Wednesday, January 30, 2019

Is some research too politically dangerous?

Gerhard Meisenberg argues:
Some authors have proposed that research on cognitive differences is too dangerous to be allowed to proceed unchecked. ...

1. The alternative to knowledge about human intelligence differences is not ignorance, but false beliefs that people create to explain real-world phenomena.
2. In most cases, true knowledge is more likely than false beliefs to lead to beneficial outcomes.
3. The proper question to ask is not whether intelligence research is dangerous, but whether people in modern societies possess the moral values and intellectual abilities required to make good use of the knowledge.
4. If moral values are found to be lagging behind factual knowledge in modern societies, the appropriate response is not the restriction of “dangerous” knowledge, but the development of moral values capable of putting the knowledge to good use.
You might think that this is obvious, but it is not. The big European Physics center, CERN, has a policy of sponsoring lectures on how women are disadvantaged, and firing anyone who presents data and evidence to the contrary.

Friday, January 25, 2019

Belief in infinite doppelgangers

I mentioned that Brian Greene is sympathetic to many-worlds theory without endorsing it, but he definitely believes in a multiverse that is almost as goofy:
Physicists Brian Greene and Max Tegmark both make variants of the claim that if the universe is infinite and matter is roughly uniformly distributed that there are infinitely many “people with the same appearance, name and memories as you, who play out every possible permutation of your life choices.”
Greene's 2011 book said:
“[I]f the universe is infinite there’s a breathtaking conclusion that has received relatively scant attention. In the far reaches of an infinite cosmos, there’s a galaxy that looks just like the Milky Way, with a solar system that’s the spitting image of ours, with a planet that’s a dead ringer for earth, with a house that’s indistinguishable from yours, inhabited by someone who looks just like you, who is right now reading this very book and imagining you, in a distant galaxy, just reaching the end of this sentence. And there’s not just one such copy. In an infinite universe, there are infinitely many. In some, your doppelgänger is now reading this sentence, along with you. In others, he or she has skipped ahead, or feels in need of a snack and has put the book down. In others still, he or she has, well, a less than felicitous disposition and is someone you’d rather not meet in a dark alley.”
I am not sure which is crazier, this, nonlocality, denial of free will, or many-worlds theory.

When some non-physicists like Deepak Chopra says stuff like this, they get mocked by physicists.

Greene would say that there is someone like in a distant universe, but he regularly blogs in favor of quantum computing instead of against it.

Why do physics professors like Greene and Tegmark get a free pass?

The above paper addresses several problems with the Greene-Tegmark view.

I think the problem is more basic. Once you start talking about infinities like that, you have left the realm of science. You as might as well be talking about angels dancing on the head of a pin.

You might be surprised that a mathematician like myself would be so hostile to infinities. After all, mathematicians use infinities all the time, and know how to deal with all the paradoxes. But the infinities are short-hands for logical arguments that make perfect sense.

What do you do with beliefs that you have no free will, and you have infinitely many copies of yourself in distant universes leading parallel lives? Or that what you think is a personal decision is really splitting yourself from an identical right here in this universe, but invisible? In some of these universes, bizarre things happen, like a tiger giving birth to a goat. But why don't we ever see such nonsense? You can say that those events are unlikely, but there are universes where they happen all the time. How do you know that we are not in one?

I am just scratching the surface of what a nonsensical world view this is.

Historians of science wonder how Galileo and Newton had such coldly rational views towards analyzing the mechanics of simple experiments or celestial observations, and yet they completely accepted all sorts of biblical religious that most scientists today say is just stupid mysticism. How is that possible?

Someday, Greene, Tegmark, and many other leading physicists will be seen similarly. They wrote some good scientific papers, but they also believed in total nonsense that a child could see was ridiculous.

Here are some mathematicians talking about infinities, from a recent podcast:
Dr. Garibaldi decided to talk about a theorem he calls the unknowability of irrational numbers. Many math enthusiasts are familiar with the idea of countable versus uncountable infinities. ...

The set of all real numbers—all points on the number line—is uncountable, as Georg Cantor proved using a beautiful argument called diagonalization. The basic idea is that any list of real numbers will be incomplete: if someone tells you they’ve listed the real numbers, you can cook up a number their list omits. ...

The end result is, in Dr. Garibaldi’s words, sort of hideous. Any classes of numbers you can describe explicitly end up being merely countably infinite. Even with heaping helpings of logarithms, trigonometry, and gumption, the number line is more unknown than known.
So all the real numbers we know anything about are countable. All our knowledge is countable. The reals are uncountable, so almost all real numbers are unknowable in some sense.

