joigus

Also, I don't see how you could have a sphere of charge change its radius while keeping it uniformly charged. Uniformly in space while the charge density changes with time? Any "realistic" model I can think of would produce radiation, as compressing the charge to a smaller volume would produce repulsion, and thereby, acceleration.

It's dark energy that pushes everything away, not dark matter. Dark matter does the opposite. Google for "dark matter caused the formation of galaxies". Dark matter is thought to be essential for structure formation in the very early universe.

I think you're probably right about this. Factoring in all that could be significant might be even impossible. Let's not forget that fiat money is no more than 3 % of the total amount of money in circulation. Of course, doing a 10-million-dollar transaction from A to B by sending datagrams over a network is much less energy-costly in terms of CO2 than having the same amount of money move in cash. But still, it only adds to all the factors that you've mentioned.

Here's a Bill Maher video, totally unrigourous, humourous, on the problem. I don't think it's a particularly impressive analysis of the problem, but it highlights some of the central questions. The main points being: A) CCs are based on nothing of "real" value B) CCs exert a huge demand on energy resources I think the second point is more or less right, but the 1st one, IMO, is not. I think Warren Buffett --and Maher with him-- misses the point of what the real problem with crypto-currencies probably is. It's not that crypto-currencies have no "real" value behind them (whatever that means). I don't know what "real value" is supposed to mean: Whether the actual cost of making it, which is next to nothing; its face value, which depends on socio-economical convention; or perhaps its purchasing power, which depends on how much money is circulating, as well as on the whole amount of goods and services available. I'll try to explain what I mean: Seigniorage (difference between face value and production cost of a monetary unit) of 1-dollar bill is 95 cents, if we're talking about paper money, which is practically the whole dollar. If "real" value is seigniorage, then it's arbitrary; if it's cost, it's just 5 cents; if it's purchasing value, it's highly volatile. It is ridiculous to think that money holds an objective value based on something real, in the same sense that machines, raw materials, qualified professionals, or energy sources are real. For digital money the cost is even less, I suspect, as it implies practically no extra cost writing 1'000'000'000 (a billion) instead of writing 1. In fact, crypto-currencies have a far safer system of controlling how much money is in circulation (a priori, at least) than the present monetary system has, resulting in a practically watertight framework to avoid inflation by dishonestly flooding the market with currency at any point in the network. And they also have an intrinsic value at least comparable to digital debt money (money just issued by writing numbers on a computer whenever banks "lend" money). I think the real problem with CCs is: 1) It creates yet another "bag" for inflation, encouraging people to massively invest in assets that may or may not fulfil their expectations of future returns. 2) It does so at the expense of a huge demand of power due to computational needs. 3) It does not comply with the criteria for sound money: Reasonable degree of; 3a) Scarcity; 3b) Standardization (accepted by many) If you create arbitrarily many types of money, you lose point 3b); and point 3a) becomes moot. What was intended to be safe money becomes investment in stamps. IMO, it's not worth the carbon footprint that it costs at the scale and with the rules of the game under which it's running, and it is at least in that sense that we all pay the price. I'm sorry that half my arguments are economic --thereby off-topic strictly speaking--, but that aspect is very much linked to the roots of the problem, and needs attention.

I think this is an interesting question. Energy is scarce (or world population puts enormous pressure on any level of energy availability at current time). Introduction of technologies that enormously increase demand of energy create inflation by way of increasing price of scarce resource. Inflationary movements can be seen as resulting in all people in need of energy (everybody) ending up paying a much higher bill for same amount of real resource. Inflation hides this effect of paying more by distributing load on whole populations, rather than reflecting its effects on an individual-by-individual way.

I think I've seen one of those somewhere.

Just to add to the mountain of very sound objections. I'm curious: How do you explain muon decay as a property of chains of protons? What about mesons? What would Tesla have to say about that?

Doesn't look like a very functional clock, does it? But still, when in Rome do as the Romans do.

To think how many dogs have had to put up with this shit... Last joke for today...

Nice account, by a top man in the field.

Good point. I think before the universe was vacuum-dominated, the calculation with just energy density of matter and radiation works quite well, and you can actually do the calculation by Newton's gravitation, the result giving coincidence between Schwarzschild's radius and radius of observable universe. I suppose you could do the trick of including an additional term to the total content of the energy by adding vacuum energy, then you would have to recalculate Schwarzschild's radius and everything would check again.

I think this belongs in the Brain Teasers section.

Erm... EM waves have no De Broglie wavelength. Their EM wavelength would not make much more than a few meters? There goes your teleportation. Tunneling is not teleportation. It's about things getting past classically forbidden energy barriers. And it has attenuation: the probability amplitude at the other side is much weaker than in the classically allowed region.

Black holes do not exist. This must be a peanut:

Where there's a will, there's a way. And even where there isn't exactly a will, there may still be a way.

