General

Re: Logic should not be trusted.

Clayton — Tue, 03 Jul 2012 22:17:52 GMT

@Seraiah: Well, he's absolutely correct if by "universe" we mean "classical universe" - it is not possible that there is just one universe, which is classical, because classical mechanics contradicts quantum phenomena. The many-universes approach basically allows you to retain classical mechanics in each of an infinite number of branching, classical universes. Garret's point is that this is a metaphysically tortured way of thinking about the Universe. His alternative (which isn't actually that radical, cf Murray Gell-Mann and Seth Lloyd) is to simply deny that the Universe is classical at all ("zero universe" interpretation). He's being wry.

Clayton -

Re: Logic should not be trusted.

Seraiah — Tue, 03 Jul 2012 18:41:05 GMT

Clayton:
... whatever that means ...

Haha. Well I'm glad to see I'm not alone in not really understanding what a "qubit" is, but in the lecture the guy said there was less than 1 universe or more than 1, but there definately wasn't 1.
Did I watch the wrong lecture? x.x

Re: Logic should not be trusted.

Clayton — Tue, 03 Jul 2012 05:56:02 GMT

The problem I have is the conclusion,

Number of universes =/= 1

Garret says that the many-universes interpretation of QM - while the dominant interpretation - is actually unnecessary and formally equivalent to the QIT view of a quantum particle as a packet of information (qubit). If the world is "made of qubits" - whatever that means - then we don't need to talk about multiple universes anymore. So, Number of universes == 1.

Clayton -

Re: Logic should not be trusted.

Seraiah — Tue, 03 Jul 2012 05:18:48 GMT

Clayton:
There's nothing conjectural about the data at all.

It's not the data I've got a problem with (well assuming the math is correct as I don't have a twinkies chance in Hell of following it.)
The problem I have is the conclusion,

Number of universes =/= 1

While bizarre and interesting, this isn't exactly a precise assessment of the world around us.

If we are part of some sort of simulation, where's the user manual, where's the switch to turn off mortality, and most importantly, where's the lady in the red dress?

If we are one of a bajillion universes, take me to one of'm, or at least send a post card.

I'm being facetious of course, but my point is that if his theory is correct; Where are his predictions? What can we test? How can we use this knowledge? If nothing, then how does it pass as more than musings of intelligent men?

Re: Logic should not be trusted.

Clayton — Tue, 03 Jul 2012 04:23:18 GMT

As a tradeoff for believing we're all in the Matrix!?

Not quite. Merely that the most "natural" description of the microscopic world is information-theoretic, at least, if you accept this metaphysical construct you can dispense with the much more wild constructs that involve things like multiple, parallel universes splitting off at every point in time, and so on.

I think the key intuitions which are at stake here are our intuitive sense of the solidity of matter and mechanical causality. When you hit a baseball, the bat makes mechanical contact with the ball and force is applied to the ball by means of this mechanical collision. This intuition is so deeply embedded into our consciousness that human language virtually identifies causality with mechanical causality, that is, mechanical collision. Our models of gases envision the gas molecules as if they were "bouncing" off each other at higher or lower rates of speed corresponding to pressure, volume and temperature.

But the discovery of the vacuum and particularly the scientific study of electricity and magnetism in the 18th and 19th centuries made it unmistakably clear that causality in the physical universe is not exclusively - or even mostly - mechanical. The positing of a "gravitational force" had earlier hinted at the possibility of "action at a distance", that is, causality in the absence of mechanical collision (as a footnote, Newton explicitly notes in his writings that gravitational force is merely a phenomenal principle and is not a causal principle, a point lost on most modern scientists). In any case, by the late 18th-century, we now have causality being mediated by ephemeral waves traveling through a luminiferous ether in addition to the familiar mechanical modes of physical causation.

This is already a crisis in waiting. The physicists are able to shoehorn electromagnetic phenomena into the mathematics of fluids and they speak of electricity as a kind of "fluid" or "gas" by analogy. But once the photo-electric effect is discovered and found to be quantized, the theories start really cracking at the seams. How can continuous waves travelling through free space in some kind of rigid ether be quantized?

The traditional metaphysical interpretations of QM are all tortured - at least, all except the QIT view presented here by Ron Garret which, though definitely odd/counter-intuitive, is not metaphysically tortured. You do have to give up the intuition of the solidity of matter, at least, acknowledge that solidity must be an emergent phenomenon which is pervasive at the temperatures, pressures and scales in which we and our ancestors evolved and, hence, comprises the majority of our intuitions about physical causation but is not an essential aspect of the physical world and causality.

That was a fun lecture. Don't know what else to say. Quantum physics looks like alot of conjecture at this point.

What conjecture? He holds up the polarized filters showing quantum erasure in action. There's nothing conjectural about the data at all.

Clayton -

Re: Logic should not be trusted.

Seraiah — Tue, 03 Jul 2012 03:37:34 GMT

Clayton:
resolves the need to invoke wild metaphysical interpretations of quantum phenomena.

As a tradeoff for believing we're all in the Matrix!?

That was a fun lecture. Don't know what else to say. Quantum physics looks like alot of conjecture at this point.

