the opposite direction of the earths rotation while I'm still on earth, would the time pass by ...
0
votes
1answer
65 views

Is the time dilation experiment for real?

A popular experiment is described in books on special relativity, that claims that an atomic clock was flown at high speed and later compared with a similar atomic clock on earth, and it was found ...
0
votes
1answer
69 views

Why do we not apply length contraction when finding out the time taken for objects moving at relativistic speeds?

I was going over a question on my own, then I took a brief look at the solution...it's basically about A rocket has a proper length of 250 m and travels at a speed v = 0.950c relative to the Earth. ...
1
vote
0answers
20 views

Time Dilation for a photon [duplicate]

Does a photon experience any time. Since a photon is massless and hence travels at (c) then it should suffer infinite time dilation, and hence shouldn't experience no time?
0
votes
1answer
41 views

Funny Time Dilation Relation

Today I was curiously calculating/comparing the times of moving observers and the time recorded by a corresponding stationary observer using Einstein's time dilation equation as detailed in Special ...
-1
votes
2answers
44 views

can time dilation be used to determine if an object is moving

I know that movement is only relative to another object, but as you move faster you also experience time dilation, correct? So if one body is moving faster then it should have a dilation of time, ...
0
votes
1answer
16 views

Would Gravitational Time Dilation still apply between two gravitational sources?

As explained on this Wikipedia page, when an object is experiencing strong gravitational forces, time passes slower for it. If, in theory, you had two objects exerting the same amount of gravitational ...
1
vote
1answer
84 views

How is time dilation consistent between both observer?

There is a special variant of time dilation paradox bugs me. Imagine there are 2 small spaceships moving toward each other in constant speed. Each ship has an observer on-board. According to both ...
1
vote
2answers
39 views

Why do relativistic wormholes have to be brought together to make a “time machine”?

In "From wormhole to time machine: Comments on Hawking’s Chronology Protection Conjecture" by Matt Visser (http://arxiv.org/abs/hep-th/9202090), he summarizes how "time machines" may be created from ...
5
votes
4answers
149 views

Would time speed up near a large body of negative mass relative to observers in micro gravity?

Time tends to slow down near objects with large amounts of positive mass relative to observers in micro gravity. Considering that negative mass is the opposite of normal mass and would time tend to ...
1
vote
1answer
51 views

How does time dilation occur due to velocity and gravity [duplicate]

I am trying to understand and clarify the way time dilation occurs due to general and special relativity and for which reason. In the case where an object is approaching a planet in free-fall how does ...
1
vote
1answer
36 views

Is Snell's law a product of Gravitational Time Dilation?

Due to the proximity of atomic structures in a solid liquid or gas, does the gravity of these atoms warp time enough to cause light to move slower from the perspective of an outside observer?
0
votes
0answers
36 views

Why doesn't time dilation resolve entanglement

I'm a layperson who has read bits about relativity and quantum mechanics over the years, so this is a naive question, but I can't see where My reasoning fails... Photons travel at the speed of light, ...
0
votes
0answers
19 views

Simple Question About Repulsive Potential Field Time Dilation

A space-time with a point mass gravitational potential given by $\Phi(r)$ has a metric described by, $$ds^2=-\left(1+\cfrac{2 \cdot \Phi(r)}{c^2} \right) \cdot c^2 \cdot dt^2+\left(1-\cfrac{2 \cdot \...
0
votes
1answer
44 views

Time-dependent time dilation for circular orbits around a Schwarzschild black hole?

Take two clocks, one in a circular orbit around a Schwarzschild black hole and another with a distant observer. The time dilation factor between the two clocks is said (at https://en.wikipedia.org/...
0
votes
2answers
97 views

Are gravitational force and gravitational time dilation proportional?

Particles in gravitational fields are subject to gravitational time dilation. The closer a particle is near a gravitational source, the slower is running its clock. I would like to know more about the ...
0
votes
0answers
22 views

does falling towards blackhole make universe move faster? [duplicate]

If you fall into a blackhole would you begin to see the events in universe happening faster and faster as you move towards the hole? Also if you survive the fall through the event horizon as seen ...
5
votes
0answers
63 views

Radiative equilibrium in orbit of a black hole

According to Life under a black sun, Miller's planet from Interstellar, with a time dilation factor of 60,000, should be heated to around 890C by blue-shifted cosmic background radiation. How they ...
1
vote
4answers
229 views

Rapid acceleration does what to inertial frame clocks?

I'm 10 light years from Earth and see Earth's clock/calendar reading 2000, including light travel time. In other words, I assume it's 2010 on Earth, but what I actually see is the year 2000 due to ...
0
votes
0answers
39 views

Is there a relation between time dilation and (relativistic) mass increase?

