What is Spooky Action at a Distance? - Ask a Spaceman!

Part 4! What are the basic lessons of quantum mechanics? What does quantum mechanics teach us about the nature of reality? How does a quantum worldview differ from a classical one? I discuss these questions and more in today’s Ask a Spaceman!


Keep those questions about space, science, astronomy, astrophysics, and cosmology coming to #AskASpaceman for COMPLETE KNOWLEDGE OF TIME AND SPACE! Music by Jason Grady and Nick Bain.

[Hbase]

You have a wonderful ability to communicate. Thank you.

[robgau]

I've got a gut feeling that, somewhere in the universe, someone has figured out how to travel at the speed of thought.

[steppenwolf]

I really appreciate your quantum series. Thanks.

[aforementioned]

I've watched this vid 3 times so far. So enlightening like always. Thanks.

[QuicksilverSG]

@6:10 "It appears that subatomic particles, when they become entangled, do influence each other, regardless of distance. And immediately you start asking, how can that possibly be?"

As you point out earlier, entangled particles cannot influence each other to the point of transmitting information faster than the speed of light, as that would violate the Theory of Relativity. But in the case of a spin measurement of one particle determining the complementary spin of a distant entangled particle, what actually enables that determination is your foreknowledge of the two particles' mutual entanglement at some previous point in spacetime. Even at that, the most you can state with certainty is that if those two particles were still entangled at the time the spin of the one particle was measured, the complementary spin of the other particle could be correctly deduced.

In reality, however, mutual entanglement doesn't enable separated particles to influence each other at all, because there is no such quantum action-at-a-distance mechanism that can do so. Where quantum entanglement actually manifests is not across physical space, but instead among particle superpositions that evolve according to the Schrodinger Equation in the quantum wave function. This wave function is defined in Configuration Space, a complex-valued domain of potentially limitless numbers of dimensions. Unlike physical space, events in Configuration Space propagate instantaneously (i.e. non-locally). When one of the particles is tested, the measurement apparatus becomes entangled with it in Configuration Space, and simultaneously affects the state of that entire entangled system of particles. The outcome of that measurement is then probabilistically projected from Configuration Space into physical space according to Born's Rule.

Consequently, the state of each entangled particle is not predetermined, as in Einstein's "spooky action at a distance", nor is it transmitted between particles across physical space. It is instead the entanglement of the measurement device with entangled particles in Configuration Space that produces correlated quantum events that are instantaneously projected into physical space, where we may then observe them.

[GeorgesvanDelft]

Hi, thank you for your great videos. I was wondering if you could make one about why all electrons or other "particles" are exactly the same. This is driving me crazy. As humans we are not able, despite all the advances or how hard we try, make 2 identical items, to an incredible level of precision. Yet in nature, all the fermions are identical. Thank you

[AlanMGross]

Thank you. I think there's something missing in your example of the two electrons being brought close together. At what point do they become entangled?

[davecurtis]

i'm enjoying your quantum series.

[ohasis]

I just clicked the thumbs up all the way from Australia. How's that for spooky action at a distance?

[matantamir]

Love this type of content, keep up the good work!!

[garrycollins]

I see a sci-fi story there. A drone is entangled with another. One is sent across the universe the other stays behind as the controller.

[isaacplaysbass]

Spooky Action at a Distance is the kind of thing that starts to make one paranoid about the possibility of Simulation Theory; perhaps entangling particles works because there's a software bug in TheUniverse-version-x.y that causes the entanglement process to reset the particles to a particular state/formation.

Then I realise - that's more of a philosophical paranoia, and we can simply get back to learning about how this place ticks :)

[mcpr]

You know that experiment where you use a beam splitter and make one path longer than the other, then shoot a single photon through and show the interference pattern proving it interferes with itself? I think this is a consequence of the photon not experiencing time.

Well, what if the path was so long that it stretched light seconds/minutes/hours, and someone on the far end had a mirror pointing back to your detector. Could this person transmit information back to you FTL? If the photons were sent on a steady period, the person could relay 0s and 1s by blocking or unblocking the mirror and you'd see an interference pattern or not, and only have to wait for the shortest path photon.

This has to be too good to be true right? So why wouldn't it work?

[antipoti]

Important to note, that although some kind of "information" is shared by the particles between eachother instantly, there is no way to use it to transmit actual information faster than the speed of light using entanglement.

[mdavid]

If you look backwards in time to beginning of the COSMOS...would everything be entangled?🤔 Would the past light cones of everything overlap?🤨

[russellneitzke]

Quantum mechanics proves intuition about the universe is not enough to understand it. We can't see inside a black hole but we can take what we know and simulate the inside. We can simulate the universe. All of our data that we collect can feed the simulation to refine it.

[quantumdave]

Finally! Someone explains it clearly 🎉. There is no telephone line between them…they are synchronized! Proof of true non locality would require real time manipulation and observations

[BC-lfom]

With my beer mug nearby, I am wondering: are all the electrons in that mug 'entangled' with each other? Just by being part of the mug?

Then, how do we know if a given electron is in a 'Entangled State' or not?

Also, since sub-atomic particles are so tiny, it is puzzling how experiments re: entanglement can be arranged and observed.

(Before I forget -- is beer with entangled particles superior to un-entangled beer ?)

Thanks for Spaceman presentations.

[aforementioned]

OK, but what if I separated the entangled particles into two rooms 10 feet apart and then at the same time, using an atomic clock to judge the time, looked at both particles at the same exact time. Which Particle influenced the other? Who measured first?

[wesmartino]

I don't understand why it's not considered ftl communication. Knowing the properties of both collapsed entangled particles is an epistemological issue. We don't know until we check. Why is it then assumed to also be ontological? Just because we have to check for our knowledge doesn't mean the particles aren't communicating at ftl speeds.