joigus

Sorry, what are those? Very interesting. Thank you. Concerning the reason why we're so "tuned" to being pleased by sequences (or longer overlaps, as in chords) of frequencies that are related to one another by integer numbers; my guess is as good as anybody's. But I don't find it very surprising. What I find even more surprising is the fact that there seems to be this fixed reference of a central note. Anybody who's attended a classical music concert --or Renaissance music--, which I do quite often, is familiar with the protocol of all the musicians tuning their instruments to A major when the concert is about to start. What defines A major? Even more amazing, apparently there are people who have absolute pitch. I know about this because I have a friend who is a physicist and advanced piano player who has it. These gifted people can tell A major with no "external reference", so to speak.

An image is worth a thousand words:

There's an even more terrifying possibility... I'm sure it hadn't even crossed your mind.

Just for the benefit of other users who are presumably going to waste a lot of effort here. I already explained what makes musical notes special --a reasonably centrally placed A major, which is quite audible for a large range of people, but possibly arbitrary as to its exact value--, and then the harmonics, which are defined as integer multiples or fractions of it. Also gave hints that the question is very old --goes back to the Pythagorean school--. I equally argued that light is very different, because we don't intuitively perceive it as "frequencies of something oscillating", although it is, in the last analysis. Also hinted to the fact that when you play a note after another, they overlap, and you notice that they are in sync. All these points went unnoticed. The OP doesn't seem to care one way or another. In fact, this thread could well end up being about gravity. Who knows.

You're confusing levels of explanation. Light (photons) makes up what we call "to see." A very complex large-scale phenomenon. You don't "see" a photon (light). Photons excite receptors, and nerve impulses project those excitations in your visual cortex. That is what we call "to see." One single photon most of the time probably is not enough to excite a photo receptor. Sometimes we even see light where there is none: https://en.wikipedia.org/wiki/Phosphene Already the Pythagoreans noticed that humans find sequences of notes related by integer multiples specially pleasing. Why is that I'm not sure. I'm not even sure if anybody knows. But I think it's probably related to the fact that sounds are very low-frequency in relation to light. So you don't have a chance to time-resolve different kinds of light. Let me tell you what I mean. Heisenberg's principle (actually, a general theorem of Fourier analysis of waves) can be illustrated with a piano. It is well known that to make the pitch of a note more definite in you mind, it is necessary to make it last longer the lower the frequency is: \[\triangle\omega\triangle T\sim1\] Here \( \omega \) is the frequency bandwidth (in cycles per second), and \( T \) is a characteristic time that represents how long you have to let it last to make it distinct (a sort of "timewidth"). When notes sound one after the other, for a split second you hear them as a chord (before they die out) during the time they overlap in your hearing. Because sounds have much much lower time frequencies, your brain has a lot more of a shot to tell that something is "in tune" there. Not so with light. With light it's energy levels of molecules that have to do that job. You don't have this perception that something is oscillating more slowly or more quickly.

No: Reading what I said could be helpful.

Looks like @dimreepr got my point. Here's a graph of visible light: Do you think it's a coincidence that green --the frequency for which the human eye is most sensitive to-- is at the centre? The different "colours" have more to do with how cellular receptors get excited when they catch different frequencies. In the case of sound, we have a central value (for tuning instruments it's A major, if I'm not mistaken). This is a good central value, probably because most people can hear it distinctly. And then the other notes are placed where they are because their frequencies are integer multiples or fractions (base two) of that central reference "A".

You either missed my point entirely or are going off in tangents.

Do colours exist? Can you really say somebody is red-faced?

John Donne said that no man is an island, but you seem to be the exception that proves the rule. Quantum mechanics "is trying" nothing of the kind. x-posted with Studiot.

You may have just "discovered" quantum mechanics. Everything everywhere works as a wave. Right? We even have a name for that wave: Conduction band.

I agree. \( x^2 = -1 \) would be a different matter. But \( \sqrt{x} = -1 \) has one solution, which is \( 1 \).

Fiber optics works nothing like electrons in a wire. It's based on total reflection of coherent light at smaller than critical angle at which total reflection occurs. You can experience total reflection on the window of your home. Electrons don't go at the speed of light even in a vacuum, let alone in a conductor, as @beecee said. It seems you're confusing many things here. The black body radiation is in equilibrium with the electrons in it, which is a very different situation to conductivity. etc.

I don't think anybody ever doubted it. It's referred to thousand-of-years-old migration movements. That's all. A Korean family packing and moving to NY 70 y.a. is not included in there. Again: Unless I'm misunderstanding something in your argument.

Yes, it is. Otherwise the statistics don't make any sense. The whole founding hypothesis --Luca Cavalli-Sforza-- of tracking down ancient movements of population is based on genetic analysis of pockets of population that have interbred among themselves for millennia, so their genetic makeup is a telling clue. Otherwise you're mixing migrant Asians with ancestral Asians. Unless I've misunderstood something essential in your argument. The bone of contention is whether there was a pre-Clovis migration to the Americas. Hypothesis held by Dennis Stanford and others. This question was still hotly debated last time I looked at it.

You have brought up a brand of beer, sir, you have implied without proof that it exists, and I can think of few things nearly as controversial as discussing beer! Enough said! 🤣

The attribute of existence seems to be quite controversial...

Thanks a lot for bringing this to my attention. I'd heard about Boltzmann brains, but not about Helmholtz machines.

Well... It depends on... (Unfinished.) If you don't understand something, please ask. Welcome to the forums.

Good one. When an object casts a shadow that covers my shadow completely, has my shadow ceased to exist?

"in some sense" are important words in what I said. On the other hand, if you can mention anything that doesn't exist in any sense, I will answer all your questions. Harry Potter, the man I was or the dinner I ate yesterday, maths and concepts, a donut's hole, a particular region of space. Do these things exist? In a way, you are a new individual. I capture electrons and lose electrons constantly, the cells in my gut die every three days --if I remember correctly--, and in the end, electrons are just instantiations of a quantum field.

As Heraclitus and Take That (many centuries later) said, everything changes. Panta rhei. Nothing is the same, so in some sense, nothing exists. Or, as Antonio Machado said, Todo pasa y todo queda, pero lo nuestro es pasar, pasar haciendo caminos, caminos sobre la mar. My sorry attempt at a translation (though better than the one I've found in English): All flees and all remains, but our business is to flee, to flee while making our pathways, pathways traced over the sea. Good examples!

You read my mind, mate.

Isn't it blessed are the Greek? (as long as we're discussing philosophy and Life of Brian...)