joigus

The objection is expressed at 33:50 of the lecture I linked (without mentioning Dyson). If gravity were classical and gauge fields were quantum, you could beat the position-momentum HUP. Dyson's position basically is that Einstein's tensor is a classical field. But on the RHS of the equations you have the expected value of the energy-momentum tensor of quantum fields. You could, of course argue that there are <T²>-<T>² quantum fluctuations of these quantities, and thereby similar quantum fluctuations in the Einstein tensor. Yes, ER = EPR is due to Leonard Susskind and Juan Maldacena. I don't know about the state of the art of it, but it's a way to deal with quantum gravity that's being explored recently.

I stand corrected. Thank you, gentlepeople. Sexes there are < 10 Behaviours there are > 1000 Something like that.

This looks like homework...

Anyway. Sex is a biological fact that can be settled at cell-level. Behaviour is another matter. Sexes there are two. Behaviours there are millionfold.

In the Ricky Gervais sense? (Short):

Oh, yes. What Stanley Deser defined as 'denial' in this lecture: https://www.youtube.com/watch?v=Yh36XEX7yTk IOW, the gravitational field is one of a kind. Everything else is quantum. It's only gravity that's classical. Doesn't sound like a sound alternative. People have pointed to paradoxes and the like. And it's no surprise really.

This walks in the direction of what I was saying. GR as a theoretical standalone is not reliable to tell us what a BH (or any other trans-horizon-hidden singularity of the EFE) is telling us about. QM has to play a big role in it. Rupture of space-time, as if ST were some kind of elastic medium is clearly not the ticket. Every direction I know in which people are thinking has to do with generalising QFT to the appropriate degrees of freedom accounting for gravitation or proposing a unifying principle (EPR = ER) that achieves the concept-bridging between GR and QFT that everybody dreams of. There must be a reason why entropy has to be included in the mix, and it's almost a certainty that the reason has to do with QM. PD: From what I know, @Genady is right, and the singularity is a time rather than a spatial point. Assuming BHs are not better represented by other solutions that haven't been found yet and nobody knows anything about. Such is the plight of the non-linear physicist. But you're right. You shift to the E, t HUP and your point is still valid --at this point I don't know whether the pun is intended or not!! Sorry for the acronym shower.

Interestingly though, it has spawned a few questions: 5, and counting...

This is an outdated package of ideas otherwise known as Copenhagen's school. Decoherence is the key, not the observation, whatever that means. I don't think that makes much sense. Decay is already understood as an interaction, but not between matter and time, but mediated by W and Z bosons. What would interaction between matter and time even mean? Interactions, as we understand the concept, require a position representation.

Besides the more specific criticism you're getting, what part does QFT play in all this? It's extremely unlikely that any insight about big-bang, singularities, etc, would be obtained from classical GR alone without QFT playing any part in it.

Klaus Schwab? Is that you?

From what I've read, neuronal migration, glial growth, etc are perhaps the identifiable biological factors at work when the frontal cortex is developing (up until about 25 yo in most individuals) that are very much affected by the environment. Nurture and nature are both part of Nature because, as George Carlin once pointed out, Nature includes everything, including the oft-misused and abused figure of speech involved in the dichotomy nature/nurture. Developmental processes don't occur in a Petri dish. So I agree with most people's observation here, if I understood correctly: Remove the nurture factor and the genius disappears.

I hadn't read the last paragraph by OP. Well spotted, @exchemist. Fractals, GR, QM, knots, quantum computing. Space itself is moving. My BS detector went through the roof.

Maybe something to do with topological insulators? Any context I know where the word "topological" has anything to do with conductivity. It's some kind of interphase between conductors and insulator. It was worth a Nobel Prize relatively recently. https://en.wikipedia.org/wiki/Topological_insulator

Cyberspace is not a concept related to quantum mechanics.

What if "dead" was actually alive, and "alive" was actually dead? You know, as long as this is in "Sculptures made of Almonds"...

As to technical matters... Amplifying the coherent signal to enough qbits would be essential for quantum supremacy. Also, it would be nice to make them work at room temperatures. Last time I looked we were nowhere near that becoming a reality --let alone a household reality-- although I've been able to catch pieces of hopeful news about the first goal here and there.

And the "calculus" of it would be...?

Yes, your argument sounds right. I'll have to think about it over the weekend. Big workload now. Depending on how much Pinoccio has been lying, tidal forces would come into effect though. Thanks for the careful explanation. +1

Ok. If everything boils down to "there cannot be a backward photon" I think we all agree. But I have no time to think about it now. I still think Pinoccio cannot see the tip of his nose if he's facing towards the horizon, but he can if he's facing the other way, which is what didn't seem to me compatible with what Genady said in an extremely cursory way. It seems I misunderstood. I'll get back to it probably tomorrow.

Yes. IMO, this would be a "no", and I think @MigL's objection, still stands. Never mind your diagram. Frequency of backward-sent photon being zero. How do you detect a zero-frequency photon? Mind you, I might be obfuscated by ungodly-late hour at place of present statement. 😆

Absolutely agree with the first point. About the second point, I was thinking... How can you tell it's not noise? But then, if it's environmental noise that made them correlate the wrong way, there you go. They're definitely not entangled.

I think you're trying too big a bite there. Carbon gives rise to a very rich biochemistry, wich gives rise to homeostatic complex systems and approximate, but not exact replication thereof, which gives rise to a workable process of "improvement" (evolution), which gives rise to the possibility of projecting the external world in internal impressions of varying degree of permanence in cognitive tissue (as a great evolutionary advantage), which give rise to...[?] Call me reductionist, but that's how it works, I think. The chemistry of carbon is particularly suitable probably because 3D spatial arrangements with C-C covalent bonds afford much that other molecules wouldn't. Stability of the C-C bond being an obvious bonus. Carbon gives rise to a tetrahedral pattern of chemical bonds. Silicon has been proposed from time to time as an alternative, but I'm sure being further up in atomic number makes it less plausible. The chemistry and biology experts will no doubt take over and correct/expand on what I've said.

Strictly speaking, in order to make sure that photons are entangled, you would need: 1) Infinitely many pairs of photons prepared in the same way 2) Perform infinitely many measurements here and in the Voyager or wherever the other place is 3) Talking infinitely many times with the other experimenter and confirming that the correlations are the ones that correspond to such entangled state. The last step is called "sending the classical data" in so-called quantum teleportation experiments. Mind you: Nothing is teleported. It might as well have been called "quantum woodoo" and the phenomenon would be what it is: No woodoo at all, and no teleportation at all. In practice, the "infinitely many" can be substituted by "enough measurements" Measuring just one photon doesn't tell you anything about entanglement. Measuring just once on a pair of photons that are presumably entangled doesn't do anything either.

This makes no sense. And in fact it's usually the other way: The theory determines what to measure. Einstein famously pointed it out. It is because we have a theory that we can tell deviations of rotational velocity of galaxies from expected behaviour betrays excess density (DM), and certain measurements on supernovas confirms accelerated expansion. Those are parameters in the theory. That's why we expect those patterns, and we find them. Only rarely an experimental discovery comes completely from out of the blue. Although it does happen from time to time. An example from physics is the neutrino. I really think at this point you should take some time out for reflection.