"Time Travel"

[SnWRifleman]

Have you ever heard of this theory? And it's not a world creation theory either. It's about mirrors and light and images bouncing off the Earth. Let's start off with the basics.

 

 

 

Our eyes are receptors that see the light bouncing off objects, which allows us to see things.

 

 

 

The sun shooting light at the Earth is what allows us to see. And therefore the light bouncing off the Earth is out there in space. I know it's confusing, but the light is bouncing off the Earth is traveling in light years is out in space and therefore, when it reaches other planets that might have some sort of foreign life, they can see the images.

 

 

 

For example, when you see a star, that particular star could have exploded like years and years ago. The light you see is still shining towards the Earth, showing you the image of the star, even though it was long gone.

 

 

 

Note: I do doubt that this can happen, but there is always that possibility. Plus it's just a theory they won't be able to prove for maybe hundreds of years.

 

 

 

Conclusion-

 

 

 

Scientists say that if they can build a powerful enough telescope that can travel faster than light years, they can basically "catch" up to the light that reflected off the Earth hundreds of years ago, and basically travel into time, seeing all the events that happened years and years ago.

 

 

 

 

 

Credits- My American History teacher for telling me this.

[Intriguing]

...that can travel faster than light years...

 

There's your problem right there, assuming you mean "faster than the speed of light". According to Einsteins Theory of Special Relativity, as well as experimental evidence, matter can not travel faster than the speed of light, 3 x 10^8 ms^-1.

 

I can see the logic behind the theory, but it's not exactly achievable in reality.

[assassin_696]

Scientists say that if they can build a powerful enough telescope that can travel faster than light years, they can basically "catch" up to the light that reflected off the Earth hundreds of years ago, and basically travel into time, seeing all the events that happened years and years ago.

 

 

 

What? Are you suggesting a moving telescope that travels faster than light? I think Herr Einstein would have something to say about that.

[Mercifull]

I dunno what John Titor would think about that...

[BlueLancer]

Scientists say that if they can build a powerful enough telescope that can travel faster than light years, they can basically "catch" up to the light that reflected off the Earth hundreds of years ago, and basically travel into time, seeing all the events that happened years and years ago.

 

 

 

What? Are you suggesting a moving telescope that travels faster than light? I think Herr Einstein would have something to say about that.

 

 

 

 

 

 

The world is still quite uneducated about some physics related subjects.. The media isn't helping by spreading wrong info :lol: What was the editor thinking

[assassin_696]

I'm still curious as to how something can be made to travel faster than a measurement of distance. :P

[thrash-boy]

I'm still curious as to how something can be made to travel faster than a measurement of distance. :P

 

 

 

he means faster than the speed of light.

 

 

 

as good as it could be, it cant happen according to Einstein

[warri0r45]

One problem. You can't travel faster than light.

 

 

 

Though it would be pretty fascinating to actually do that.

[eggzs]

How do you build a telescope that can "travel faster than light years"?

 

 

 

I'm pretty sure you mean the speed of light, but it is impossible for an object with mass to travel at the speed of light as the object will have infinite mass which is impossible (theres a formula for this, but I can't remember the correct one).

[MicroLegionnaire]

Scientists say that if they can build a powerful enough telescope that can travel faster than light years, they can basically "catch" up to the light that reflected off the Earth hundreds of years ago, and basically travel into time, seeing all the events that happened years and years ago.

 

 

 

What? Are you suggesting a moving telescope that travels faster than light? I think Herr Einstein would have something to say about that.

 

 

 

Theories and rules are changed every day, you never know, maybe one day Einstein will be proved wrong.

 

 

 

John Nash came up with a theorem on the forces of the market that contradicted more than a century of "proven" theories. And he turned out to be right.

 

 

 

Although the wording of the original post is kind of strange, and might have been warped after numerous re-tellings.

[Intriguing]

Theories and rules are changed every day, you never know, maybe one day Einstein will be proved wrong.

 

Certainly. However, all (or at least most) evidential evidence backs up the idea that nothing with mass can travels faster than the speed of light.** Until evidence is presented showing matter actually traveling faster than the speed of light, the OP's "theory" has no relevance.

 

 

 

**For example, electrons being energized to the extent that theoretically they should be travelling faster than the speed of light, c, but their velocity never goes above 0.9999... c.

[cadburys_egg]

Isnt it theoretically possible to travel in time, though? Assuming you had a rocket or some other space-transportation vehicle that could travel at nearly the speed of light. I remember being told this at a physics presentation once (by a Dr Loopey - no less), so I may regurgitate it wrongly.

 

If you were to travel nearly at the speed of light directly away from Earth, keeping a straight line, you would be getting younger since our time is relative to Earth. However, the moment you return along your path back to Earth, you would simultaneously be getting older. So if you did both of these things and landed back on Earth, you would actually be younger and older than you were when you had taken off.

