RolfAndreassen

RolfAndreassen's Comments

Open thread, May 15 - May 21, 2017

The free market can't be always pushing down the price of all goods (measured in other goods), that's a logical impossibility.

And yet that seems to be precisely what has happened.

However, supposing we hold tech progress and capital investment constant, then yes, we'll reach a steady state in which prices as a whole cannot fall further. But that still does not demonstrate that it is possible to maintain the sort of high-value-extraction transactions you outline for any great length of time. If the profit of bread is high then it will fall as people enter the market; this will, yes, slightly raise the profit of all other occupations, holding technology and capital steady. But the eventual equilibrium has all the profit rates being the same. Otherwise investment flows from the low-profit ones to the high-profit ones.

Open thread, May 15 - May 21, 2017

It seems like you have just reinvented the criticism "if you can extract almost all the value from each transaction (aka 'exploitation'), you will shortly be rich". Well, yes, but the point is that a market with competition generally prevents you from doing that. As someone pointed out, if you make 100 loaves then you have created 100 dollars of value; the question is how those 100 dollars are distributed. You construct an example where the baker is able to capture 99% of the value he created; good for him, but it relies on your construction of the price. Seeing the baker get rich, won't a bunch of other people decide that bread-making can't be that hard, make some loaves, and sell them for 98 cents? And so on until the price of bread is equal to the cost of production plus the smallest profit anyone is willing to live with, which in your example seems to be a penny.

Open thread, Apr. 17 - Apr. 23, 2017

It's disrespectful to people who don't have any food to eat, much less play with. Food is important, and this fact is easily forgotten.

5 Project Hufflepuff Suggestions for the Rationality Community

Idea 2 seems very vague. Can you give an example of how I would use it?

A great articulation of why people find it hard to adopt a naturalistic worldview

There seems to be some implicit premise along these lines: "When contemplating the 'arrow of time' we should not consider anything that doesn't explicitly appear in the laws of physics." but I don't see any reason to accept such a premise.

I would say "explicitly or implicitly", and then it seems to me that we have every reason to accept that premise, because where the Devil else are you going to look? Noting that entropy does not appear in the laws of physics even implicitly; it's a heuristic, not a derived quantity.

If I talked to a bunch of theoretical physicists -- a group whose intuition in such things I think we should probably trust more than that of either experimentalists like you or pure mathematicians like me [...]

I would rather phrase it as "micro-level time violation is the cause"; we're talking about weak parity violation only because that's much more easily measured, and implies time violation. That aside, yes, I would expect a poll of theorists to find at least a sizable minority who think micro-level time violation is the cause of macro-scale time asymmetry.

A great articulation of why people find it hard to adopt a naturalistic worldview

I don't understand what, if anything, you would consider non-arbitrary.

I'm not sure this is actually an important disagreement; I'm ok with dropping it if you want. However, you are the one who suggested that entropy could be calculated in a non-arbitrary way; but I don't think you've offered an example of such a calculation.

And why does that conflict with what anyone says about the "arrow of time"?

It conflicts with the notion that entropy is a good way to consider the problem; entropy is a non-full-information heuristic that doesn't appear in the actual laws of physics.

neither of us is a quantum field theorist

Well, I'm not a theorist, no. I do have a PhD in experimental particle physics. I will admit that the QFT classes tended to fry my brain like an egg, which is one reason I went experimental.

so far as I know no one knows how to do the QFT calculations on anything like the scale required to understand what's happening when you fry an egg

That's true. I do think, however, that an intuitive understanding is sufficient to get a grasp of how a microlevel asymmetry can become macrolevel.

Do you have any actual evidence that it's so?

It seems that such evidence would have to be in the form of simulations or calculations, since you can't very well turn off the weak interaction and see what happens when you fry an egg without it. I am not aware of any such calculation, no. But, again, there's such a thing as a qualitative insight.

A great articulation of why people find it hard to adopt a naturalistic worldview

Yes, a notion of entropy depends on some state of knowledge and observational ability. But that doesn't mean it depends on picking ours in particular, and there are not-so-arbitrary ways to do it.

I don't understand how your suggested calculation is non-arbitrary; you still seem to be picking some criterion and then doing math. My point is that the laws of physics don't do any such thing; they just apply the exact laws of motion to the exact particle locations at every time step. Picking a different criterion for the entropy doesn't help - it's still not going to be what actually happens.

