Yet another thread on perception and reality. I think we have 20 threads now concurrently.

The physical world is a representation, an appearance, on the screen of perception, on the dashboard of dials. — Art48

Okay. Then what? What is the conclusion to this observation? Surely you don't mean this to be the conclusion.

“The physical world is not as the world as it is in itself. The physical world is a representation, an appearance, on the screen of perception, on the dashboard of dials. Physicality does not have standalone existence, a standalone reality, for exactly the same reason that the images on the screen do not have standalone reality.” — Art48

Keep in mind first of all that my grasp of quantum mechanics is at the level of an intelligent but relatively uneducated amateur. I understand the outlines of the theory and some of the consequences, but I'm not capable of judging in any detail or depth. In particular, I struggle with action at a distance as it is described in current science.

I watched the portion of the video you described. Kastrup uses the language of Kant; thing-in-itself, noumena. He also mixes in action at a distance associated with quantum mechanics. Kant's formulation is one that has parallels with other philosophers - Schopenhauer, Lao Tzu, and Merleau-Ponty I am aware of, but I'm sure there are others. These formulations are metaphysics. They're assumptions, what are called absolute presuppositions. They are not facts. They are habits of thought that form the foundation for science, but aren't science themselves. Quantum mechanics, on the other hand, is science - a set of theories established based on experimental and theoretical physics and then validated by further observations. These two ways of looking at things don't belong together.

Kastrup isn't stupid. I'm guessing I am misinterpreting his ideas. As I noted, my understanding of quantum mechanics is at a relatively unsophisticated level. But I don't know how to take this discussion any further.

It's worth noting that the OP refers to one part of one video, which is part of a series of video presentations comprising an entire course on 'analytic idealism', which can be accessed freely here. To get a fair idea of what Kastrup is talking about, it's probably better to be aware of the context, rather than 'kicking the ball around' on the basis of a brief excerpt.

Okay. Then what? What is the conclusion to this observation? Surely you don't mean this to be the conclusion. — L'éléphant

As I understand it, the soccer metaphor is meant to explain entanglement. The two entangles particles are analogous to the two views of the soccer game. The game itself is some higher or deeper reality that is somehow outside of space and time. Thus, in some sense, the two entangles particles naturally correspond because they are two different views of one thing.

Donald Hoffman has a similar view. He argues that space and time aren't ultimate; that they are somehow appearances of a deeper reality outside spacetime, that spacetime is part of our interface to reality.

Note: I'm not arguing these ideas are true. But I think they are interesting and may be true, which is why I posted.

Note: I'm not arguing these ideas are true. But I think they are interesting and may be true, which is why I posted. — Art48

I get your point. However, the examples of Donald Hoffman and the soccer metaphor are, to me, just variations of metaphysical views about perception. So, if I don't find these interesting, it's because I do understand the point, but not the motivation behind. Spacetime, for instance, has already been theorized as just mental construct that's limited in shape and form due to our finite existence. Nothing to gain by going against it.

But let's say the above examples are what actually is, there's nothing to change in our knowledge of the world since our knowing of it (spacetime is just a facade of the real thing) does not change our perception -- we will continue to see the world through our constitution. Our experience will remain the same.

I realize that what I've just written seems like nothing but two paragraphs of blah blah blah.

I don't find it "blah". It's reasonable to ask, So what?
Some religions build off of the thought that spacetime is a facade and define the real thing as God.
The task for the believer then is to try to see God in everyday life.
For example,
Why is the World False? https://www.youtube.com/watch?v=cwcft4auszA
Seeing the eternal in daily life not just in samadhi - https://www.youtube.com/watch?v=Wqw84fkHhk8&t=253s
So, the thoughts can have consequences if taken far enough.

I realize that what I've just written seems like nothing but two paragraphs of blah blah blah. — L'éléphant

Actually, I found what you wrote helpful to put the discussion in context.

There's something comical about presuming to give lessons of this kind on YouTube. I wonder what people really are seeing when they watch this video. Just a representation of a representation made by a representation of something the representation believed was represented, I suppose.

We're in the world. We're part of reality. It isn't something separate from us, that we observe. But this is old stuff.

There's something comical about presuming to give lessons of this kind on YouTube. — Ciceronianus

Where would you consider more appropriate?

:up:

Where would you consider more appropriate? — Art48

I'd prefer that there will come a day when there will be no further reference to an "external world" anywhere, anytime, if what is meant is some place apart from us that we can never "really" know. But we're so infected by the belief that there is a world "out there" that it's unlikely that blessed day will arrive.

Ain't it the truth.

