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Friday, August 30, 2019

Einstein did not get relativity from Hume

An Aeon essay starts:
In 1915, Albert Einstein wrote a letter to the philosopher and physicist Moritz Schlick, who had recently composed an article on the theory of relativity. Einstein praised it: ‘From the philosophical perspective, nothing nearly as clear seems to have been written on the topic.’ Then he went on to express his intellectual debt to ‘Hume, whose Treatise of Human Nature I had studied avidly and with admiration shortly before discovering the theory of relativity. It is very possible that without these philosophical studies I would not have arrived at the solution.’

More than 30 years later, his opinion hadn’t changed, as he recounted in a letter to his friend, the engineer Michele Besso: ‘In so far as I can be aware, the immediate influence of D Hume on me was greater. I read him with Konrad Habicht and Solovine in Bern.’ We know that Einstein studied Hume’s Treatise (1738-40) in a reading circle with the mathematician Conrad Habicht and the philosophy student Maurice Solovine around 1902-03. This was in the process of devising the special theory of relativity, which Einstein eventually published in 1905. It is not clear, however, what it was in Hume’s philosophy that Einstein found useful to his physics.
It is amazing that anyone takes Einstein's egomania seriously.

Einstein got relativity from Lorentz and Poincare, and spent his whole life lying about it. Saying that he got his ideas from some philosopher is just a way of denying credit to Lorentz and Poincare.

Sunday, August 25, 2019

Worrying about testing the simulation hypothesis

Philosophy professor Preston Greene argues in the NY Times:
ut what if computers one day were to become so powerful, and these simulations so sophisticated, that each simulated “person” in the computer code were as complicated an individual as you or me, to such a degree that these people believed they were actually alive? And what if this has already happened?

In 2003, the philosopher Nick Bostrom made an ingenious argument that we might be living in a computer simulation created by a more advanced civilization. He argued that if you believe that our civilization will one day run many sophisticated simulations concerning its ancestors, then you should believe that we’re probably in an ancestor simulation right now. ...

In recent years, scientists have become interested in testing the theory. ...

o far, none of these experiments has been conducted, and I hope they never will be. Indeed, I am writing to warn that conducting these experiments could be a catastrophically bad idea — one that could cause the annihilation of our universe. ...

if our universe has been created by an advanced civilization for research purposes, then it is reasonable to assume that it is crucial to the researchers that we don’t find out that we’re in a simulation. If we were to prove that we live inside a simulation, this could cause our creators to terminate the simulation — to destroy our world. ...

As far as I am aware, no physicist proposing simulation experiments has considered the potential hazards of this work.
Isn't it great that we have philosophers to worry about stuff like this?

Extending this reasoning further, we should shut down the LHC particle collider, and all the quantum computer research. These are exceptionally difficult (ie, computationally intensive) to simulate. If we overwhelm the demands on the simulator, then the system could crash or get shut down.

We probably should not look for extraterrestrials either.

A psychiatrist wonders about our simulator overlords reading NY Times stories worrying about simulation.

I think these guys are serious, but I can't be sure. It is not any wackier than Many-Worlds.

Another philosopher, Richard Dawid, has a new paper on the philosophy of string theory:
String theory is a very different kind of conceptual scheme than any earlier physical theory. It is the first serious contender for a universal final theory. It is a theory for which previous expectations regarding the time horizon for completion are entirely inapplicable. It is a theory that generates a high degree of trust among its exponents for reasons that remain, at the present stage, entirely decoupled from empirical confirmation. Conceptually, the theory provides substantially new perspectives ...
Wow, a "universal final theory" that is entirely "decoupled" from experiment, and with no hope of "completion" in the foreseeable future. But it is conceptually interesting!

I am sure Dawid thinks that he is doing string theorists a favor by justifying their work, but he has to admit that the theory has no merit in any sense that anyone has ever recognized before.

Thursday, August 22, 2019

Quantum physics is not in crisis

The latest Lumo rant starts:
Critics of quantum mechanics are wrong about everything that is related to foundations of physics and quite often, they please their readers with the following:

Physics has been in a crisis since 1927. ...
You may see that they 1) resemble fanatical religious believers or their postmodern, climate alarmist imitators or the typical propaganda tricksters in totalitarian regimes. They tell you that there is a crisis so you should throw away the last pieces of your brain and behave as a madman – that will surely help. ...

