Time machine being built!

[ThatGirl]

This video is shit.

 

[ygolo]

If my prophecies, whether about the sun or about sending back information through a time machine, were actually to "determine" the course of the future in advance (and I hesitate to even say that, because it's incoherent), it would be as though a spell had come over things and they no longer had any alternative but to obey me; I myself would fall under the spell, too, for I would have no choice but to follow the law set down by my earlier self. In short, I would become a kind of god, and not only that, but both the present and the past would vanish, neither of them having a place in which the future is already actualized as the sum total of existence, and everything would become a static image of the future that I foresaw. It would be very much like a dream, with that same sense of timelessness about it that can only exist by attaching itself, like a symbiote, to the waking flow of time.

I wondered, too, what would happen to free-will as soon as one of these machines was turned on (assuming it is possible). Would the messages traveling to the past force us to resend those messages when the time came? Or are messages being sent to alternate universes?

Anyways, the idea is at least three years old, and I have not heard of us making any progress towards making it a reality.

 

[Fluffywolf]

Reading this made me think about that knife in Pullman's trilogy that could be used to search for weaknesses in the air to open up windows to other worlds. Oh, how those books defined my childhood.

The time machine reminded me of this:

Yeah but this idea theoretically captures the particles as time rewinds, keeping them in the right place in space. This is why the time machine theoretically only works from the moment it is turned on.

 

[Eric B]

The premise's flaw is that simply going faster that the speed of light reverses time. It's not a speed, it's multiple changing of inertial frames of reference that cause the time reversal.
If you head to Alpha Centuari at 4c, it will still take a whole year to get there. It's if you head out at that speed, beam aboard a ship traveling the same direction at just under the speed of light, and then from that ship's frame of reference try to return to earth at 4c, that the trajectory would have you arrive here before you left.

And that might not work with the space rotating with you, and speeding you up. The frames of reference then are themselves accelerating (rotation is acceleration), so to go back over them would probably cancel out any such FTL effect.

That "missing the earth as you go back in time at the same spot" illustration shows the relativity of absolute location. Going back in time would seem to be simply reversing the state of all matter locally.

 

[Queen Kat]

Why would we want a time machine? To go back in time and kill Hitler? Dude, that guy is already dead, so you don't have to go back in time to take care of that!

 

[Litvyak]

Why would we want a time machine? To go back in time and kill Hitler? Dude, that guy is already dead, so you don't have to go back in time to take care of that!

Plus last time we did it had dire consequences!

 

[Polaris]

I wondered, too, what would happen to free-will as soon as one of these machines was turned on (assuming it is possible). Would the messages traveling to the past force us to resend those messages when the time came? Or are messages being sent to alternate universes?

Determinism can never cancel out free will, because free will is the foundation on which determinism rests: to know that things are causally linked up, to put them into any kind of rational system is to freely impose order on that same freedom, and not as its cancelation but as its very expression.

Freedom in its essence corresponds to "thought" in the structure thought-about-the-coincidence-of-thinking-and-truth, and is recognized not by retaining its form as a pure freedom but by collapsing itself into the form of the "thinking" in that structure. What this means is that the primary "thought" in that structure (the primary thought being the absolute freedom of becoming) is not an actual thing but a way of referring to the incompleteness of the actual; it is shorthand for saying that every thought of ours, every object of consciousness is, at the moment it exists, being surpassed toward something else through the spontaneity of freedom.

This spontaneity is not known in its purity; at the moment of its purity—at this and every moment when we are freely engaged in life—this spontaneity is known through the fact that the moment something is determined, the moment a truth arises, that truth is already past and a new one is being presented. In order to grasp this pure freedom, in order to get a hold of a present that hasn’t already been transcended, we would need to grasp not a particular thing presenting itself but nothing at all; for every time we try to refer to freedom in some way, we have not freedom but a particular concept that is being surpassed in more or less the same way as anything else. To grasp freedom in its purity, we would have to empty thought of its contents, for it is these that are doomed to fail at capturing it. In the end we would have nothing left at all, and this ineffable nothingness would be pure freedom.

That intuition is, of course, meaningless by definition, and yet this meaningless intuition leads consciousness on like a carrot dangled before its face; everything we see and do is known only as an act of going toward something that didn’t exist at the moment the act of going toward it was being performed, but which came to exist at exactly the moment that act was finished. An act of becoming is in a sense a creation ex nihilo; it launches itself toward something that isn't real, toward the nothingness of freedom, and at the moment its journey comes to a completion, both it and the nothing it was reaching for take on the mantel of reality.

Nature provides us with a particularly stark illustration of this principle at play; not only our thoughts and actions, but a dream especially is something vast and unreal that comes to reality not when we’re immersed in it, but at the moment we awaken; at that moment, something timeless and transcendent, a thing utterly mythological and chaotic, is given a rational form that nevertheless recalls its origins in the womb of chaos. All things in reality are like that—every instant is like waking up from a dream, brief or long by the measure of objective time and in itself eternal. This eternity, this absolute freedom of creation is lost but also discovered when it loses itself.

Can one imagine a world or even an instant in the world when freedom is quashed by determinism? No, because there would be nothing to be determined in the first place if it weren’t for freedom (and, of course, there is nothing to be determined, and we've already done so and will continue doing it forever, but only metaphorically speaking, not literally as determinism would have it).

 

[Arthur Schopenhauer]

I wonder how long it'll be till we have this:

I can't wait

No, this!

 

[spin-1/2-nuclei]

unfortunately it's just pseudoscience at the moment... There are many flaws with this person's "theories" on time travel, but I'll just list a few...

We don't have the requisite energy to alter spacetime in the way he is suggesting... he would need to create an "opening" many orders of magnitude larger than our universe because we have limited technology available today to reach that kind of energy level with our lasers.

Technically less energy would be required as the speed of light decreases (in a superfluid or something of that nature) - but this is not the same as the speed of light in a vacuum which remains constant - thus lowering the speed of light through a superfluid etc is not going to provide much help as simply decreasing the speed of light in a medium is not directly proportional to decreasing the speed of light in a vacuum.. we have yet to accomplish the later.

There are many other problems with his idea as well... but the main problem is that he does nothing to address the problem of where are we gonna get all that energy to even attempt to make something like this work...

It's a cool idea and makes great movies etc, but unfortunately remains pseudoscience at best and science fiction at worst today...

 

[Robopop]

The premise's flaw is that simply going faster that the speed of light reverses time. It's not a speed, it's multiple changing of inertial frames of reference that cause the time reversal.
If you head to Alpha Centuari at 4c, it will still take a whole year to get there. It's if you head out at that speed, beam aboard a ship traveling the same direction at just under the speed of light, and then from that ship's frame of reference try to return to earth at 4c, that the trajectory would have you arrive here before you left.

Wouldn't this be more like a kind of warp drive? Having space push you faster than the speed of light should not effect time(this happens with the universe as a whole, space is expanding faster than the speed of light). I thought you would have to travel through space for time dilation to take effect.

 

[Eric B]

That's what I meant. Even if space is expanding faster than light, at each local area of space, you are still bound by the limit of c, and would be separated from the area of space moving away faster than light by many other local areas where you would still be bound by c.