2 ms·

Can someone enlighten me: what is this simulator they speak of? It doesn't seem answered anywhere in the article what it is, whether it's software, let alone ho

by stinos 12y ago

Can someone enlighten me: what is this simulator they speak of? It doesn't seem answered anywhere in the article what it is, whether it's software, let alone how it works. Yet the whole article relies on it. Does it act on real protons? Or are they simulated as well? And, most important, why do they trust a simulation device built by humans who hardly understand the matter completely, when the device is then used to make assumptions about that same matter? Is it somehow proven this simulator is correct? And how did that happen?

jessriedel 12y ago
This is a poor article. It is reporting on a simple table top device created by researchers eager to misrepresent their work. It tells us essentially nothing about quantum mechanics or CTCs. We don't know how quantum mechanics behaves in the presence of CTCs. There are multiple, mutually incompatible proposals for extending QM in this regime that all make identical predictions in normal, causal spacetimes (i.e. the only sorts of spacetimes we have access to). Deutch has one extension of QM, and it suffers from serious internal consistency problems, but there are others. Since this experiment takes place without CTCs, it can't tell us anything we didn't already know. It's literally just a toy device that is sorta described by the same math as a certain system with CTCs in QM_Deutch would be, if you squint your eyes hard enough. But you could say the same thing about a computer simulating QM_Deutch in software. It tells you nothing about whether the universe actually obeys QM_Deutch in the presence of CTCs ... if they exist at all. Similarly deceptive bits of "research" in the news often appear that claim to find quantum gravity effects on table-top experiments. http://www.space.com/5052-black-hole-effect-created-lab.html http://www.space.com/5052-black-hole-effect-created-lab.html In all these cases, the scientists will eagerly over-represent their work to the journalist, and the journalist will eagerly gobble it up and write eye-catching headlines about new breakthroughs in physics, but the heart of the claim will be buried in the article and subtly couched in weasel words. And if you actually try to drive down at it by asking probing questions, the journal and scientist will retreat to much, much less exciting claims and you will never be able to prove they intended otherwise.

by stinos 12y ago

jessriedel 12y ago

This is a poor article. It is reporting on a simple table top device created by researchers eager to misrepresent their work. It tells us essentially nothing about quantum mechanics or CTCs. We don't know how quantum mechanics behaves in the presence of CTCs. There are multiple, mutually incompatible proposals for extending QM in this regime that all make identical predictions in normal, causal spacetimes (i.e. the only sorts of spacetimes we have access to). Deutch has one extension of QM, and it suffers from serious internal consistency problems, but there are others. Since this experiment takes place without CTCs, it can't tell us anything we didn't already know. It's literally just a toy device that is sorta described by the same math as a certain system with CTCs in QM_Deutch would be, if you squint your eyes hard enough. But you could say the same thing about a computer simulating QM_Deutch in software. It tells you nothing about whether the universe actually obeys QM_Deutch in the presence of CTCs ... if they exist at all. Similarly deceptive bits of "research" in the news often appear that claim to find quantum gravity effects on table-top experiments. http://www.space.com/5052-black-hole-effect-created-lab.html http://www.space.com/5052-black-hole-effect-created-lab.html In all these cases, the scientists will eagerly over-represent their work to the journalist, and the journalist will eagerly gobble it up and write eye-catching headlines about new breakthroughs in physics, but the heart of the claim will be buried in the article and subtly couched in weasel words. And if you actually try to drive down at it by asking probing questions, the journal and scientist will retreat to much, much less exciting claims and you will never be able to prove they intended otherwise.