Very professional work, thank you!

very nice to see these concrete examples

Great video! Much clearer than the original paper 🙂 A correction: the state shown under Step 4 on screen around 6:00 mark shows is not normalized correctly; the last two terms should have 1/√6 for coefficients.

@maria_violaris

5 ай бұрын

Glad you like the video! And yes that’s right, good spot for the mistake in normalisation :)

Lucid Explanation, well done.

Intresting..

I think the issue with this experiment, as you describe it, is that measurement is used two ways--one where you create an entangled state reversibly, and one where the states are measured irreversibly. If you do this, then you can easily get confused with regards to what is measured and when. I think it is much more useful to have a separate word to describe the reversible entanglement creation (I call it tagging in my classes, others call it premeasurement), and then it is clear in this example that neither Alice, nor Bob actually measure anything. They simply create entangled states that Charlotte and Daniel measure. So, by simply constructing the full superposition state for all qubits just before measurement, one can easily determine the possible outcomes. And there is never any contradiction. This is also related to your earlier video on Wigner’s friend analysis, where both forms of “measurement” were equated as being the same. But, they are not. If I create an entangled state, I do not know what I will get if I measure. I have to actually do the measurement (irreversibly, of course). Only then do I have a result and I can say this is what happened for this particular shot. I am, of course, basing all of this in a Copenhagenist fashion, with the quantum formalism being thought of as the mathematical tool to calculate probabilities, and not as the quanta themselves.

@maria_violaris

6 ай бұрын

Hi! I explained the empirical differences between treating an observer’s measurement as the observer becoming reversibly entangled with the system vs the observer irreversibly projecting the system into a single state in my previous video, on testing many-worlds against Copenhagen: kzread.info/dash/bejne/X415z7Shn8rHg7Q.htmlsi=J4cr15-5BsyhjI6m. In this video, I am not anywhere considering the case where observation causes some kind of irreversible collapse. I am fully treating the observers as quantum systems, hence their measurements must be described by reversible entanglement. The original paper proposing this paradox claims that even when all the observers are treated as fully quantum systems, with reversible measurements, there are contradictions between their deductions and the outcomes of quantum theory. That’s the claim I am addressing in the video. Hope that helps!

Let's assume a conscious observer can be represented by the human brain, with some sensory device attached (like, for example a couple of eyes). Why should it be impossible, even in principle, to have complete quantum control of such a system? I understand that it's (maybe) practically impossible, and also that freezing a real human brain to near zero Kelvin temperatures will destroy the brain, but those are more practical problems, aren't they? Roger Penrose assumed in his book "The Emperors New Mind" that quantum mechanics was necessary for consciousness, but that claim I think most other researches have refuted, and since the human brain is a warm and "messy" place from a quantum perspective, I would assume that all "gates" in that system are entangled with the environment, and so there is no quantum control or quantum computing like environment. But if consciousness is just a function of the amount of logic and memory in a system, and not something novel, then I would assume that in principle one could build a conscious observer with a brain that is cooled to near zero Kelvin temperatures, and where every neuron in the brain is a a set of quantum gates?

i reached the limit of my intelligence