Time Travel Possible?

[QuarantinedII]

Time Travel Possible?

Introduction:
I have recently been looking into the possibilities of time travel, and I have found this article in the Los Angeles Times that may help with your understanding of time travel.

The Quote:

From the outside, an Einstein-Rosen bridge, as wormholes were originally known, looks a lot like its cousin, the black hole. Which you must keep in mind that "nothing can escape from a black hole — not even light."

Einstein and Rosen made a very bold supposition: What if a traveler fell into the mouth of something that looked like a black hole, but rather than being crushed by a singularity at the center of a black hole, instead emerged from another mouth, potentially many light years from where he or she started? This isn't as crazy as it sounds. Einstein's theory of general relativity — our current working model for how gravity and space work — has been confirmed with countless experiments. And, as ad hoc as it sounds, an Einstein-Rosen bridge is a perfectly valid solution to the equations of general relativity.

And it's not just a shortcut through space. In 1988, Caltech physicist Kip Thorne also showed something else: If you can build a wormhole, you can also turn it into a time machine. By dragging one of the mouths of the wormhole around space at nearly the speed of light, we can create a two-way tunnel connecting two points in time. Even better, you don't need to worry about mucking up history. A time machine built from the laws of general relativity is necessarily self-consistent, and thus your history will remain safely as you left it.

However, Einstein's original concept had a few flaws. For one thing, going through an Einstein-Rosen bridge, later theorists have concluded, would have to be a one-way trip, since one mouth always serves as the entrance and the other the exit. An even bigger problem with the wormhole Einstein envisioned was found in 1962, when John Archibald Wheeler demonstrated that an Einstein-Rosen bridge would collapse before anything, even a beam of light, could travel through.

Fortunately, wormhole design has improved considerably in the last 75 years. In 1988, Thorne and his students took up the problem of traversable wormholes, in large part because of a plea from his friend Carl Sagan, who was then working on the novel "Contact." Thorne found that it was theoretically possible to construct models of wormholes, but they would require the existence of as-yet-undiscovered "exotic matter" — strange stuff that has less than zero mass — to keep them open. Unlike Einstein-Rosen bridges, Thorne's model was bi-directional and, more important, stable.

This all might seem like good news, but the fine print on wormholes is pretty daunting when you get into it. For one thing, we've never discovered anything like the exotic matter needed to prop wormholes open, and for another, we're not sure how we — or even a super-civilization — could punch a hole through the universe to create one in the first place. Furthermore, the idea of time travel is so anathema to many respectable physicists that some, including Stephen Hawking, have proposed a "chronology protection conjecture," basically insisting that physics must somehow outlaw time machines in order to keep "the universe safe for historians."
-Los Angeles Times

Conclusion:
In my opinion Time Travel is not possible, there is plenty of information out there on the internet that shows time travel could be possible, but I feel that it is not possible in this universe.
My question to you is "do you think that time travel is possible?"
-QuarantinedII

[SiN]

good stuff.. just wish i had one... would go back and slap my self few times.... ask WHY! you do that!

[John Henry Eden]

I think it's possible but I don't think we'll ever be able to go through a black hole without dying.

[QuarantinedII]

good stuff.. just wish i had one... would go back and slap my self few times.... ask WHY! you do that!

Why? I asked...
Also I am pretty sure in the future, maybe not my future, there will be a way to travel through time.
Riddle me this:
You're in a car travelling at 100mph
On the front of your car is a gun pointing forwards..
On the back of your car is a gun pointing backwards..
The guns both shoot their bullets out at 100mph when fired.

Ok..so you're travelling at 100mph, so are the guns attached to your car..
you fire both guns *bang*, one in front, one behind, both bullets are forced out at 100mph.. simple enough?

1(a)
How fast would you measure the bullet in front to be travelling away from you?
(b)
How fast would you measure the bullet behind to now be travelling away from you?

An idle bystander is also taking measurements of the bullets speeds from the sideline..
2(a)
At what speed does he measure the bullet which was shot forwards to be travelling through the air?
(b)
& at what speed does he measure the bullet which was shot behind you to be travelling through the air?

[CloudStrife7x]

i can actually time travel but i can't divulge the secrets yet guys sorry maybe later

[lickerout]

Why? I asked...
Also I am pretty sure in the future, maybe not my future, there will be a way to travel through time.
Riddle me this:
You're in a car travelling at 100mph
On the front of your car is a gun pointing forwards..
On the back of your car is a gun pointing backwards..
The guns both shoot their bullets out at 100mph when fired.

Ok..so you're travelling at 100mph, so are the guns attached to your car..
you fire both guns *bang*, one in front, one behind, both bullets are forced out at 100mph.. simple enough?

1(a)
How fast would you measure the bullet in front to be travelling away from you?
(b)
How fast would you measure the bullet behind to now be travelling away from you?