Mathematicians all understand this, and it is important in some mathematical arguments, but it doesn't really have any grand philosophical implications. Knowledge is countable because of they way knowledge is defined and accepted. Actual things are finite.

You could say that there is some real number that perfectly encodes your doppelganger, or records all your memories, or predicts all your future behavior, or any other weirdo fantasy you have. We cannot construct that real number, or say anything interesting about it.

You can fantasize all you want about alternate realities, but the physics and the math don't really add anything.

Wednesday, January 23, 2019

No need for new collider

Bee Hossenfelder writes:
Since the late 1960s, when physicists hit on the “particle zoo” at nuclear energies, they always had a good reason to build a larger collider. That’s because their theories of elementary matter were incomplete. But now, with the Higgs-boson found in 2012, their theory – the “standard model of particle physics” – is complete. It’s done. There’s nothing missing. All Pokemon caught.

The Higgs was the last good prediction that particle physicists had. This prediction dates back to the 1960s and it was based on sound mathematics. In contrast to this, the current predictions for new particles at a larger collider – eg supersymmetric partner particles or dark matter particles – are not based on sound mathematics. These predictions are based on what is called an “argument from naturalness” and those arguments are little more than wishful thinking dressed in equations. ...

This situation is unprecedented in particle physics. The only reliable prediction we currently have for physics beyond the standard model is that we should eventually see effects of quantum gravity. But for that we would have to reach energies 13 orders of magnitude higher than what even the next collider would deliver. It’s way out of reach.
I agree with this. Bee is going to be an outcast, because high-energy physicists are not going to like someone throwing cold water on their $10B funding proposals.

If money were budgeted for a new collider and then canceled, would the money be spent on anything better? Maybe not.

I like Physics, and I like money being spent on it. But physicists need to tell the truth about what they are doing. A bigger new collider is unlikely to tell us much.

Update: Bee also has an op-ed in the NY Times:
I used to be a particle physicist. ...

The stories about new particles, dark matter and additional dimensions were repeated in countless media outlets from before the launch of the L.H.C. until a few years ago. What happened to those predictions? The simple answer is this: Those predictions were wrong — that much is now clear. ...

To date, particle physicists have no reliable prediction that there should be anything new to find until about 15 orders of magnitude above the currently accessible energies. And the only reliable prediction they had for the L.H.C. was that of the Higgs boson. Unfortunately, particle physicists have not been very forthcoming with this information.

Monday, January 21, 2019

The Black Hole Singularity

Einstein famously did not believe in black holes, because a black hole has a singularity, and singularities do not occur in nature.

But which black hole singularity?

A black hole actually has two singularities, one at the center and one at the event horizon. Both singularities show up in common parameterizations of the Schwarzschild solution. Each could have been troublesome for Einstein.

The singularity at the center is based on the idea that all the mass collapses to a single point, so that the point geometrically blows up to something of infinite diameter. Physically, the idea is that if the mass is sufficiently concentrated, the gravity force will overwhelm all other forces, including the Pauli exclusion force. Then nothing can stop all the mass disappearing into the hole in spacetime.

Wikipedia says:
The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was during the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars in the late 1960s sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
I don't get this. What did they think that a black hole was, before 1958?

This singularity is indeed a troublesome concept, but it is not clear that it has any physical significance. We don't know that gravity will really overwhelm all other forces. That belief is based on an extrapolation that can never be tested. Nothing inside the black hole can have any causal effect on anything outside the black hole.

The other singularity is at the event horizon. This was not well understood until decades after Schwarzschild. Now it is common for textbook to say that it is a removable singularity, or maybe not a real singularity, because someone falling into the black hole may not notice anything strange at the event horizon. I say "may not", because some argue that someone would see a firewall.

The event horizon does appear to be a singularity in some coordinate systems, and therefore to some observers. Someone watching the black hole might think it very strange that a falling object seems to take an infinite amount of time to cross the event horizon. That infinity is a singularity.

You don't really need to believe in singularities to study black hole physics. The singularities are not observable.

Friday, January 18, 2019

Psychiatrist blogger tries Kuhnian paradigms

Slate Star Codex is a very popular anonymous psychiatrist blog, and he takes a deep dive:
When I hear scientists talk about Thomas Kuhn, he sounds very reasonable. Scientists have theories that guide their work. Sometimes they run into things their theories can’t explain. Then some genius develops a new theory, and scientists are guided by that one. So the cycle repeats, knowledge gained with every step.

