@-Gnarlemagne

1 year ago

I just wanted to address a very common (and natural) misunderstanding some people are having! Lots of people think that what was creates was just a simulation of a black hole's singularity, but this is so much more than that. It's a bit of a read so buckle up! Disclaimer: I have spent a lot of time trying to understand this, but my own field of study only brushes up against quantum mechanics, so someone who is academically active in the field may be able to point out some inaccuracies in my explanations. There's two very natural misconceptions that lead to the idea that what they produced was not an "actual" wormhole, but just a simulation. The first misconception is that a wormhole only refers to the Einstein-Rosen bridge from the ER paper, which describes a theoretical wormhole created by the extreme curvature of spacetime in a black hole. The second misconception is from the fact that nobody does a very good job at explaining what a quantum computer actually is, and the fact that they are called 'computers' lends itself to the incorrect but understandable assumption that they are just simulating something. I'll tackle these misconceptions in order: ===WHAT'S THE DEAL WITH THE EINSTEIN ROSEN BRIDGE=== General relativity is probably the single most successful theory in all of physics. It describes space and time not as two separate things, but as a unified four-dimensional spacetime - and most importantly for this discussion, this spacetime has a bad habit of bending and skewing in the presence of concentrated, non-moving energy - or as we call it, mass. After they were mathematically proven to exist, black holes caused some issues, because the math that proves that the must exist, also completely stops working once you get to the singularity. The ER paper mentioned in this video proposed a very mathematically beautiful solution to this problem: Based on the foundation that spacetime can curve and distort, instead of concentrating energy to an infinitely small, infinitely dense point that messes everything up, a singularity must instead connect with another point in distant spacetime. This is what we usually think of as a wormhole, and one might mistakenly call an "actual" wormhole. However, I think we can all agree that anything that connects two points of distant spacetime would be a wormhole, so if you could create one through some OTHER mechanism, it would still be a wormhole - would it not? Up until recently, there was no reason to believe that there was another method through which an ER-bridge could be created through which something could move, so it would seem pointless to make the semantic point I just made above. In the EPR paper referenced in the video, Einstein, Podolsky, and Rosen, not content with the seeming violations of causality that quantum entanglement caused, proposed wormholes as a possible explanation for this supposed faster-than-light transmission of information - but as this bridge would not be able to move macroscopic systems across space and time, so it seems like a different idea, so it seems open and shut that you cannot have a real wormhole without gravitation. This is why the discovery of Dr. Maldacena in 1997 (4:56) and subsequent discoveries - that is, the theory of ER=EPR is so huge. It's incredibly complicated, and even if I was capable of explaining it all, this is all brand new physics that hasn't been fully fleshed out - but what it comes down to is that not only can entangled systems on a very small scale display properties similar to the wormholes in a black hole, they are exactly the same phenomenon. That means that wormholes are not just a phenomenon of gravity, but in fact a phenomenon of quantum mechanics, and that it should be possible to create a wormhole by entangling quantum particles on a smaller scale. So now we know that (if ER=EPR) we can create a wormhole by using entangled quantum particles in the right way... That sounds hard. Now what? Enter Dr. Spiropulu and her team. ===WHAT'S THE DEAL WITH QUANTUM COMPUTERS=== Quantum mechanics is complicated to say the least, so I'm going to assume you've made yourself familiar with some of the basics of it - at the very least, the idea of quantum superposition, i.e. that quantum particles can only be described in terms of where they might be according to a probability function, until "measured" - aka, until they become entangled with you, the observer. This is important. What quantum computing does is that it weaponizes these properties. It's extremely easily to accidentally interfere with a quantum particle and thus collapse its waveform, eliminating its quantum mechanical properties - but if you can avoid that by minimizing any direct or indirect interaction with it, by removing any air and supercooling the system down to superconductive temperatures, you can send an electron or photon through a hell of an obstacle course, basically a "circuit", and only collapse its waveform at the end, producing a quantum interference pattern that tells you every single way it could get through that circuit. In a way the famous double slit experiment is the first ever quantum computer, which asked the simple question "what different ways can a photon get through two slits" - and if you measured ahead of time which slit it passed through, you are zeroing in on a different, but related question: Of the ways a photon can pass through two slits, what subset of them involves passing through this one particular slit? It's not a particularly helpful question to ask if you're trying to compute something, but it IS a very helpful question if you're trying to understand the fundamental nature of quantum mechanics. See, that's what a quantum computer does: It is not a simulation of quantum systems, it is a system to build a more complex quantum system without collapsing the waveform, and then to observe the probability space that emerges. ===IN CONCLUSION === So what does all this mean for this video? To summarize, when they say they built a wormhole in a quantum computer, they don't mean they simulated a black hole. They mean they worked with Google Quantum to physically build a quantum system which was theorized to produce a wormhole and send an electron or photon (In this case an electron) through the system in such a way that it would create one interference pattern (probability space) if it traveled through a wormhole, and a different one if it didn't - and when the dust settled and they got the quantum system stable and looked at the interference pattern, it showed that they had in fact *physically created a quantum system wherein an electron passed through a wormhole*. So, in conclusion, I hope this convinces you that they did, in fact, create a quantum wormhole right here on earth :) P.S. There's a lot of other things going on here. For example, this whole thing about De Sitter space. I can't get into it now, but this is all consistent with expectations, and unfortunately does mean that we're probably not going to be zooping across spacetime through wormholes anytime soon. Still though, it's very cool.

292 |