One summer 2011 evening, in the courtyard of our house, I got into the act of recording myself with my webcam, and I find that I am explaining the concept of, Time Travel — verbatim, with no prior writings.
Get yourself lost. Somewhere. So that I don’t see you.
I don’t care, I am supposed to drink this sprite or not.
But the fact is; I am wrong. Well that just that one sip that’s just reminded me, something, something aesthetic something exotic in the taste of the drink.
That’s right. I just drink a lot, so I would know.
It corresponds to the past. This is time travel.
Time travel can happen in your memory, cos in quantum mechanics, where it concerns very small objects concern very small object, time travel has some meaning.
Time travel doesn’t have a meaning in classical physics, you never see the arrow of time getting reversed for the classically sized and scaled, objects, these objects never go back in time, you never see that, you never see something reversing, it goes that way and it comes back exactly the same way, not even for a single object, so this whole thing, this whole jamboree o’ objects, they can never all, at the same time, go back in the arrow of time, to produce what is called a reversal in time, reversal in motion.
You never see that in classical world. But in the quantum mechanical world, this has certain meaning. Certain meanings.
What is it?
The, quantum mechanical sized objects, particles, small particles, photons, electrons, protons, atoms, I am not even thinking of atoms, but very tiny particles, very small particles, when they are exchanging the information, their 4-vector information, their momenta, energy, this and that, what is happening there?
Particle comes and meets. You think they are meeting like, in classical object, exchanging some information, then going back and forth, then just come back and meet again? Hey .. “time travel, we are meeting once again”.
I did that gesture, in a classical way, but not in a quantum mechanical way.
In a quantum mechanical way, this is not happening, this is just one component, and no component is complete, no path is complete, no amplitude is complete, its a mix of a very different kind, in a very different type of processes, very … well, multiple processes, multiple amplitudes, multiple things happening all at the same time, it does not make sense that there is one single electron and its exchanging information with that photon or proton … this and that …
It was starting the whole thing as a whole.
So as far as the experimental truth is concerned, it may be so, that only a part of the electron exists here and a part of electron exists here (hand gestures in opposing direction) this (electron part 1) is exchanging information with whatever is coming here (onto region 1) this (electron part 2) is not.
It may mix and jumble and wiggle, like go back and forth, in all sorts of ways possible, and when they meet back together, some of the information, that they saw in the past, might still be conserved, in that process and you see that thing, so for the particle world, there is time travel, that is, a reversibility is possible, in a very small, minuscule, minute ways, but its not possible in a classical large scale object way, nothing goes back exactly the same way it comes ahead.