When I hear philosophers talk about Thomas Kuhn, he sounds like a madman. There is no such thing as ground-level truth! Only theory! No objective sense-data! Only theory! No basis for accepting or rejecting any theory over any other! Only theory! No scientists! Only theories, wearing lab coats and fake beards, hoping nobody will notice the charade!

I decided to read Kuhn’s The Structure Of Scientific Revolutions in order to understand this better. Having finished, I have come to a conclusion: yup, I can see why this book causes so much confusion. ...

But one of my big complaints about this book is that, for a purported description of How Science Everywhere Is Always Practiced, it really just gives five examples. Ptolemy/Copernicus on astronomy. Alchemy/Dalton on chemistry. Phlogiston/Lavoisier on combustion. Aristotle/Galileo/Newton/Einstein on motion. And ???/Franklin/Coulomb on electricity.

It doesn’t explain any of the examples. If you don’t already know what Coulomb’s contribution to electricity is and what previous ideas he overturned, you’re out of luck. And don’t try looking it up in a book either. Kuhn says that all the books have been written by people so engrossed in the current paradigm that they unconsciously jam past scientists into it, removing all evidence of paradigm shift. This made parts of the book a little beyond my level, since my knowledge of Coulomb begins and ends with “one amp times one second”.

Even saying Kuhn has five examples is giving him too much credit. He usually brings in one of his five per point he’s trying to make, meaning that you never get a really full view of how any of the five examples exactly fit into his system.

And all five examples are from physics. Kuhn says at the beginning that he wished he had time to talk about how his system fits biology, but he doesn’t. He’s unsure whether any of the social sciences are sciences at all, and nothing else even gets mentioned.
Kuhn is popular becaues he allows philosophers, social scientists, and crackpot to deny truth, and to complain that their ideas are just being ignored because they do not fit the paradigm.

SSC is right that Kuhn's points are only about poorly reasoned interpretations of centuries-old physics. Kuhn does not attempt to apply his silly paradigm theory to XX century science at all.

Even tho Kuhn wrote a whole book on quantum mechanics, he could never figure out whether it was a paradigm shift, because the supposed revolution did not match his theory about scientific revolutions.

Kuhn's best example is Ptolemy/Copernicus, but that was 500 years ago, and even that is very misleading.

SSC is right that the scientists who say Kuhn is reasonable will explain by saying something like "knowledge gained with every step." But Kuhn did not really see science that way. Switching from Ptolemy to Copernicus was not an increase in knowledge, he would say, but just a different point of view.

Scientists like to think that they are part of a vast program to establish facts and develop theories that converge on truth. Kuhn firmly rejected that view.

Kuhn has fallen somewhat out of favor among philosophers today, but only because they have moved on to even nuttier ideas of science.

Wednesday, January 16, 2019

Atomic laws are not deterministic

Evolutionist Jerry Coyne is on a free will rant again:
[Scott] Aaronson thinks there’s a real and important question in the free-will debates, but argues that that question is not whether physical determinism of our thoughts and actions be true, but whether they are predictable. ...

What I meant was “physical determinism” in the sense of “our behavior obeys the laws of physics”, not that it is always PREDICTABLY determined in advance. ...

As he says at 4:15, “My view is that I don’t care about determinism if it can’t be cashed out into actual predictability.”

This seems to me misguided, conflating predictability with the question of determinism. ...

What I care about is whether determinism be true. And I think it is, though of course I can’t prove it. All I can say is that the laws of physics don’t ever seem to be violated, and, as Sean Carroll emphasizes, the physics of everyday life is completely known. ...

What I meant was “physical determinism” in the sense of “our behavior obeys the laws of physics”, not that it is always PREDICTABLY determined in advance. ...

I’m doing my best to explain what seems obvious to me: we are material creatures made of atoms; our behaviors and actions stem from the arrangement of those atoms in our brains, and those atoms must obey the laws of physics. Therefore, our behaviors and actions must obey the laws of physics, and are “deterministic” in that sense. We are, in effect, robots made of meat, with a really sophisticated onboard guidance system. I know many people don’t like that notion, but I think that, given the laws of physics, it’s ineluctable.
I have to side with Aaronson here, and wonder what Coyne even means by "the laws of physics".

Of course the laws of physics are not violated. If they were, then they would not be laws of physics. Saying that does not tell us anything about free will.

Saying that we are made of atoms that obey the laws of physics is an odd argument for determinism. Our best theories about atoms are not deterministic.

