joigus

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.

Prof seems to be one of the most-oft-misread people since Nostradamus.

This has been mentioned and references, etc., given. Mentioned also, and references given. Extreme pH I would expect to more drastically change properties of macromolecules. But I haven't thought about it. Amino acids are notorious for being acidic and basic at different pH's, so they have a multiple-point sigma titration curve, if I remember correctly. If you wish to introduce this into the topic, you're welcome to do it. Please, give references.

Neither can I. When I reached that point, I decided to go for a joke.

Sorry I wasn't clear. Thermodynamics is not a force. You have energy stored in macroscopic systems. But a big part of it is lost. It's invested in pushing and pulling, and shoving atoms against each other, and changing their rotational states, and so on. A small part of it you can use if you want, and you're clever enough to use it efficiently, and transform it into work (force times displacement). So there is a fraction that can be used as force. But thermodynamics is pretty much about no matter what you do, a lot of the energy content is unattainable.

Pressure times surface certainly gives you a force. That's thermodynamics. Does that help?

Who said this? Thermodynamics is not a force. Mess in the quote function, sorry. Here it is. There are differences between Helmholtz's and Gibbs' free energy --as said before. An example from non-equilibrium thermodynamics is the energy stored in ATP molecules in a living organism. They certainly can do work. An example from equilibrium thermodynamics is the slow expansion of a gas.

Oh, no. No!!! We will never see the end of this. It's like... who do you love most, your mum or your dad?, what came first, the egg or the chicken?, who was Jack the Ripper? Ok. My answer is...

"Counterdicing" sounds like something you would do to a potato or an onion, and very dangerous to your fingers.

As Swansont has pointed out, no. Earth's forests didn't thrive, e.g., during the Permian --globally, and long before humans existed--, and fought a battle to death with the big herbivores in the past --think of grazing dinosaurs. They're still fighting that battle. Animals like the elephant, deinotherium, mammoths, etc. are (and have been) largely responsible for forest disappearing in big patches. You also forget many other factors, like weathering of rocks (depletes the atmosphere from CO2), volcanism (fills the atmosphere with CO2 among other things). The other things you miss is what Beecee tells you: Milankovitch cycles are known to have an important effect in the cooling and warming cycles of the Earth. And Mikhail Budyko showed that, were the Earth to suffer a period of cooling hard enough for the polar ice caps to get to 25-30 degrees latitude, the albedo effect would be so powerful that the total freezing of the Earth would be unstoppable, reaching even the equator. So: is also incorrect in general, over geological-scale time periods. We know this happened in the past because there are regions in Australia and America where rock patters show that the sand was under a cover of ice, and yet, due to magnetisation patterns, we know they were on the equator at that time. This was previous to the Cambrian, though, and it is not believed that it would likely happen again.