Past, Present and Future

[kandrathe]

For example, if you tried to shoot your father before you were born, somehow the gun would fail to go off.

Yeah, I don't buy that one at all. If the bullet is sound, the firing pin is sound, the action is sound, the gun will go off, and you will kill your father. The question then is; As your father dies, would you disappear? I would say no, meaning that either 1) going back into the time stream is impossible, or 2) you go back to a different time stream (parallel universe). I'm pretty strong on 1) being probably the right answer.

The experiment he's devised to test for backward causality plays off the idea that the states of two photons can become "entangled": Even if the photons are separated by great distances, what happens to one photon is reflected by the other one.

I don't understand how quantum entanglement can be used to test for the ability to reverse time. As I understand it, yes, entangled particles (I doubt they have to be photons) do synchronize across space-time even if they are in two different reference frames. This might allow for some oddities in quantum communication between reference frames, but I wouldn't call it time travel. It would be like saying that standing on a chair makes you taller. It does, but not in the sense that you might be a better basketball player.

Bruckheimer and Scott sat down with Dr. Greene

I recently dusted off an old Playstation game I had, "Parasite Eve", where the misunderstanding of mitochondrial DNA results in an interesting take on "monster" and playable video game, but hardly advances an understanding of biology. Actually, for kids, it probably confuses their understanding of biology. "OMG! Get this mitochondrial DNA out of me before I mutate into a three headed dog!"

On EPR communication, the key statement I read there was; "For this reason, a crucial test of quantum phenomena would be to re-create the Dopfer Experiment and observe the role of the coincidence requirement on what is observed in the lower arm detector. Several research groups are considering doing this, but there are no results yet." Whereas, a single experiment does not make proof, but begs to be recreated and the observable phenomena verified. Then, the author goes on to try to explain the implications, but fails to recognize that the two particles are now separated into different reference frames. In reverse, its like when we see a super nova millions of years after it happened. Not so useful. In the case of quantum communication, we can detect the flash of the super nova as it is happening (or soon after, but still FTL). Still not that useful, unless you want to send communications FTL, which is a theoretical possibility made possible by quantum entanglement. But... It's not time travel. It still happens in the "now" of both particles simultaneously.