Carroll has his own problems, as he believes in many-worlds.

Monday, January 14, 2019

IBM announces quantum computer

ExtremeTech reports:
At CES 2019, IBM Research has made what it hopes is a big step in that direction with what it calls the “first fully-integrated commercial quantum computer,” the Q System One. ...

IBM will be adding the Q System One to its arsenal of cloud-accessible quantum computers, first at its existing quantum data center, and at a new one planned for Poughkeepsie, New York. So for those who aren’t Fortune 500 companies with a budget to purchase their own (IBM hasn’t announced a price for the unit, but if you have to ask…), they’ll be able to make use of one. The current version reportedly “only” supports 20 Qubits, so the breakthrough isn’t in processing power compared with other research models, but instead in reliability and industrial design suitable for use in commercial environments.
This computer will be outperformed by your cell phone.

If the computer could actually do anything useful or have any performance advantage, you can be sure that IBM would be bragging about it. If they could achieve quantum supremacy, there would be academic papers and lobbying for a Nobel Prize.

Friday, January 11, 2019

Brian Greene still plugging string theory

Sam Harris interviews Brian Greene in this two-hour video.

Greene is indignant when Harris says that string theory has failed to deliver the goods. Greene says that the theory has made great progress, and has merged gravity and quantum mechanics. The only trouble is that we do not know what that merged theory is, and it has made any testable predictions. That is not much of a criticism, he says, because no quantum gravity theory will ever make any testable predictions.

Someone asked about Bohr saying that physics is about observables. Greene prefers a wider view, and says that physics should look behind the curtain and tell us what is really going on.

So Greene can justify a string theory with no testable predictions.

Greene also defended many-worlds theory and Bohmian mechanics, altho he has not fully adopted them because the measurement problem is unsolved.

Harris points out that Bohmian mechanics is nonlocal, so doing something in one place can have an instantaneous distant effect. Greene agreed, but said that quantum mechanics is nonlocal anyway.

Greene is very misleading here. It is true that in textbook QM, if you make a measurement and collapse the wavefunction, then your knowledge of some distant particle can be immediately affected. You can say that is nonlocal, but classical mechanics is nonlocal in the same way. Bohmian mechanics is different in that it says that an electron is in one place, but its physical effects are in another place. That is a fatal flaw, since no such nonlocality has ever been observed in nature.

And any defense of many-worlds is nutty.

He gives this argument, common among many-worlds advocates, that it is a simpler theory, and thus preferable under Occam's Razor. He gives an example. Suppose a simple quantum experiments results in an electron being in one of two places, symbolized by his left hand and right hand. Suppose you then find the electron in his left hand. Under Copenhagen, you would deduce that the electron is not in his right hand. But that deduction is an extra step, and the many-worlds theory is more parsimonious because it skips that step and posits that the electron is in his right hand in a parallel universe.

It is amazing to see an educated man make such a silly argument with a straight face. The argument really doesn't even have much to do with quantum mechanics, as you could use it with any theory that makes predictions, and concoct a many-worlds variant of the theory that does not make any predictions.

Besides many-worlds, Greene defends physical theories in which anything can happen. If you assume infinite space, infinite time, infinite universes, etc., then pretty much anything you can imagine would be happening somewhere, and happening infinitely many times. In particular, Jesus rose from the dead.

Greene agrees with Harris that humans have no free will. Greene rejects Harris's determinism, but says that the laws of physics have no room for free will.

At least Greene did not go along with Harris's wacky consequentialist vegetarian philosophy.

It is too bad that Physics does not have better spokesmen.

Wednesday, January 9, 2019

Paper argues QM is about determinables

I posted on the characteristic trait of quantum mechanics. Now David Albert wrote a paper with his own novel view:
I distinguish between two conceptually different kinds of physical space: a space of ordinary material bodies, which is the space of points at which I could imaginably place (say) the tip of my finger, or the center of a billiard-ball, and a space of elementary physical determinables, which is the smallest space of points such that stipulating what is happening at each one of those points, at every time, amounts to an exhaustive physical history of the universe. In all classical physical theories, these two spaces happen to coincide – and what we mean by calling a theory “classical”, and all we mean by calling a theory “classical”, is (I will argue) precisely that these two spaces coincide. But once the distinction between these two spaces in on the table, it becomes clear that there is no logical or conceptual reason why they must coincide – and it turns out (and this is the main topic of the present paper) that a very simple way of pulling them apart from one another gives us quantum mechanics.
He presents this as how to teach quantum mechanics, as he says it is the essence of the quantum mysteries.

