Do you believe that time travel is possible?

BigToque

Lifer
Oct 10, 1999
11,700
0
76
Why or why not?

One of the things that I don't understand about the theory of relativity is that when something approaches the speed of light, time slows down.

That really doesn't make sense to me. Time is time. 1 second is always 1 second. Whatever we define as an interval, will always be the same interval. The amount of distance you can cover might be greater or lesser depending on the velocity, but the inverval is the same.

Say I have some machine that can take me 100 light years in 1 second. When I reach my destination, I have aged 1 second. So have the people on earth. If I come back in 1 second, I'll have been gone for 2 seconds total, and both me and the people on earth have aged 2 seconds.

This is my take on it anyway.

If my logic is wrong, wouldn't that mean that people who travel more (on planes, cars, etc) will outlive other people simply because while they are moving, time is slowing down for them, while being constant for the people standing still?

It simply makes no sense to me.
 

her209

No Lifer
Oct 11, 2000
56,352
11
0
We are traveling through time right now so its definitely possible.
 

rh71

No Lifer
Aug 28, 2001
52,848
1,045
126
watching Back to the Future on TBS right now are ya ?
 

The most i believe is possible is to slow/speed up the aging process through space travel at higher speeds than we are obtaining now.
 

BigToque

Lifer
Oct 10, 1999
11,700
0
76
One of the things that I don't understand about the theory of relativity is that when something approaches the speed of light, time slows down.

That really doesn't make sense to me. Time is time. 1 second is always 1 second. Whatever we define as an interval, will always be the same interval. The amount of distance you can cover might be greater or lesser depending on the velocity, but the inverval is the same.

Say I have some machine that can take me 100 light years in 1 second. When I reach my destination, I have aged 1 second. So have the people on earth. If I come back in 1 second, I'll have been gone for 2 seconds total, and both me and the people on earth have aged 2 seconds.

This is my take on it anyway.

If my logic is wrong, wouldn't that mean that people who travel more (on planes, cars, etc) will outlive other people simply because while they are moving, time is slowing down for them, while being constant for the people standing still?

It simply makes no sense to me.
 

Cattlegod

Diamond Member
May 22, 2001
8,687
1
0
Originally posted by: Stefan
One of the things that I don't understand about the theory of relativity is that when something approaches the speed of light, time slows down.

That really doesn't make sense to me. Time is time. 1 second is always 1 second. Whatever we define as an interval, will always be the same interval. The amount of distance you can cover might be greater or lesser depending on the velocity, but the inverval is the same.

Say I have some machine that can take me 100 light years in 1 second. When I reach my destination, I have aged 1 second. So have the people on earth. If I come back in 1 second, I'll have been gone for 2 seconds total, and both me and the people on earth have aged 2 seconds.

This is my take on it anyway.

If my logic is wrong, wouldn't that mean that people who travel more (on planes, cars, etc) will outlive other people simply because while they are moving, time is slowing down for them, while being constant for the people standing still?

It simply makes no sense to me.


that isn't even the 1/2 of it :) your dimension also shrinks too in the direction of travel.
 

illusion88

Lifer
Oct 2, 2001
13,164
3
81
You have it all backwards. In fact you are dead wrong.

Space Time is relative. Time, as you put it, is a mixture of everyones space time. Time is not constant.
 

BigToque

Lifer
Oct 10, 1999
11,700
0
76
Originally posted by: illusion88
You have it all backwards. In fact you are dead wrong.

Space Time is relative. Time, as you put it, is a mixture of everyones space time. Time is not constant.

Care to elaborate? I don't understand what you mean.

You seem to be making a distinction between "Time" and "Space Time"
 

illusion88

Lifer
Oct 2, 2001
13,164
3
81
Originally posted by: Stefan
Originally posted by: illusion88
You have it all backwards. In fact you are dead wrong.

Space Time is relative. Time, as you put it, is a mixture of everyones space time. Time is not constant.

Care to elaborate? I don't understand what you mean.


The princibles of relativity: Whatever might be their nature, the laws of physics must treat all states of motion on equal footing.

This rejects the theory absolute space, which is what the OP had described. (Absolute space(time) was a theory of Newtons, stating that all objects will experience the same time, regardless of their motion.)