In reality, the years 1925-1927 brought vastly more true, vastly more solid, vastly more elegant, and vastly more accurate foundations to physics, foundations that are perfectly consistent and that produce valid predictions whose relative accuracy may be \(10^{-15}\) (magnetic moment of the electron).

On the new postulates of quantum mechanics, people have built atomic and molecular physics, quantum chemistry, modern optics, lasers, condensed matter physics, superconductors, semiconductors, graphene and lots of new materials, transistors, diodes of many kind, LED and OLED and QLED panels, giant magnetoresistance, ...
He is attacking Sean M. Carroll's book, and other similar modern gripes about quantum mechanics.

I mostly agree with him. Quantum mechanics is the most successful theory we have, and we have professors saying it is in crisis, or it doesn't make sense, or the foundations are wrong, or some such nonsense.

If quantum mechanics does not obey your idea of what a theory should be, then it is time to re-examine your prejudices about what a theory should be. Quantum mechanics has succeeded beyond all expectations in every possible way.

Dr. Bee says:
Now, it seems that black holes can entirely vanish [over trillions of years] by emitting this radiation. Problem is, the radiation itself is entirely random and does not carry any information. So when a black hole is entirely gone and all you have left is the radiation, you do not know what formed the black hole. Such a process is fundamentally irreversible and therefore incompatible with quantum theory. It just does not fit together.
I am baffled how obviously intelligent physicists can say this nonsense. Everything in quantum mechanics is irreversible. I don't even know any reversible quantum experiments.

Quantum computers are supposed to do reversible operations on qubits, but they have never gotten it to work for more than a few microseconds, as far as I know. And Bee is worried that a trillion-year black hole decay might be irreversible? This is craziness.

Thierry Batard argues in a new paper:
In glaring contrast to its indisputable century-old experimental success, the ultimate objects and meaning of quantum physics remain a matter of vigorous debate among physicists and philosophers of science. ...

In the eyes of the Fields medalist RenĂ© Thom (2016), this makes quantum physics “… far and away the intellectual scandal…” of the twentieth century. ...

quantum physics has “… been accused of being unreasonable and unacceptable, even inconsistent, by world-class physicists (for example, Newman…)” (Rovelli 1996)
How can something work flawlessly and be so unacceptable?

This is a bit like someone going around telling everyone that cell phones cannot possibly work. What are you going to believe -- your own eyes or some philosophical professor?

Wednesday, August 21, 2019

Carroll writes new book on Many Worlds

Peter Woit asks What’s the difference between Copenhagen and Everett?
What strikes me when thinking about these two supposedly very different points of view on quantum mechanics is that I’m having trouble seeing why they are actually any different at all.
To the extent that they are just interpretations, there is no substantive difference. With disputes about the definitions, this is not so clear.

Here are a couple of the better comments:
They difference is in the part that you don’t want to discuss, which is that Everettians postulate the other worlds are real, while Copenhagenists refuses to say anything about what cannot be observed.

Good old books inform that the same issue had been fiercely debated around 1926, when Schroedinger/Einstein wanted to describe everything via a deterministic local equation, getting rid of quantum jumps. Heisenberg/Bohr explained that it’s not possible because we see particles as events. Decoherence and all modern stuff allow to understand better but don’t change the key point: we need probabilities. So the Schroedinger equation is just a tool for computing probabilities in configuration space.
Woit goes on to review Sean M. Carroll's new book, which is a 368-page argument for the Many World Theory of quantum behavior.

Woit says Carroll is a good writer and explainer, but the Many Worlds stuff is the babbling of a crackpot. They theory is so silly it is hard to take anyone seriously who pushes Many Worlds.

Thursday, August 15, 2019

The Quantum Computing Party may never start

SciAm reports:
The Quantum Computing Party Hasn’t Even Started Yet

But your company may already be too late ...

For example, at IonQ, the company I co-founded to build quantum computer hardware, we used our first-generation machine to simulate a key measure of the energy of a water molecule. Why get excited when ordinary computers can handle the same calculation without breaking a sweat? ...

If you pay even a little attention to technology news, you've undoubtedly heard about the amazing potential of quantum computers, which exploit the unusual physics of the smallest particles in the universe. While many have heard the buzz surrounding quantum computing, most don't understand that you can't actually buy a quantum computer today, and the ones that do exist can't yet do more than your average laptop. ...

It will take a few more years of engineering for us to build capacity in the hundreds of qubits, but I am confident we will, and that those computers will deliver on the amazing potential of quantum technology.