To explain his artificial examples, he has to use non-local Hamiltonians, and refer to kooky interpretations like many-worlds and Bohmian pilot waves. His whole idea of determinables is based on thinking of particles as existing as points in space.

I don't think his approach helps to understand quantum mechanics at all. I am just posting this as another opinion of how quantum mechanics differs from classical mechanics.

Monday, January 7, 2019

The characteristic trait of quantum mechanics

Erwin Schroedinger introduced the term "entanglement" with this 1935 paper:
1. When two systems, of which we know the states by their respective representatives, enter into temporary physical interaction due to known forces between them, and when after a time of mutual influence the systems separate again, then they can no longer be described in the same way as before, viz. by endowing each of them with a representative of its own. I would not call that one but rather the characteristic trait of quantum mechanics, the one that enforces its entire departure from classical lines of thought. By the interaction the two representatives (or ψ-functions) have become entangled. To disentangle them we must gather further information by experiment, although we knew as much as anybody could possibly know about all that happened.
This is an important insight, but I don't agree that this is really "the characteristic trait of quantum mechanics.

How is it that quantum mechanics allows creating systems where we could know "as much as anybody could possibly know", and still leave some questions unanswered?

In order for entanglement to seem so mysterious, it has to be combined with some other quantum mystery.

I have argued here that the the characteristic trait of quantum mechanics is the non-commuting observables.

Sure enough, Schroedinger’s argument in the next few pages depends on non-commuting observables. That is where the quantum weirdness is. It is not so weird that our knowledge of a system could depend on a system with which it previously interacted.

Thursday, January 3, 2019

The Mind Body Problems

SciAm writer John Horgan is plugging his latest book, Mind-Body Problems: Science, Subjectivity and Who We Really Are. You can read it online for free.

It does not actually solve the mind-body problem, but rather tells you about an assortment of characters who are trying.

Check out his website, or an EconTalk interview of him.

Machines appear deterministic (until chaos, at least), while human minds do not. If you believe in the reductionist scientific program, then it should be possible to look at smaller and smaller scales until determinism disappears.

That is exactly what we see, of course. Mechanistic determinism disappears at the atomic level.

When you point this out to anti-free-will advocates, they say you are looking at randomness, not free will. You are supposed to recognize it as random because you cannot predict it.

Isn't that how you are supposed to recognize free will? The hallmark of free will is that someone else cannot predict the action.

One of Horgan's arguments is that the existence of free will is implied by the observation that some people have more of it than others. Okay, I accept that. But then he cites babies as having not very much free will.

No, I think toddlers have more free will than adults. Maybe not newborn babies, but by age 1.5, they make dozens of decisions a day, completely autonomously.

Horgan's main argument is that free will is essential for his entire outlook on life. He has figured out how to dispense with God and religion, but not free will.

Sabine Hossenfelder rips into one of the ideas that Horgan is pursuing:
I recently discovered panpsychism. That’s the idea that all matter – animate or inanimate – is conscious, we just happen to be somewhat more conscious than carrots. Panpsychism is the modern elan vital.

The particles in the standard model are classified by their properties, which are collectively called “quantum numbers.” The electron, for example, has an electric charge of -1 and it can have a spin of +1/2 or -1/2. ...

Now, if you want a particle to be conscious, your minimum expectation should be that the particle can change. It’s hard to have an inner life with only one thought. But if electrons could have thoughts, we’d long have seen this in particle collisions because it would change the number of particles produced in collisions.

In other words, electrons aren’t conscious, and neither are any other particles. It’s incompatible with data.
A comment relates this to an ancient argument:
I think it's interesting to relate it to Galen's argument against atomism. He claimed that (i) atoms cannot be conscious, since they are unchanging, (ii) no combination of unconscious parts can be conscious, (iii) we are conscious. Therefore, we cannot be combinations of atoms.
This issue drew a surprisingly large number of comments, with some defending panpsychism.

Some view consciousness and free will as mere illusions. I think that view degenerates into life being meaningless, but some intelligent folks say it anyway.

If you believe in consciousness and free will, it seems plausible to me that the quantum mechanics of electrons and other particles could play an essential role. Otherwise, consciousness and free will would have to arise in classical deterministic machines, and that is even harder to imagine. I think that Bee has fallen for a version of Galen's fallacy.

Update: Lubos Motl sides with panpsychism. His argument is that if there is human consciousness, and if we are all made of atoms, then those atoms must have tiny bits of whatever consciousness is.