a space/time question

[andytheplumb]

If it is true that there is a relationship between space and time, and that from what i understand, the faster that you move the slower time passes, i have a question that puzzles me!! The equator of the earth makes a complete rotation every 24 hrs, meaning it has travelled the circumfrance of the earth, 24,000 miles'ish at a certain speed probably around 1000 Mph. Now if the land that was a few miles from either of the poles would only have rotated say a few miles at a much slower speed. Does this make the equator of the earth younger than the poles? ? ? ?

[fo3nix]

You want to look into what's called Special Relativity. There are many, many books on this (it's an Einstein thing, so is always popular). It's really not that hard to understand either.

And in answer to your question: time dilation as it's called only starts being noticed when you get close to the speed of light, which is about 300,000,000 metres/second. So even 1000mph is pretty slow compared, so maybe it'll work out to be a difference of a second or after every several thousand years. Nothing much really at those speeds.

[adonia]

time can't be measured unless it's by a human relationship.. IMHO, I'd refer to velocity to grasp an imagination of what "time" is...if you know what I mean, it's like trying to measure space...when did it start and where does it go? speed would be finite..

[woodchopper]

There are sometimes when I think its a load of old cobblers - then again its probably because I do not totally understand the physics behind it - you mean to tell if I were to travel at let's say 1,000,000 mph ( if it were possible ) my wrist watch would slow down ??
Please explain ( so that even the offspring of a TV weathergirl and the local vilage idiot could understand ).

[mibn2cweus]

When we consider General Relativity (the effect of gravity on the passage of time) together with Special Relativity (the effect of velocity on the passage of time) I believe we might find that a clock on the Equator runs at the same speed as a clock on the North/South Pole. The Earth takes the shape of an oblate spheroid due to its rotation and so gravity is stronger at the Poles.

I have not considered this before but I find it intriguing, meaning that this post is more of a question that an answer.

[bernardo]

The short answer is yes.

There is a Russian cosmonaut who has has spent so long in space (more than a year in total) in orbit around the Earth at such high speeds that he has aged by a fiftieth of a second less than he would have done if he had stayed on Earth. Or, to put it another way, he has travelled a fiftieth of a second into the future. The equator is going much slower, but the principle is the same.

[dawkins]

hummm. sort of. The earth beneath our feet is not static, every thing below us moves around, the seas move around and the stuff deep down in the earth moves around. This movement would tend to counter any localised time dilation, but in theory I think you are correct.

D

[dawkins]

ON THE ELECTRODYNAMICS
OF MOVING BODIES
By A. Einstein
June 30, 1905


"we conclude that a balance-clock7 at the equator must go more slowly, by a very small amount, than a precisely similar clock situated at one of the poles under otherwise identical conditions."

[mibn2cweus]

The effects on the passage of time due to variations in gravity & velocity cancel so there is no point in moving to the equator at this time!

[rojash]

Surely Bernado, if he has aged a fiftieth of a second less, then he has been left in the past, rather than travelling into the future?

[bernardo]

No, the time from his point of view has been a fiftieth of a second less than the rest of us, so his time has been streched. He has travelled a fiftieth of a second into the future, and has returned to a world in which everybody else is 0.02 seconds older than he "expected" them to be.

If his journey in space had been *much much* further and faster and longer, then he could (theoretically) have come back to find that all of the people of his age had aged by 30 years when he only aged 1 year. So he would have travelled 29 years into the fure without aging as much as the rest of us.