On Thursday, November 7, 2024 at 4:53:37 PM UTC-7 Brent Meeker wrote:
On 11/7/2024 2:28 PM, Alan Grayson wrote: On Thursday, November 7, 2024 at 3:22:53 PM UTC-7 Brent Meeker wrote: On 11/6/2024 12:40 PM, Alan Grayson wrote: On Wednesday, November 6, 2024 at 11:31:03 AM UTC-7 John Clark wrote: On Wed, Nov 6, 2024 at 4:23 AM Alan Grayson <[email protected]> wrote: *> An effect between entangled pairs but no information sent? Doesn't make sense. AG* *It's weird but it does not produce a logical contradiction. Suppose you and I have quantum entangled coins, I stay on earth but you get in your Spaceship and travel at nearly the speed of light for a little over four years to Alpha Centauri, then you slow down and start flipping your coin and I do the same on Earth. We both write down a record of all the heads and tails we got and both of us conclude that the sequences we got are perfectly random. Then you get back in your spaceship and four years later you're back home. And now that you're back we compare our lists of "random" coin flips and we find that the two sequences are identical, we both got the same "random" sequence.* *That's very weird but neither of us noticed anything was strange until you got back, and that took over four years because Alpha Centauri is four light years away. If we try to use our coins discern a message by Morse code with heads meaning a dot and tails meaning a dash it won't work because your coin will only come up the way you want it to 50% of the time. You could of course force your coin to come up heads or tails, but if you did that you would destroy the quantum entanglement because it is very delicate, and then you would just have two ordinary unrelated coins. * Two observers can't send information to each other because neither knows what will come up in a coin flip if the outcome is modeled quantum mechanically, that is irreducibly random , but each element of a pair of entangled particles can send information to its partner, since if it couldn't, they wouldn't be entangled. AG First of all you need to realize that "entangled particles" is just shorthand. Particles aren't entangled. Some property of the particles is entangled, e.g. spin or momentum or position. So in Hilbert space, instead of there being two different vector components for the spin of A and the spin of B, there is only one vector for the spin of both A and B. So Alice can measure it and B can measure it. But neither can change or control the measurement. It's random. Brent Yes, I am aware of that. Alice and Bob can't send messages to each other. But does either of the particles send anything to the other? That's the issue. It's called an "effect". But an effect must have some actual content, if it exists. AG The "content" is they share a vector in Hilbert space. Brent Have you ever seen a vector in Hilbert space? AG -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/9379db13-c9a7-41dd-9a2f-5ac4c1e9d841n%40googlegroups.com.