An idle bystander is also taking measurements of the bullets speeds from the sideline..
2(a)
At what speed does he measure the bullet which was shot forwards to be travelling through the air?
(b)
& at what speed does he measure the bullet which was shot behind you to be travelling through the air?

The quick answer is that relative to you, the bullet will always travel at the same speed. In other reference frames, however, unexpected things can happen!

Newton's first law:
"Every body persists in its state of rest or of uniform motion in a straight line unless it is compelled to change that state by forces impressed on it."

or rephrased a little:
a body in motion tends to stay in motion and a body at rest tends to stay at rest unless acted on by an external force.

So what does this mean for a gun? If the gun is facing forward and shoots bullets at 1,000 mph, then the bullet will always move away from the gun at 1,000 mph, so the speed of the bullet plus the speed of the car equals the speed relitive to the ground.

If you shoot the bullet off the back of the car, the bullet will still be moving away from you and the gun at 1,000 mph, but now the speed of the car will subtract from the speed of the bullet. And relative to the ground the bullet will now be moving slower than when facing forward.

but why ask a physics question about time travel, quantum physics is on another level all together.

[QuarantinedII]

Now lets set the exact same conditions, conduct the same experiment but instead of the car going 100mph we'll have it go at the speed of light.. & instead of bullets/baseballs being launched at 100mph we'll shoot light photons from lasers attached to the car, front & back, being shot out of course at the speed of light.
We'll call this experiment 2

The previous (theoretical) experiment showed that each observer (driver & bystander) measured the bullets/balls travelling at different rates than what the other observer did.. that's what they observed & is how they recorded it. Which is true. Both results were accurate relative to each observer.

The bystander observed the forward projected bullet/baseball travelling at 2x the speed of what it was actually projected/launched away at.
They also observed the rear projection apparently projected with no velocity at all.

So..
Is this then to say that if we conducted experiment 2 we would have the light photons being projected from the front laser travelling at 2x the speed of light, & the photons being projected from the rear laser travelling at 0, idle, according to the bystander?

[Emerald Lance]

Now lets set the exact same conditions, conduct the same experiment but instead of the car going 100mph we'll have it go at the speed of light.. & instead of bullets/baseballs being launched at 100mph we'll shoot light photons from lasers attached to the car, front & back, being shot out of course at the speed of light.
We'll call this experiment 2

The previous (theoretical) experiment showed that each observer (driver & bystander) measured the bullets/balls travelling at different rates than what the other observer did.. that's what they observed & is how they recorded it. Which is true. Both results were accurate relative to each observer.

The bystander observed the forward projected bullet/baseball travelling at 2x the speed of what it was actually projected/launched away at.
They also observed the rear projection apparently projected with no velocity at all.

So..
Is this then to say that if we conducted experiment 2 we would have the light photons being projected from the front laser travelling at 2x the speed of light, & the photons being projected from the rear laser travelling at 0, idle, according to the bystander?

Yes, for the instant of a photon's existence. The problem here is that we're dealing with theoretical physics. Einstein's theory of relativity is just that: a theory. Even though it has been a reliable measure of universal physics thus far, there is no possible way we could understand the entirety of the cosmos in such detail that we'd ever be able to prove (or disprove) said theory to be a law.

The same is true of wormholes in general. This all works around the theoretical concept of spacetime, which is (1) a theory and (2) something we barely understand as it is. Put in layman's terms, in general, spacetime is the simple mathematic practice of placing time and space within the same continuum. This works when explaining the flow of time along stronger sources of gravity; the stronger the gravity, the slower time moves (hence why time moves slower the closer one gets to the center of a black hole).

Let's call this "lighter than zero" matter "-1 matter" for this example. Assuming spacetime works the way we think it does, and assuming the theory of relativity is exact (and we simply have yet to prove it as a law of physics), backwards time-travel would still be impossible. Greater gravity produces slower time, and higher mass produces greater gravity; as we get lighter and lighter, time moves quicker and quicker. If -1 matter did exist, it wouldn't cause time to reverse, but would instead cause time to speed up, and -2 matter would cause it to go even faster. In other words, you're on the right track, but you're going the wrong way; in terms of the relationship between mass and time, the only way to move -BACKWARDS- in time is with the use of matter that is more dense than infinity!

Of course, the closer and closer we get to infinity (which by definition cannot be reached), the more and more intense the gravity well becomes. And the single moment in time that a particle is created with infinite density, time itself will stop completely as gravity instantly (not at the speed of light but instantly) crushes everything in existence down to a zero singularity (a singularity that has a size of zero). The only thing that will survive is the infinity particle, and only because it is, by its very nature, infinite and cannot be crushed down to nothingness. And then time will forever be at a standstill (there will be no big bang).

In short, my opinion on time travel is thus: I know it's theoretically possible to move forward in time at a faster pace than normal, but there is no way we could possibly move backwards in time without annihilating the entire scope of existence (at least in terms of gravity manipulation through mass density).