Why do you age slower the more you approach moving at the speed of light?

Question

The theory of relativity says that if you were able to move away from the earth at close to the speed of light that when you return much more time would have passed on earth than you would have experienced. Why? It seems like if you were moving that fast that others would be moving slower relative to you, not faster. Can anyone explain in layman's terms?

To be clear, I understand that you wouldn't be aging any slower by your own observation, just relative to Earth once you returned. So those who keep trying to explain that aspect, I understand, thank you. But please explain why when you return to Earth much more of "their" time will have passed.

Answer 1

The special theory of relativitiy is based on the fact that the speed of light is constant and independent of the frame of reference. This means that if you are traveling extremely fast in a spaceship and measure the speed of a light particle heading towards you, you will measure the same speed for that light as someone in a spaceship who is moving very fast away from the speed of light. To make a long story short.......once you accept that the speed of light is constant you can show that the distance the light travels is different, depending on the frame of reference that it is measured in. Since v=d/t and v is constant, a changing distance can only be accomplished by a changing time. Therefore, Einstein concluded and showed that time is relative to the frame of reference. The faster you travel, the less time you will observe.

Answer 2

Here goes - and without any mathematics:

According to relativity, space and time are interconnected. Time slows at great velocities - and distances also shorten in the direction of travel.
It is this phenomenon that results in the speed of light being exactly the same for all observers.
As far as "age slower" - this is strictly a reference or relative phenomenon. It will only be apparent if the traveler returns back to his original reference.
And here's the paradox - you will observe the time in another reference which is moving relative to you as going slower than yours - and they will reference yours as going slower!
Time will be perceived as passing at the "normal" rate in both systems - if the time dilation is 50% - each observer will complete an hour's worth of work in one hour - except, according to the earth bound observer, it will take the traveler two hours!
If the space traveler sends his earth bound buddy a message, the earth bound observer will have to tape it and run the tape back at twice the recorded speed to understand it.

It should present some very interesting paradoxes and experiments when this aspect of relativity moves from the precision instruments and the laboratories into the realm of actually experiencing this phenomenon!

Answer 3

The Lorenz Transform L(v) = 1/sqrt(1 - v^2/c^2) is the culprit. As v --> c, L(v) --> infinity. This transform can be found in several relativistic equations:

M = m L(v); where M is the relativistic mass based on how fast m, the rest mass, is traveling (v). Thus, rest mass on the vessel seems from outside to increase to M as v --> c. But an observer on the vessel would still see the mass as m. It's M, not m, that we see in E = Mc^2 = m L(v) c^2.

T = t L(v); where t is the passage of time inside a vessel traveling at v velocity and T is the passage of time outside the vessel. This is called time dilation because the time t seems to be stretched out (dilated) into a longer time T as seen from the outside.

For example, travel fast enough and one year's passage on board would be seen as 100, 1000, 10,000 or more years passage outside the vessel...depending on how fast v was. This is one feasible way to travel into the future.

This is also how you "age slower" than people outside the vessel. You would think your aging was normal, however, until you stepped out of your vessel back on Earth and found all your friends and family had grown old and passed on while you aged just one year.

L = l/L(v); where l is the apparent length inside the moving vessel in the direction of its velocity (v) and L is the length of it as seen from outside. Note the L(v) is in the denominator here, which means the vessel length L --> 0 as v -->c and seen from outside. Inside, the passenger would see no change and l would remain l as it was when v = 0.

The Lorenz Transform explains what happens when a vessel moves fast, but it truly does not explain why the increases and dilations occur. For example, to date, we really do not know why some energy has inertia, which we call mass, and why others, like photons, have no mass and, therefore, are not affected by the Lorenz Transform. Nor do we know why the Lorenz Transform affects time; we simply know that it does, but not why it does.

Classical and relativistic physics are good at explaining what happens, but not why they happen. String/M theory is trying to explain why things happen and their multidimensions are just one hint that what we see in our 4D universe is not all that there is to this universe. [See source.]