 

Of course, if you want to just go further into time, invest in some cryogenics. Futurama style, yo.

[SnWRifleman]

I didn't make the theory o.o.

 

 

 

My AH teacher just told me about it. And I meant the speed of light :P. And nothing is impossible.

[Intriguing]

To cadburys_egg:

 

Sort of, it's called time dilation. Say a spaceship were built that could travel at 0.99c. An astronaut travels to a location one light year away from earth at a constant velocity, and when he reaches the location, he immediately turns back to Earth, traveling at a constant velocity.

 

When he returns back to Earth, he has traveled two light years (1.8922 x 10^16 m). If he is traveling at 0.99c (2.97 x 10^8 m/s) the entire time, ignoring the time it takes to turn around, it should take him approximately 737 days (6.37 x 10^7 seconds).

 

We can use the time dilation equation to see how much time he has taken from the perspective of a stationary observer, e.g. people on the Earth.

 

 

 

t = t' / root(1 - v^2 / c^2)**

 

 

 

Where:

 

t - Time taken from the perspective of the people on the Earth.

 

t' - Time taken from the perspective of the astronaut.

 

v - Velocity of the spaceship.

 

c - The speed of light.

 

 

 

t = [6.37 x 10^7 seconds] / root(1 - [2.97 x 10^8 m/s]^2 / [3.0 x 10^8 m/s]^2)**

 

 

 

t = 4.5 x 10^8 seconds = 5,226 days

 

 

 

So from the perspective of the people on Earth, fourteen years have passed, and yet he has only aged two years.

 

 

 

I apologize if I used the formula incorrectly. If I have, I'm more than happy to be corrected.

 

 

 

**I don't know how to indicate the "root of a number" symbol on the keyboard..

[dragoonson]

Just a question.If something is going the speed of light,you don't see it,right?Then how would you know if its going faster?

[assassin_696]

@cadbury's

 

 

 

Yeah, pretty much. Intriguing probably explained it better than I can but basically the faster you go the slower your time in your frame of reference goes. So if you take two twins, leave one on Earth and blast one off into space close to the speed of light, for say 10 minutes measured by her clock, then when she returned back to Earth she'd find that possibly hundreds of years will have passed on Earth. So one way time travel is very much possible, there's just no going back.

 

 

 

Scientists say that if they can build a powerful enough telescope that can travel faster than light years, they can basically "catch" up to the light that reflected off the Earth hundreds of years ago, and basically travel into time, seeing all the events that happened years and years ago.

 

 

 

What? Are you suggesting a moving telescope that travels faster than light? I think Herr Einstein would have something to say about that.

 

 

 

Theories and rules are changed every day, you never know, maybe one day Einstein will be proved wrong.

 

 

 

John Nash came up with a theorem on the forces of the market that contradicted more than a century of "proven" theories. And he turned out to be right.

 

 

 

Although the wording of the original post is kind of strange, and might have been warped after numerous re-tellings.

 

 

 

It doesn't quite work like that though. The constancy of the speed of light (and hence permanent speed limit) is a pillar for pretty much all the physics that's gone on in the last hundred years or so. If a theory was found that said you could go faster than light then nearly everything in physics would fall. I agree that science is never finished, modifications are always made, but even scientists are unusually certain that the speed of light is just the maximum. Of course, there are theoretical loopholes (dragging spacetime with you etc.) but i'd bet a lot of money on special relativity holding true.

 

 

 

Just a question.If something is going the speed of light,you don't see it,right?Then how would you know if its going faster?

 

 

 

Why don't you see it?

[cadburys_egg]

time dilation.

 

Yeah, pretty much.

 

Ah, right, thats what I was thinking of.

 

 

 

Just a question.If something is going the speed of light,you don't see it,right?Then how would you know if its going faster?

 

So we dont actually see light? Myth busted.

[Will H]

But what about worm-holes? I've heard that you can 'skip' distances by folding space, and then you could view the light that got through the long way round, taking hundreds of years to do so. Then you could view the Earth with your insanely powerful telescope and see it as it was hundreds of years ago.

 

 

 

Why do people think that the 'light barrier' has to be broken?

[warri0r45]

But what about worm-holes? I've heard that you can 'skip' distances by folding space, and then you could view the light that got through the long way round, taking hundreds of years to do so. Then you could view the Earth with your insanely powerful telescope and see it as it was hundreds of years ago.

 

 

 

Why do people think that the 'light barrier' has to be broken?

 

 

 

I was actually thinking about that when reading the original post. You have to keep in mind that wormholes, although theoretically possible by general relativity, haven't been observed yet. They're completely hypothetical.

 

 

 

But if they do turn out to be an empirical reality, then i suppose you could bend space-time and quickly traverse a distance that would normally take years for light to travel.

