LazyDave

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Brain Breakthrough! It's Made of Neurons!

It indeed cannot be objectively examined (afaik), but it can be subjectively examined, which is why I know that I have consciousness, but cannot say the same about anyone else. That being said, I do assign an incredibly high probability that others do indeed have it.

"3 Reasons It’s Irrational to Demand ‘Rationalism’ in Social Justice Activism"

Wow, I find that really surprising; I am hardly in tune with the "proper" terms one should use these days, but the flight attendant thing has been second nature to me for at least 10 years, and thought it was for everybody. I'd be really curious as to why you only became aware of it recently; do you not fly very often? I want to stress that I am not criticizing you or anything, my curiosity is just piqued.

"3 Reasons It’s Irrational to Demand ‘Rationalism’ in Social Justice Activism"

Yeah, I've noticed that when the word used for something is intentionally changed, oftentimes it is because the thing being referred to is viewed negatively by many. In addition, once the new word has widespread adoption, use of the old word is a signal that you indeed do view what it refers to negatively. A recent example is some politician who talked about what the NAACP should do if they wanted to help "colored" people; it was widely derided as a racist statement, even though he was simply expanding part of the acronym of the organization he was referring to. Similarly, afaik the word "retarded" was not considered pejorative back when it was in common use (nor was "idiot" a long time before that). The fact that "black" is still perfectly acceptable even after the introduction of "African American" gives me hope that there is a recognition that race relations are markedly improved.

"3 Reasons It’s Irrational to Demand ‘Rationalism’ in Social Justice Activism"

I'm not sure about its origins, but in the MSM I've only seen the term described as something members of the "alt-right" use to describe the group in question (obviously in a pejorative way), so generally when I use the term I enclose it in scare quotes (as I evidently do with "alt-right" for some reason), as I do not want to improperly signal that I hold certain beliefs.

Spooky Action at a Distance: The No-Communication Theorem

Thanks; sorry about the duplicate question post, I had not been able to find the "replay" version of this particular article.

[SEQ RERUN] On Being Decoherent

I think it is a good way to map what people have commonly called "superposition," but the sentence should probably be "The system is in the superposition STATE1 + STATE2, relative to STATE 3, where STATE 3 roughly factors out". STATE 3 in this case is usually an observer. I mean, if I flip a "quantum coin" and I have not told you if it is heads or tails, then the coin (and I) is in a superposition of "HEADS + TAILS" relative to you, but due to decoherence on my end, it is not in a superposition relative to me. For me this was an important concept to learn, as it helped me see that "many worlds" is a local and non-discrete phenomenon.

[SEQ RERUN] On Being Decoherent

And another quantum-related question. - In The Fabric of the Cosmos by Brian Greene (p. 196), he describes a setup of the two slit experiment where half of the particles have their "which way" information recorded, thus causing decoherence and not showing an interference pattern, and the other half of the particles are not measured, and thus do show an interference pattern. After the fact one can look at which photons were not measured, and these do indeed form the interference pattern.

However, he then goes on to explain an identical setup, with the difference that the decision as to whether to measure the 1/2 of the particles can be made many (light) years after the photons register on the screen, and only later, when the person making this decision light years away comes and tells you whether they measured or not, do you see if the unmeasured photons make an interference pattern.

This would all make sense to me IF there was no way to distinguish a totally non-interfering pattern, and a non-interfering pattern overlaid with an interfering one. Intuitively it seems like one WOULD be able to distinguish this, with a pretty high degree of confidence, by subtracting an "average" non-interfering pattern from the total pattern. Is this not the case?

BTW, I have been re-reading the QM sequence every 6 months or so since it was first posted, and get a bit more out of it each time. I am AMAZED at how it has explained things that, before reading it, seemed so freaky and inexplicable to me that it bordered on the supernatural.

[SEQ RERUN] On Being Decoherent

So this is sorta off-topic for this thread, but I cannot see where one can start a new one. I posted the following questions at http://lesswrong.com/lw/q2/spooky_action_at_a_distance_the_nocommunication/, as I cannot find the "rerun" version of it. Anyway, here goes. FWIW, the topic was about EPR experiments.

For all these types of experiments, how do they "aim" the particle so it hits its target from far away? It would seem that the experimenters would know pretty much where the particle is when it shoots out of the gun (or whatever), so would not the velocity be all over the place? In the post on the Heisenberg principle, there was an example of letting the sun shine through a hole in a piece of paper, which caused the photons to spread pretty widely, pretty quickly.

Does the polarization vector change as the photon moves along? It seems to be very similar to a photon's "main" wave function, as it can be represented as a complex number (and is even displayed as an arrow, like Feynman uses). But I know those Feynman arrows spin according to the photon's wavelength.

Finally - and this is really tripping me up - why can we put in the minus sign in the equation that you say "we will need" later, instead of a + sign? If you have two blobs of amplitude, you need to add them to get the wave function, yes? If that is not the case, I have SEVERELY misunderstood the most basic posts of this sequence.

Spooky Action at a Distance: The No-Communication Theorem

(I can't find the "rerun" version of this page, so am posting my questions here).

  1. For all these types of experiments, how do they "aim" the particle so it hits its target from far away? It would seem that the experimenters would know pretty much where the particle is when it shoots out of the gun (or whatever), so would not the velocity be all over the place? In the post on the Heisenberg principle, there was an example of letting the sun shine through a hole in a piece of paper, which caused the photons to spread pretty widely, pretty quickly.

  2. Does the polarization vector change as the photon moves along? It seems to be very similar to a photon's "main" wave function, as it can be represented as a complex number (and is even displayed as an arrow, like Feynman uses). But I know those Feynman arrows spin according to the photon's wavelength.

  3. Finally - and this is really tripping me up - why can we put in the minus sign in the equation that you say "we will need" later, instead of a + sign? If you have two blobs of amplitude, you need to add them to get the wave function, yes? If that is not the case, I have SEVERELY misunderstood the most basic posts of this sequence.

[SEQ RERUN] Can You Prove Two Particles Are Identical?

In a previous post in this series, it was stated that if you shot the particles towards the mirrors at different times, but that difference was vanishingly small, then you would still see the same results, except for there would be a correspondingly vanishingly small chance that you would see both detectors register a single particle, since configurations were "smudgy". Why would not the same apply to two electrons that were distinguishable, but their differences were vanishingly small?

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