Would you like to make your argument a little more explicit? Do you think that weak parity violation is responsible for the familiar macro-scale time asymmetries everyone notices?

Sorry, I will try to be less brief. The known CP violation occurs, as you point out, in the weak force. (Side note: There is also a large source of CP violation somewhere else in the laws of physics, otherwise we wouldn't observe the matter/antimatter asymmetry we do. But that doesn't change the argument since it must occur at high energies.) When you fry an egg, the interactions are basically electric.

At high energies, the electric and weak force unite into the electroweak force. Now, when you do the quantum-field-theory math encapsulated in Feynman diagrams, you are integrating over all the possible paths from initial to final state; including ones with extremely energetic particles in the intermediate states. (This appears to violate the conservation of energy; the usual explanation given to students is that you can do this because of a Heisenberg uncertainty relation between energy and time. If the time is sufficiently short, "the universe is not aware" that energy conservation was violated. Personally I find this explanation immensely unsatisfying, but I don't understand the underlying math; so I'm taking this on faith. Anyway it's the same phenomenon that causes Hawking radiation around black holes.) Well, with high-energy intermediate states, you can get weak particles in your electric interactions; and then you get time asymmetry. To be sure this is a third-order effect; but then, frying an egg takes several seconds, which is an immense amount of time relative to the characteristic timescale of the weak force. (Which is only 'weak' by comparison to the strong nuclear force.)

A great articulation of why people find it hard to adopt a naturalistic worldview

I keep coming back to entropy because the asymmetry in entropy is one of the things that needs explaining

Again, why bother with entropy as such? Just say "the initial conditions need explaining" and be done.

Given any criterion for distinguishing macrostates, you can (in principle) compute entropy relative to that criterion.

I do not understand how these two paragraphs are a response to what I said. Can you elucidate?

So far as I am aware, there is no reason to think that weak parity violation is responsible for the familiar macro-scale time asymmetries everyone notices.

Electroweak unification. That aside, the original problem was "there is no asymmetry in the laws of physics that can cause [macrolevel asymmetry]; Newton's and Maxwell's (and Einstein's) laws are the same in either time direction". And then we realised that yes, there is an asymmetry in the laws of physics. Well then, that solves the problem; what more do you want, unfried egg in your barley-that-used-to-be-beer?

A great articulation of why people find it hard to adopt a naturalistic worldview

If weak parity violation really explains anything here, I don't see what. Do you have any grounds for suspecting that weak parity violation explains why we see a very dense low-entropy universe in one direction and a very sparse high-entropy universe in the other? Do you have any grounds for suspecting that weak parity violation explains why smashing an egg is easier than putting it together?

So first let me note that the weak parity violations cannot explain the observed matter/antimatter asymmetry; it follows that there is a source of CP violation that we don't know about, and hence also a large T violation.

You keep coming back to entropy, but I think this is the wrong way to look at it. Entropy is a probabilistic framework using multiple states of the same energy, that we apply when we don't have all the information; but the universe does, and is deterministically evolving from one specific state of high density, to another specific state of low density. Humans look at the final state and say "there are a lot of hypothetical states with different specific arrangements, which look a lot like this one; therefore it is high entropy"; but so what? You can't get there from the actual initial conditions; inaccessible states can have no physical effect, and ought to have no philosophical one either. Asking for an explanation of "the evolution from low to high entropy" is meaningless; better to ask for an explanation of where the initial conditions come from.

As for "what does that have to do with frying eggs", I opine that once you have identified a microlevel asymmetry, your work is done; there is no need to go through the tedious steps of finding how it produces a macrolevel asymmetry.

A great articulation of why people find it hard to adopt a naturalistic worldview

Reversed spatial particles look the same to us as unreversed

No they don't; the neutrinos would change their handedness. (So would our amino acids, but that wouldn't affect their functioning, so far as I know, since everything else would as well.) And chiral-reversed neutrinos don't interact with anything. The laws of physics are in fact just about as P-violating as they can possibly be!

and the names "matter" and "anti-matter" are arbitrary

The names are arbitrary, but the functions aren't; matter consists of particles favoured by the CP asymmetry in the laws. Flip everything to antimatter and after a sufficiently long time you have matter again.

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