The future is now !1!!! :shock: More information: Scientific Reports (2019). http://dx.doi.org/10.1038/s41598-019-40765-6 sauce: https://phys.org/news/2019-03-physicists-reverse-quantum.html
^^ "sauce" ??? hmmm... So OS in such quantum computer can go back in time to prevent the error/failure. Cool!
Further reading with similar implications here: https://www.nature.com/articles/s41586-019-0952-6 What I find interesting is that the first quantum computers are already in use with certain universities (probably US mostly due to funding). The "partial" "reversal of time" is a very interesting, and dangerous implication, since it could in theory counter EVERY bit of encryption, find out EVERYTHING you want to know etc. but only in theory, since how we read from the articles, the more complicated, the more difficult it is to reverse the effects, and we're just talking about 8 qubits, and the universe has an unlimited amount of them to calculate, with 100% error correction needed to reverse engineer etc. etc. Cool stuff anyways. The better our quantum computers will get, the better they will be at helping us understand why things are like they are. And the easier we can run Crysis with high FPS and downsampling.
They found the algorithm which reverses the quantum state of quantum computer. Which is hard to compute and it's a highly improbable event, yes, true on both accounts, but I fail to see how it's got anything to do with common understanding of time reversal. Just because you can calculate conditions for bunch of rolling balls to end up in a still pyramid, does not equate to time reversal... jesus
You guys are all right, they did not reverse time itself. But they found an algorithm, an equation, that remains true even if it works against the second law of thermodynamics, which in it's implications does say time is not irreversible, and any such equation has to return false after time has passed. So theoretically, they've found something that breaks a law of physics as we understand it right now. It remains to be seen if it's true, if this result is replicable, and if it's not just a quirk in quantum computing as we have it now by itself. But if it remains true, cancelling the second law of thermodynamics, it's actually changing how we understand fundamental physics. And that could lead to a myriad of other ideas built on this, up to the point where time is no longer considered "an arrow", why systems no longer drift into entropy. If systems do not all drift into entropy, we would reverse the concept of cause and effect, of time as a one way in the sense of the effect happening before the cause, which essentially, is to reverse time. That doesn't mean we hop into our DeLorian, power up our Mr. Fusion, and get those 1.21 jiggawats (not in the beginning hehe), but it means we could probably see what happens now (right now) because we kick over a bike in ten years. That is a kind of divination (see this movie here for technological implications: IMDB Paycheck) ... if you understand what you'd need to do now to influence a system to run in the opposite direction, you could make things that happened... not happen anymore. If you'd knew now how to influence all the quantum particles you'd need to interact with, you could possibly do what's necessary to make Hitler not move to the other bunker for his meeting and Stauffenberg would have killed him, Gaius Julius Caesar would not have been stabbed, JFK not shot etc. etc. And as every equation that remains true is reversible, you could as well reverse calculate, that why things are like they are now, and see what this leads to because you'd need to find the cause of the current state of reality by it's cause in the future... hence calculating the future. As with every change in the foundations of physics, we are not yet aware of any implications or technical applications coming from such a principle, like after Einstein's theories became public, nobody thought that we'd get better GPS signals out of it. The people discovering magnetism and refining our understanding of it in the last thousand years also wouldn't have thought we'd have inductive heating in stoves at home right now. Saying all of this, I do not believe this is really possible, unless, of course, by using this method, reverse calculating the future and thus changing reality by acting appropriately, in that way creating a new quantum reality, hence, a new universe in the concept of endless parallel universes, the quantum multiverse.
The title seems overly dramatic. Reversing entropy for a tiny fraction of a second is not exactly reversing time - it would only be significant if such a reversal was sustainable and things went from disorder to order in general. Not really. It's been known that the laws of physics work the same regardless of the arrow of time (this is not a new discovery). The second law of thermodynamics describes the tendency of things going from a state of order to disorder, but there is nothing in physics that would prevent it from going the other way. In other words, the laws of physics won't prevent a cold cup of coffee from becoming hot again by itself - it's just very, very unlikely (so unlikely that we can basically rule it out). This discovery shows that we knew was possible - that entropy can reverse without violating the laws of physics, but I don't think it's a major discovery by any means. The quantum world generally behaves in ways that are difficult to understand (like the double-slit experiment) so particles temporarily reversing entropy isn't all that surprising. On a personal note though, I have often times thought about the possibility of entropy reversing one day and the universe folding back into a singularity. Perhaps experiments like this can show how that can be done.
bingo! Getting young for a fraction of a nano-second - I do it all the time Doing it consistently is a tricky part
I've found this strain that tests at 32.8% cannabinoid content....................................... ............................ ................... 1 hour later WTF was the topic again...
I've quoted this before and I'll quote it again: "Claim you can disprove gravity and I'll listen. Claim you can disprove Newton's laws of Motion and I'll listen. Claim you can disprove Second law of Thermodynamics and I'll say you're crazy!" said a famous physicist whose name I forgot interesting discovery regardless. Besides as said second law states (paraphrasing) all isolated systems tend towards their energy minimum (=maximum chaos / entropy). It does not therefore explicitly state the reverse would be impossible. It also implies that the reverse can be obtained but it requires bringing energy in to the system. Creating order from chaos requires energy input.