 

 

 

Anyone who knows more than about this than me? I know very little when it comes to this stuff, so feel free to add anything I missed.

[Intriguing]

But what about worm-holes? I've heard that you can 'skip' distances by folding space, and then you could view the light that got through the long way round, taking hundreds of years to do so. Then you could view the Earth with your insanely powerful telescope and see it as it was hundreds of years ago.

 

 

 

Why do people think that the 'light barrier' has to be broken?

 

Theoretically it is possible to use wormholes for time travel and what not. However, as of yet no wormholes have been observed, and I am under the impression that there are some additional problems that would ensue even if one were to stumble upon a wormhole. The point is that until we are actually able to observe wormholes, they have no practical application.

[demonfirzen]

This got me thinking, if we DID manage to get an object up to 0.99c, and if it had a light on it, and we pointed that light forward, what would happen?

[cadburys_egg]

This got me thinking, if we DID manage to get an object up to 0.99c, and if it had a light on it, and we pointed that light forward, what would happen?

 

The light would just stretch within that final 0.01c before the object it was on occupied it. It would just be like headlights on a car, except the light doesnt extend very far.

[Intriguing]

This got me thinking, if we DID manage to get an object up to 0.99c, and if it had a light on it, and we pointed that light forward, what would happen?

 

Imagine that there is a spaceship traveling at a constant velocity of 0.9999...c through a vacuum, and stationary observer watching the spaceship. At the tip of this spaceship is an astronaut holding a torch. When the astronaut turns on the torch, what happens to the light given off?

 

What happens to the light differs depending on which observer you are--let's start with the stationary observer. Given that the spaceship is practically traveling at the speed of light, and that light cannot exceed 3 x 10^8 m/s, the stationary observer sees the light given off from the torch traveling at the same speed as the spaceship. However, what the astronaut observes is different. The astronaut observes the light from the torch moving out from the spaceship at 1c, relative to the velocity of the spaceship.

 

One would think that this would mean that from the perspective of the astronaut, the light coming off from the torch is traveling at 1.9999...c, but it's not. For this to make sense, I'll use another analogy.

 

Imagine you are in a car traveling on a perfectly smooth road, with the windows covered up to the extent that no light is being let in, and you have earplugs on so that you can not hear sound coming from outside the car. In other words, your senses are completely limited to what is happening in the car. The car is traveling at a constant velocity. In other words, the car is not accelerating in any direction. If you were in this car, you would not know if you were traveling 5 m/s, 5000 m/s, or if you were not even moving. If you are traveling at a constant velocity, you need to have outside reference points (things moving at a different velocity to you) to know how fast you're going. This is the basis of Einstein's Theory of Special Relativity.

 

The spaceship, and therefore the astronaut, are traveling at a constant velocity, and so is the source of the light (the torch). From the perspective of the astronaut, who in relation to the stationary observer is traveling at 0.999...c, the light is traveling at 1c.

 

Our logic would tell us that this is incorrect as a ray of light can not be traveling at two different velocities at the same time. According to Einstein's Theory of Special Relativity, the astronaut flashing the torch from his frame of reference, and the astronaut flashing to torch from the stationary observer's frame of reference are not the same events--they are simultaneous events. The basis of Einstein's Theory of Special Relativity is that things are relative, in that they are not absolute, but dependent on the observer.

 

I apologize if I didn't so a good job of explaining it. It's sort of tricky to get your mind around, but it makes sense once you get it.

[assassin_696]

But what about worm-holes? I've heard that you can 'skip' distances by folding space, and then you could view the light that got through the long way round, taking hundreds of years to do so. Then you could view the Earth with your insanely powerful telescope and see it as it was hundreds of years ago.

 

 

 

Why do people think that the 'light barrier' has to be broken?

 

Theoretically it is possible to use wormholes for time travel and what not. However, as of yet no wormholes have been observed, and I am under the impression that there are some additional problems that would ensue even if one were to stumble upon a wormhole. The point is that until we are actually able to observe wormholes, they have no practical application.

 

 

 

Yeah, wormholes are one of those things that the mathematics of general relativity doesn't forbid, and you can get them out of the equations if you fiddle around enough. The problem for using them practically is that to maintain them you need some kind of "exotic matter", the composition of which is unknown to us but it has to have certain unique properties. Again, the exotic matter isn't forbidden, we just can't make it. Otherwise the wormhole would collapse in on itself as soon as you tried to use it. At least that's how I understand it.

[sonerohi]

Wasnt there a thread that had some type of groundbreaking time discovery a month or two before the rollback? I vaguely remember something about special cells or electrons, string theory, the two poles, and a laser of electricity that reached the destination before it was fired. Oh, and also one about how technically, time could be slowed with a new contraption that slowed down light emitted from a bulb.