Answer 4

From a velocity standpoint, the effect is reciprocal, so while your clock looks slow to people on earth, their clocks appear to run slow to someone on the ship PROVIDED the ship is traveling at a constant velocity.

The real trick is you have to go thru periods of acceleration and deceleration in the spaceship to build up a relativistic velocity and then return to a stop, which the people on earth do not experience. That's why the clocks won't agree when you return. Clocks in an acceleration field run slower, as per general relativity.

Edit: Whoever gave this a tumbs down should come on board and challenge it up front. These twin paradox issues have long been resolved, and the answer is the changing reference frame the ship experiences which the earth does not.

Answer 5

When there is relative motion between two, say A and B,
A says B is moving and B says A is moving.

A will say in the moving frame of B, the length is decreased; time goes slow and mass increases.

B will say in the moving frame of A, the length is decreased; time goes slow and mass increases.

It is because they are in uniform motion relative to each other.

Now there is a doubt whether the B’s clock’s hand moves slowly in the frame of B or is it an appearance.

B will not feel any difference in the working of the clock.

It is A who says that the B’s clock’s hand goes slow compared to his clock and for him B is moving.

Similarly B will say that the A’s clock’s hand goes slow compared to his clock and for him A is moving.

Being relative in nature, which clock goes slow, can be tested only by making one of the clocks to return to its starting place.

When one is returned back, during the return path also both are in relative motion and direction is not a matter for the clocks to go slow.

Both A and B will say that the other man’s clock goes slow.

Now suppose A finds that B has returned his path.

B in order to change his direction of motion he has executed some circular trip or an accelerated motion.
During this time he is not having uniform relative motion and there is no slowing of time during this motion in the point of view of A.

A says that the clock of B slows down during the forward motion and also during the return trip.
When he reaches him he finds B’s clock has slowed down to the extent of time he has traveled.

Thus there is real slowing of time for objects moving with respect to one who is at rest.

In the above narrations, if A has returned his path to compare the clock, then B will say that A’s clock has slowed down.

Time is RELATIVE and it is not absolute to compare one’s time with that of other one’s time.

Where as, the speed of light is absolute for all .

Answer 6

Because in Einsteins theory if you were to exceed light speed you would in fact travel backwards through time, therefore you would age slower because you are in a sense slowing down time. This is of course as of now impossible, maybe in a few thousand years.

Answer 7

In layman's term, there is no such thing as time...space and time are actually together... i think you got it wrong ...people age slower when on earth because of gravity which bends light and makes it move slower therefore the time taken for the light to travel from one point to another is slower therefore earth is a slow planet and people age slower there while they age faster in space as there is no gravity and light does no slow things therefore light travels faster and things happen faster

Answer 8

You age at the same speed as far as you can tell. But others see you aging slower. It's all relative, which is how it got its name. Clocks, electrons orbits, chemical reactions all slow down as they approach the speed of light.

Answer 9

well alpha centauri is about 4.2 light years from earth, so we are seeing it as it was 4.2 years ago, now get into a ship and go to alpha centauri. at the speed of light, it will appear that alpha centauri is now going twice as fast and it would appear that the earth has stopped (from your perspective) because your riding on the visual light rays that came from earth, once you get to alpha centauri and stop, both alpha centauri and earth will be moving again at normal speed and time, you will be seeing earth as it was 4.2 years ago. keep in mind that the earth is still aging normally from the perspective of the people there. now when you head back at the speed of light, alpha centauri stops (your perspective) earth ages 2x now, because your catching up the the visual light rays 2x as fast. when you get to earth and stop, everything is equal, you age the same as the person on earth. maybe alittle different because of the lack of gravity and sun rays hitting you of course.

Answer 10

I'm not sure if the fundamental nature of why time slows down is understood, any more than the fundamental nature of what matter is.