Re: Logic should not be trusted.

Clayton — Tue, 03 Jul 2012 03:13:23 GMT

this new theory

It's not a new theory. Garret is a mainstream physicist who specializes in Quantum Information Theory. This lecture just provides a "reinterpretation" of quantum phenomena from the QIT perspective. In the process, you realize that thinking about a quantum particle as a "qubit" - a strange entity but no stranger than, say, the complex number field - instead of a billiard-ball or a wave resolves the need to invoke wild metaphysical interpretations of quantum phenomena.

Clayton -

Re: Logic should not be trusted.

Seraiah — Tue, 03 Jul 2012 00:10:48 GMT

Clayton:
I'm glad you noticed that...

Yay! :D

Clayton:
...because he makes no claims to debunk anything.

You sarcastic bastard. :(

It's hard for me to see how this new theory could explain away what we see in the delayed quantum eraser experiment, but maybe when I watch the lecture it'll make more sense...

Re: Logic should not be trusted.

Clayton — Mon, 02 Jul 2012 19:55:33 GMT

People almost universally say that, but I haven't exaggerated the results of the experiment. No one predicted what would happen when the first double slit experiment was tried; It was entirely illogical based on what we knew about the universe.

Not really. It was just "entirely illogical" based on a billiard-balls-and-waves picture of the microscopic world. That suggests that the microscopic world probably should not be thought of as billiard-balls-and-waves.

Edit: After reading through the slides it's apparent that he hasn't debunked anything.

I'm glad you noticed that because he makes no claims to debunk anything. He's simply pointing out that popularizers of QM project a misleading image of the irrationality/bizarreness of the quantum world that simply disappears when you think of a quantum particle as conveying a unit of information and apply the appropriate mathematical construct (quantum information theory) to it. You don't need "wave collapse" anymore, you don't need faster-than-light communication to explain EPR, hell, you don't even quantum randomness (it's just noise)! You don't need parallel universes and you get determinism and causality back. These are really interpretational or metaphysical issues, not empirical or even model-selection issues.

Clayton -

Re: Logic should not be trusted.

shackleford — Mon, 02 Jul 2012 13:25:20 GMT

When you observe an object, you're simply projecting the object into another eigenstate because of the energy input from your observation, assuming you have an object of low-enough energy, according to the uncertainty principle.

Re: Logic should not be trusted.

Seraiah — Mon, 02 Jul 2012 12:42:35 GMT

Clayton:
The supposed craziness of QM is overblown.

People almost universally say that, but I haven't exaggerated the results of the experiment. No one predicted what would happen when the first double slit experiment was tried; It was entirely illogical based on what we knew about the universe. Well, the story is longer and more interesting than I've put it... Oh wells.

Edit: After reading through the slides it's apparent that he hasn't debunked anything. It's interesting, but unless there's a prediction/experiment that could be tried to verify his claims, I remain unconvinced. Though to be fair retro-causality doesn't have a monopoly on the issue. *shrugs*

Re: Logic should not be trusted.

Clayton — Mon, 02 Jul 2012 07:38:18 GMT

Whether or not an interference pattern appears can be altered after the pattern should have already been decided.

But this is simply a confused way of thinking about the issue. Ron Garret explains how an information-theoretic view of quantum mechanics gives a perfectly rational and comprehensible picture of quantum erasure experiments. The supposed craziness of QM is overblown.

Clayton -

Re: Logic should not be trusted.

Luminar — Mon, 02 Jul 2012 07:01:28 GMT

@ Serpentis-Lucis

You're starting to go into unknown territory for me. I don't know any of those words (Foundationalism, Coherentism). I know logic and philosophy on my own terms, and it's worked nicely for me so far. I'm not sure how those affect my arguments; I just wanted a clear answer to my post.

What you said (and the context in which you said it) kinda felt like an ad hom. Just saying. Also, have you ever read Objective Knowledge?

Re: Logic should not be trusted.

Seraiah — Mon, 02 Jul 2012 05:55:25 GMT

JackCuyler:
You reversed the causation. It is not true because of testing or repeatability. It testable and repeatable because it is true. Whatever is true was true before its truth was verified through testing and repeat testing.

I'm glad you pointed that out, as it's perfectly logical thing to say. However, it has been scientifically disproven by the quantum erasure experiment. Whether or not an interference pattern appears can be altered after the pattern should have already been decided.

This illustrates my point that something perfectly logical and straightforward can in reality be experimentally false. Therefore one should not trust logic.

Symantically you can say it's not logic, but the underlying assumptions that should not be trusted, but at the end of the day we're saying the same thing; You cannot trust the product of logic.

And to get back to your point, that it's reversing causality, I'm not sure that's important. I'm not sure "Truth" exists outside conscious awareness, and again, would the universe look any different?

Re: Logic should not be trusted.

vive la insurrection — Mon, 02 Jul 2012 01:47:31 GMT

1. Occam's Razor could be false.

Probably been pointed out already, but I'm too lazy to read, and don't care to visit this thread again. I have no clue what you mean by this, but Occam's Razor is simply not a part of formal logic