Imagine this. I am the proud owner of a fancy sports car, driving down Van Ness Ave in the middle of the night. You are a napping police officer. On top of my car I have a series of m80s. One on the front bumper, one over the rear bumper and many inbetween. I set them off to be detonated simultaneously, as seen by me, just as I pass the police station.

To me, the firecrackers appear to be at rest when I set them off. To the police officer, were he not napping, they are moving forward. If I were to graph this I would graph the tilt to right (time beign on the y and distance on the x).

I hope that explains it.

EDIT: better proof.

Imagine this. Put a flashbulb in your fancy sports car. When it goes off, it sends a beam of light to the front of the car and a beam of light to the back of the car. Since the two beams are emmited simultaneously, and the bulb is in the exact middle of the car, then the two beams reach the front of the car and the back of the car at the same time.

Now, examine the two beams as the car speeds past me on Van Ness. To me, the back of the car is moving forward, toward the beam of light, and thus will meet eachother sooner as seen by me then seen by you. Similarly the front of your car is moving forward, away from the light beam, and thus will meet eachother later as seen by me. (This only holds true if we both agree on a speed of light.)

Therefore, I regard the beam hitting the back of your car occuring before teh beam hits the front of your car.
 

Eureka

Diamond Member
Sep 6, 2005
3,822
1
81
I never really understood the point of relativity... it seems to me like perspective.

Anyway, yeah I remember seeing how time travel is possible, but only back to the point when the first time machine was invented. The time machines are rather gateways.

Norm
 

illusion88

Lifer
Oct 2, 2001
13,164
3
81
Originally posted by: cevilgenius
I never really understood the point of relativity... it seems to me like perspective.

In essence thats what it is. Each of us experience a different space time! In fact, although its not detectable, your feet experience a different space-time then your head does! Your feet are moving slower, and experiencing more gravity, then your head is. Your head is older then your feet.

Right now, your "second" could be longer or shorter then mine. although, the difference in time couldn't be measured by any conventional sense.
 

Cerpin Taxt

Lifer
Feb 23, 2005
11,938
520
126
Time doesn't exist. That is to say, we are not "in" time. There is no "time-stuff" in which we are immersed, as we would be immersed in water or somesuch. Rather, what we call time is a manifestation of our consciousnesses moving more-or-less uniformly together. It is a sort of psychological effect that emerges from our conscious orientation in reality. Our abilities to percieve probable futures and pasts creates the illusion of linearity, but basically there is no objective distinction between past, present and future. All events are simultaneous, therefore.

Given the above, "travelling back in time" doesn't really make much sense. The very idea of travelling "through" time is incoherent.
 

Rage187

Lifer
Dec 30, 2000
14,276
4
81
Science says it's possible.


We just lack the technology to affect gravity as much as we need to.

EDIT: AFAIK you can only move forward through it, through use of a large gravitational force.
 

techs

Lifer
Sep 26, 2000
28,561
4
0
Originally posted by: Stefan
Why or why not?

One of the things that I don't understand about the theory of relativity is that when something approaches the speed of light, time slows down.

That really doesn't make sense to me. Time is time. 1 second is always 1 second. Whatever we define as an interval, will always be the same interval. The amount of distance you can cover might be greater or lesser depending on the velocity, but the inverval is the same.

Say I have some machine that can take me 100 light years in 1 second. When I reach my destination, I have aged 1 second. So have the people on earth. If I come back in 1 second, I'll have been gone for 2 seconds total, and both me and the people on earth have aged 2 seconds.

This is my take on it anyway.

If my logic is wrong, wouldn't that mean that people who travel more (on planes, cars, etc) will outlive other people simply because while they are moving, time is slowing down for them, while being constant for the people standing still?

It simply makes no sense to me.

The first flaw is you can't travel 100 light years in 1 second. It takes 100 years at the speed of light to travel 100 light years.
Relativity says the speed of light is the maximum speed. In fact as you approach the speed of light and put more energy into going faster much of the energy goes into your mass and not increasing your speed. At the speed of light all the energy you put into going faster transforms into mass not greater speed.
If you travel say 10 years at close to the speed of light your time passed will be 10 years. According to relativity the people on earth (who are traveling thru the universe at a much slower speed) will have passed a lot longer, say hundreds or thousands of years.
At least thats what Einstein says and every test that has been done to test relativity has supported it.
 

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