I noticed that what once called relativistic mass increase and now is called energy increase is ruled by the same formula the Lorenz factor of time dilation? The formula is too particular to suggest ...
0
votes
1answer
68 views

how long will take for an astronal travel in near lightspeed in his point of view

I always had a question about relativity. Suppose an astronaut in orbit Saturn just must reach earth fast as possible. Your ship can travel at any speed between 0 and the speed of light. the distance ...
0
votes
1answer
179 views

Does Inertial time dilation demonstrate that Time is not a dimension? [duplicate]

If time is a dimension and 'now' simply an expression of your position with respect to that dimension, the progress of any object along that dimension should remain in step with all other objects. By ...
1
vote
0answers
15 views

A Question about Time Dilation and different observers [duplicate]

This is a question about time dilation and different observers. Say you had two observers. One on earth and the other one traveling around 20% of the speed of light. The observer on earth will age ...
0
votes
2answers
34 views

Time dilation when an object moves [duplicate]

Why does time dilation happens when the object moves, is it just because the physical processes, in the moving objects, happens slower? (this video suggests this: https://youtu.be/Ci4L6myFFng?t=224) ...
0
votes
1answer
55 views

3 points in space, relative motion, and the speed of light

I'm new to thinking about relativity, as well as phenomena related to the speed of light, time dilation, length contraction, simultaneity, etc. I am pondering a paradox. Assumptions: Motion is ...
0
votes
1answer
51 views

Spacetime Mercury vs Earth

What is the time dilatation of the planet Mercury compared to Earth? Can a person survive on the dark side of Mercury in the In the L2 position to Mercury and the Sun?
0
votes
0answers
30 views

What would you see standing on black hole just above the event horizon ? Will you look through past and future of the universe? [duplicate]

I am trying to imagine view from my house window if it was built on the black hole;) .... Of course I am joking. If time near event horizon slows down with respect to rest of the universe. I could ...
-8
votes
1answer
81 views

Explaining The Quantum Mechanics Weirdness [closed]

Academic replies only; I would like feedback on this, so yes i am asking you to poke holes in it, it is about explaining the time weirdness of quantum mechanics and how particles behave. When the ...
0
votes
0answers
40 views

complete layman trying to understand time relativity [duplicate]

I am trying to understand intuitively why time slows down as speed increases. I have watched many pseudo-documentaries explaining the concept, but I cannot get at the core of the explanation. The ...
1
vote
1answer
42 views

Near light speed space travel to more than one star and back to earth?

I'm afraid this one is kind of a yes or no question, because I think I would get lost in the discussion of metrics, etal. As a layman, I get that if you travel fast enough (by accelerating and ...
0
votes
2answers
72 views

Time Dilation diagram on wikipedia

The wikipedia article on Time Dilation (http://en.wikipedia.org/wiki/Time_dilation) has an explanation involving the following two diagrams: I have some problems with these diagrams. In the second ...
42
votes
5answers
5k views

What is time dilation really?

Please will someone explain what time dilation really is and how it occurs. There are lots of questions and answers going into how to calculate time dilation, but none that give an intuitive feel for ...
0
votes
2answers
90 views
-1
votes
3answers
100 views

How time dilation happens by velocity?

i got many explanation and proving that relative velocity causes time dilation. Einstein's moving light experiment proves it. but that is a clock works with light detector. as detecting the light gets ...
0
votes
1answer
32 views

Time dilation in a sphere of gas of constant density

If you have a sphere of gas of constant density, would something in the center of this gas experience time dilation relative to someone in empty space (not just someone outside the gas, but someone in ...
0
votes
1answer
114 views

Does time and time dilation exist in a black hole?

Since being near stronger gravitational fields causes time dilation, can this be generalized to the region beyond the event horizon? i.e , is it meaningful to say that someone outside the black hole ...
1
vote
0answers
39 views

From which reference frame is the time dilation factor measured?

I do not know much physics so please try to answer as simply as possible. I am probably confused but I recently learned that in Special Relativity (you can tell that I don't know much physics), the ...
5
votes
1answer
96 views

Two places having same gravitational acceleration - Do they also have same curvature of space time?

If there are two places (possibly on/above two different planets) having same gravitational acceleration (g), would it imply that the two places have same extent of space time curvature and will have ...
-1
votes
1answer
160 views

Time dilation confusion? [duplicate]

If I understand the theory correctly, time dilation causes a moving clock to tick slower than a stationary clock. If clock A is moving relative to clock B, then clock A ticks slower. However, ...