Relativity of time?

Question

The faster an object moves, the slower time goes. If you're moving at c (lightspeed), time stops?

Speed is not absolute, but measured from a frame of reference.

If we measure our speed from the p.o.v. of an approaching photon, we are travelling at c (lightspeed). Are we not?

As time has not stopped for us that can't be the case. Our speed (velocity) is less than c.

What frame of reference are we in then, when seconds tick bye at the normal rate, and we live for around 60 years?

Answer 1

> The faster an object moves, the slower time goes.

True.

> If you're moving at c (lightspeed), time stops?

True. But only things without mass (like photons) can travel at that speed. No time elapses from the point of view of a photon.

> If we measure our speed from the p.o.v. of an approaching photon, we are travelling at c (lightspeed). Are we not?

That's a tricky question. The fact is, no measurement can be made from the p.o.v. of a photon (since no time passes). In particular, no measurement can be made of the speed of an "approaching" object. So it is, in some sense, meaningless to ask whether the human approaches at speed c relative to the photon. The rules change when you're traveling at exactly c.

> What frame of reference are we in then, when seconds tick bye at the normal rate, and we live for around 60 years?

Excellent question. The short answer is: Time always passes at its "normal" rate according to your own subjective reference frame.

Here's a specific case study that may make the point. Let's say two spaceships are separating from each other at a relative speed of 1/2 c. Spaceship "A" perceives his own clock to be ticking normally, but perceives (through whatever measurement you wish to make) that the clock on Ship "B" is running 13% too slowly. On the other hand, Spaceship "B" perceives that the clock on Ship "A" is running 13% too slowly.

It sounds like a contradiction, but it's not. The ships can do the following experiment to "prove" that the "other" ship's clock is slow:

Say that, at the instant they separate, the two ships synchronize their clocks to read "12:00". By a prior agreement, Ship "A" will send a signal (at lightspeed) to Ship "B" at exactly 1:00 (according to clock "A"). When "B" receives the signal, he will write down the current time (by clock "B") in the ship's log.

It turns out that the time in the log will be: 1:44. But each captain has a different explanation for that.

Captain "A" says:
"Clock B was running only 87% as fast as mine. At 1:00, when I fired the signal, that slow Clock B had only reached 12:52. At that instant, the separation between our ships was (1/2 c) x (60 min) = 30 light-minutes. Since Ship B was receding at 1/2 c, it took a full hour for the signal to overtake it. By that time, it was 2:00 by my clock, but only 1:44 by Clock B."

But listen to Captain "B"'s story:
"Clock A was running only 87% as fast as mine. At 1:00 (by my clock), It was then only 12:52 by that slow Clock A. Finally, at 1:09, slow clock A had reached 1:00, and Captain "A" finally fired his signal. By that time, the distance between our ships was about (1/2 c) x (69 min) = 35 light-minutes. So it took 35 minutes for the signal to reach my ship, and by that time it was 1:44."

So, there's the weirdness. There is no contradiction (each captain agrees that "1:44" is the correct log entry), but each explanation makes sense only if the OTHER clock is slow.

The lesson is, there is no absolute "rate of time" against which all other clocks can be measured. It's all relative.

Answer 2

You are playing fast & loose with frames of reference.
No wonder you're confused.

"The faster an object moves, the slower time goes. If you're moving at c (lightspeed), time stops?"
* First, an object can't REACH the speed of light.
As an object approaches the speed of light, its time rate approches zero BOTH OBSERVED FROM A FRAME OF REFERENCE AT "REST", NOT THE FRAME OF THE OBJECT.

"Speed is not absolute, but measured from a frame of reference."
* If you understood this, why are you making these mistakes?

"If we measure our speed from the p.o.v. of an approaching photon, we are travelling at c (lightspeed). Are we not?
As time has not stopped for us that can't be the case. Our speed (velocity) is less than c."
* You can't measure speed, (D/T), from a reference where T=0 can you? In any case what effect would that measurement have on us? (NONE!)

'What frame of reference are we in then,..."
* Whatever frame we ARE in, no matter it's relation to any other.

Get it now?

Answer 3

You will live for 60 years in your own frame of reference. Someone else moving at near the speed of light will observe you aging more slowly while you in your frame will observe him aging more slowly. This is known as the twin paradox. One of the many strange things about relativity.

Answer 4

Time is linear, a single direction - present to past. The physics trilogy describes the basis of our reality, and it gives a clue as to why things operate as they do. The trilogy is: E = mc2, m = E/c2, and c2 = E/m. The last is that of a field of gravity, which is a field of physical time. This equation describes the "c^2" concept as being an energy/mass relationship, while the first two describe the basis of our existence itself is this very same value of "c2".

In the first equation the value of "c2" is the multiplier and in the second the divider. In each of these it is the basis of the equation itself. What this means is that all forms of energy and mass are composed of this value. Our universe and all within are composed of physical time "c2". It is for this reason the present moves into becoming the past at the rate it does, and this rate of change is the same throughout our universe. Every event moves from "present time" to that of the "past", which means our universe moves in a single direction.

Mass moving to the speed of light would change into electromagnetic energy. Mass would change from being a three dimensional entity into becoming that of physical time. This may be thought of as m = c^3, or a cube of time. A cube of time "c3"is that of 1 kg. or 2.2 lbs.

Were all the mass of our universe converted into electromagnetic energy (of which it is composed), then it would have changed from a three dimensional universe into that of a single dimension. At that instant physical time would have ceased to exist, for it requires the presence of a mass to form the concept of time.

So, the frame of reference is our own selves. As a person approaches the speed of light, they become the clock by which time is gaged by.

Answer 5

Basically time relativity is related to how fast someone moves.It can be postulated as follows;
1- The faster one moves the less time it takes to reach the destination
2- The slower one moves the more time it takes to reach the same destination.

Answer 6

According to the theory of Relativity, if you are moving at a high speed relative to something else, time passes more slowly on the something else, not for you.

Answer 7

As you approach the speed of light, your mass also increases. At the speed of light your mass would be infinte, which is why it is assumed you can't actually reach the speed of light.

Answer 8

evaluate the time it takes to combine the climate and bake the cakes. The time varies with how many bran cakes you have the desire to make, besides because of the fact the scale of the cakes. That mentioned, bran cakes will advance in mass as they concepts-set gentle speed and contract particularly than advance. See my previous remark on the sci notation of the bran muffin. .