joigus

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...)

Let me just correct you about something: This is not really an argument, if you think about it. It's a statement. I think you mean that wielding it in order to prove something, right or wrong, is flawed. I'm not familiar with Wittgenstein's argument, but I'd be very interested to know. Perhaps @Eise knows. He's our on-call philosopher. You and I probably are. I don't know about "all".

I'm not sure. You probably know more about Wittgenstein than I do. But then again, I'm a junk philosopher.

Nice tip. Would 1) save to PC, 2) edit with the Gimp, 3) Export to JPG, do the trick? Or do you recommend to strip metadata by "brute force", e.g., with ImageMagic or similar?

John, it's not my intention to prove you wrong, any more than it's very often my intention to prove myself wrong, for the sake of clarity and accuracy. Very often I take a back sit, click on the "follow" button, and try to learn from others, as you can easily check on the website's interface. There are many threads on which I'm just a follower. I strongly recommend you to carefully distinguish hostility towards you from rejection of your ideas, or even just honest intent to clarify your expression so that others can understand you.

(My emphasis.) Yours? This is not your thread. The OP was, Why don't we wait until the proponent clarifies what they meant? You can pose your own question if you wish, or maybe a split is in order. In any case, I don't think these shades in meaning about the verb "need" belong in the Classical Physics forum, TBH. Not so. OK as in "OK, I understand what you mean now". And it's wrong. That kind of "OK."

50 years studying viruses and he's come clean. Quite a feat!

Thanks for the clarification, @studiot. I've checked the online version of Oxford Learner's Dictionary of Academic English, and it seems to be the case that in modern English "something or someone needs + gerund" doesn't carry any special figurative value. But to me, it gives some leeway to be used in a sense that lets anthropomorphism of inanimate things slip in, which is not the best for a scientific discussion, as pointed out abundantly on this thread by many.

OK, then. But I think you should be aware that you're using language in a very special (figurative) way, as in "this room needs painting".

Then you concede that it's life that has needs, not the planets, as others are trying to tell you. Or is it the case that planets need life so that they can need something?

Mars needs global warming more badly than Earth. Some comments here strike me as very discriminatorily anti-Martian. And Venus could use some air-conditioning.

What's life without some humour, professor? I think it's the only thing that redeems us a little in this valley of tears.