Quantum tunneling is not free from attenuation. Look at this Wikipedia animation, for example: Also, quantum tunneling happens just next to the barrier, not far away. It's a completely different effect. https://en.wikipedia.org/wiki/Quantum_tunnelling

I was referring to the usual, i.e., speaking over the phone. Correlations at a distance are not magical, or anything new. But these correlations have to travel from Alice to Bob. Quantum correlations in entangled states are of a different nature. First of all, and most important, the word that Alice sets in her system is random. It's not like she can decide to send the word "ALERT" to Bob. That would be a code in binary 0100101101... etc. that she chooses. But she can't do that. All she can do is pick a spin projection --that much she can choose-- and see what word her system produces, which sometimes will be 0101001101..., other times 1101001000..., etc. Then she knows that, provided Bob has his magnets oriented in the same direction, he will measure 1010110010..., 0010110111..., etc. (the "complementary" words). She gains knowledge about Bob's state automatically. But the salient state is random. And were Bob to measure a different projection of spin, their respective states would be as uncorrelated as if they had never been in contact. This is a bit like a system that scrambles random words, so that the other user has the key to unscramble the message --the key being the particular projection they're going to measure--, but the words being completely random sequences --non-messages. What the uses of this technology would be, I don't know. But it's not completely obvious to me how they would take advantage of this technology.

Correlations at a distance is not synonymous with "entanglement". We experience correlations at a distance every day. In quantum entanglement it is essential that there is an observable "number of particles" so that you can tag particle 1 and particle 2. The quantum state is an arrangement of 2-particle states that cannot be factored: \[ \left|12\right\rangle -\left|21\right\rangle \] You cannot do that with classical fields. Also, certain polarisation choices allow you to contradict classical logic. If A, B, and C are certain statements "the car is red", or "the pencil is upwards", or anything you can conceive classically, you always have: \[ P\left(A,\neg B\right)+P\left(B,\neg C\right)\geq P\left(A,\neg C\right) \] Read: Probability of statement A and not B plus probability of statement B and not C is greater or equal to probability of statement A and not C. This is just as long as you can write properties A, B, and C as having a certain unknown value at the same time. Something like this: Quantum mechanics contradicts this. There are certain observables that you can pick for which QM predicts: \[ P\left(A,\neg B\right)+P\left(B,\neg C\right)< P\left(A,\neg C\right) \] I know of no example of mechanical rods or any other classical system that can reproduce that. I also think the complex-number character of quantum amplitudes has a lot to do with this.

I would tend to develop the argument along these lines. When someone puts forward a theory, there is an honest attempt to explain what we see or measure (let's call that "real"). But then it never stops at that; there are all sorts of concepts that are logically necessary to make the theory consistent. Taking up on your analogy with the map and the territory; we could ask: Are Meridians and Parallels real? I don't think anybody would say they are. They're just part of the theoretical scaffolding. There are no lines there, really. In the case of (perturbative) quantum field theory, if you want to describe a particle going from A to B, you always need to include these corrections due to particle-antiparticle pairs (fermions) being produced and re-absorbed before the particle reaches B; or standalone bosons being emitted and re-absorbed. They may just be a consequence of the way in which we partition the world with our theory. If some day people find a non-perturbative formulation of QFT that's entirely consistent and general enough, it may be the case that we can get rid of the concept of virtual particles entirely, and then we see them as just a contingency of the model of perturbative quantum field theory. The whole rationale of perturbative QFT is that I write down a dynamics that I can solve exactly, and then add smaller and smaller corrections based on calculational convenience. Why should Nature care about what we find easier or more difficult to compute? So maybe virtual particles are a consequence of our theoretical mapping, if I have understood you correctly.

I hate to corral people into these categories. You miss so much detail of the human landscape. @swansont with license to kill. I can see how that image has been burnt in your memory.

That's nothing. The iron in your blood carrying oxygen to your brain, so you can type, was born before the Sun was born.

Good members of the community helping along until everything makes sense and OP helping clarify own question. Business as unusual. Thanks to everybody involved.

https://en.wikipedia.org/wiki/Zeno_of_Elea https://en.wikipedia.org/wiki/Archimedes It's OK to confuse two guys who've been dead for more that 2000 years. I love the title of your thread "Want to know". I'm there.

No. And yes. They are very contingent concepts. As... perhaps most other concepts? "Exist" is not a good verb for describing reality, in the last analysis: Does the upper part of an electron exist? Does that look in my sweetheart's eyes exist? Does a name that hasn't been pronounced exist? Virtual particles are effectual, I would say. They don't exist, but they appear in calculations. If you measure their presence, then they "exist", but they no longer are virtual. That's the kind of circle we're in. And I don't know whether that's a satisfactory explanation, but that like the best I can do.