We're in the world. We're part of reality. It isn't something separate from us, that we observe. But this is old stuff. — Ciceronianus

Panpsychism. :up:

The soccer game metaphor is presented from 5:00 to about 16:37. Imagine a soccer game as reality, as the thing in itself. The physical world is likened to seeing the game on TV, on two different TV channels using two different TV monitors. Each TV channel uses its own camera so the images on the two TV monitors correspond but are not identical. — Art48

Just to comment on the quantum mechanics:

The card shuffling idea is incorrect. I don't know where they get that from. It's necessary to keep track of each pair of entangled particles. It's only the particle pairs that exhibit the correlation when measured.

Also that the measurements perfectly correlate is not the puzzle. Since the entangled particles were prepared together, they could easily have had predefined values. No big deal.

The segment with the pink and green cubes also doesn't get at why anyone should be puzzled.

Throw in the notion that one's looking causes immaterial non-local influences, and I would expect the average person to be more confused after watching that film than before.

Also, the metaphor of the soccer match and TV's also doesn't end up addressing entanglement. There's really a soccer match. And the TV's (also real!) receive a local signal. No mystery there.

Regarding non-locality, most physicists reject it because it doesn't play nicely with the theory of relativity.

Also, the metaphor of the soccer match and TV's also doesn't end up addressing entanglement. There's really a soccer match. And the TV's (also real!) receive a local signal. No mystery there. — Andrew M

The two TVs represent the two measurements. The reality is the soccer match. Obviously, the images on the two TVs have to correlate as they represent two views of a single reality. I think the point he is making is that there's a deeper reality than the physical world and therefore it's no surprise if two measurements correspond.

they could easily have had predefined values. No big deal. — Andrew M

Isn't it the case that we know they do not have predefined values (unless we accept the pilot wave, Bohmian Mechanics interpretation)?

Do you like the following metaphor better than the game metaphor?

Suppose we have two spinning coins, separated by light years. Suppose if Alice causes her coin to stop spinning (analogous to doing a measurement) and it lands heads, that Bob causes his coin to stop spinning and it lands tails. Suppose Bob's coin always lands on the reverse side as Alice's coin. This is my metaphor for quantum entanglement as I understand it. Comments?

The two TVs represent the two measurements. The reality is the soccer match. Obviously, the images on the two TVs have to correlate as they represent two views of a single reality. I think the point he is making is that there's a deeper reality than the physical world and therefore it's no surprise if two measurements correspond. — Art48

Yes, that's the intention. However it's not surprising that the TV images correlate. Whereas quantum entanglement is surprising.

Isn't it the case that we know they do not have predefined values (unless we accept the pilot wave, Bohmian Mechanics interpretation)? — Art48

Yes, that's correct.

Suppose we have two spinning coins, separated by light years. Suppose if Alice causes her coin to stop spinning (analogous to doing a measurement) and it lands heads, that Bob causes his coin to stop spinning and it lands tails. Suppose Bob's coin always lands on the reverse side as Alice's coin. This is my metaphor for quantum entanglement as I understand it. Comments? — Art48

That specific example can be explained by a hidden variable theory (i.e., with unknown predefined values). When the two (quantum) coins were prepared together, one was configured to land heads, the other tails. Alice and Bob didn't know which way the coin they received would land until they measured it. But when they did, the hidden variables were revealed.

However to see why hidden variables are ultimately unsatisfactory, consider the following classical game (called the CHSH game):

Alice and Bob are in separate rooms with no way to communicate with each other. A referee in each room randomly flips a coin which the players see. Each player responds by saying "red" or "blue".

For Alice and Bob to win the game, their responses have to be the same if and only if at least one of the coins show heads. They can agree on a strategy beforehand.

The game is repeated many times. What classical strategy maximizes their probability for winning and what is that probability? Have a go at answering it, then check below.



Now let's try a specific quantum strategy. For each game, Alice and Bob share a single entangled particle pair. To match the responses above, I'll call the two possible states "red" and "blue" (in this case, Alice and Bob would both report the same color if they measured their particles at the same angle).

Alice and Bob agree beforehand to each measure their particle at an angle that depends on the coin flips. On heads, Alice's measurement angle will be 0°, on tails 45°. On heads, Bob's measurement angle will be 22.5°, on tails -22.5°. They each measure their particle and report the color result.

In three of the cases, at least one of the coins will be heads and the difference in Alice and Bob's measurement angles will be 22.5°. QM predicts that they will measure the same result cos²(22.5°) ≈ 85% of the time. In the double-tails case, the difference in Alice and Bob's measurement angles will be 67.5°. QM predicts that they will measure a different result sin²(67.5°) ≈ 85% of the time. Thus Alice and Bob win the game on average 85% of the time.

So the quantum strategy is better than the best possible classical strategy, violating the Bell inequality. That's Bell's Theorem (one of many variants). So at least one of the classical assumptions is incorrect (hidden variables, locality, or statistical independence).