The choice facing technology leaders in many industries is whether to start working today on the quantum software that will use the next generation of computers or whether to wait and watch the breakthroughs be made by more agile competitors.
Or wait to watch all the quantum computer companies fail.

He is right that you cannot buy a quantum computer, and the research models are so primitive as to be useless.

The party may never start.

Tuesday, August 13, 2019

Quantum Cryptography is still useless

IEEE Spectrum reports:
Quantum Cryptography Needs a Reboot

Quantum technologies—including quantum computing, ultra-sensitive quantum detectors, and quantum random number generators—are at the vanguard of many engineering fields today. Yet one of the earliest quantum applications, which dates back to the 1980s, still appears very far indeed from any kind of widespread, commercial rollout.

Despite decades of research, there’s no viable roadmap for how to scale quantum cryptography to secure real-world data and communications for the masses.

That’s not to say that quantum cryptography lacks commercial applications. ...

From a practical standpoint, then, it doesn’t appear that quantum cryptography will be anything more than a physically elaborate and costly—and, for many applications, largely ignorable—method of securely delivering cryptographic keys anytime soon.
So it does lack commercial applications. The technology does not do anything useful, as I have explained here many times.
“The same technologies that will allow you to do [quantum crypto] will also allow you to build networked quantum computers,” Bassett says. “Or allow you to have modular quantum computers that have different small quantum processors that all talk to each other. The way they talk to each other is through a quantum network, and that uses the same hardware that a quantum cryptography system would use.”

So ironically, the innards of quantum “cryptography” may one day help string smaller quantum computers together to make the kind of large-scale quantum information processor that could defeat… you guessed it… classical cryptography.
So all these folks think that classical cryptography is doomed. Someone will first have to invent a quantum processor, because we can try to network such processors.

Friday, August 9, 2019

$3M prize for dead-end physics idea

Dr. Bee reports:
The Breakthrough Prize is an initiative founded by billionaire Yuri Milner, now funded by a group of rich people which includes, next to Milner himself, Sergey Brin, Anne Wojcicki, and Mark Zuckerberg. The Prize is awarded in three different categories, Mathematics, Fundamental Physics, and Life Sciences. Today, a Special Breakthrough Prize in Fundamental Physics has been awarded to Sergio Ferrara, Dan Freedman, and Peter van Nieuwenhuizen for the invention of supergravity in 1976. The Prize of 3 million US$ will be split among the winners.
What you never heard of this work? That is because it was a dead-end, and never led to anything.

For a couple of years in the 1970s, supersymmetry gravity was an exciting idea, because it was thought that it would make quantum gravity renormalizable. However that turned out to be false, and the theory is worthless.

Like string theory, it has no connection to any observational science. But even work, it doesn't even make sense as a physical theory.

Update: Lumo writes:
Nature, Prospect Magazine, and Physics World wrote something completely different. The relevant pages of these media have been hijacked by vitriolic, one-dimensional, repetitive, scientifically clueless, deceitful, and self-serving anti-science activists and they tried to sling as much mud on theoretical physics as possible – which seems to be the primary job description of many of these writers and the society seems to enthusiastically fund this harmful parasitism.
Check them yourself. The Nature article says:
A lack of evidence should also not detract from supergravity’s achievements, argues Strominger, because the theory has already been used to solve mysteries about gravity. For instance, general relativity apparently allows particles to have negative masses and energies, in theory.
No, that is a big lie. Supergravity has nothing to do with positive mass. For details, see the comments on Woit's blog. Briefly, Witten published an outline for a proposed spinor proof of the Schoen-Yau positive mass theorem, and the paper ended with a short section starting with "a few speculative remarks will be made about the not altogether clear relation between the previous argument and supergravity." That's all.

Friday, August 2, 2019

Science journals must be politically correct

Indian-born British writer Angela Saini has found the formula, with articles in Scientific American:
The “race realists,” as they call themselves online, join the growing ranks of climate change deniers, anti-vaxxers and flat-earthers in insisting that science is under the yoke of some grand master plan designed to pull the wool over everyone’s eyes. In their case, a left-wing plot to promote racial equality when, as far as they’re concerned, racial equality is impossible for biological reasons. ...

Populism, ethnic nationalism and neo-Nazism are on the rise worldwide. If we are to prevent the mistakes of the past from happening again, we need to be more vigilant.
And Nature:
Racist ‘science’ must be seen for what it is: a way of rationalizing long-standing prejudices, to prop up a particular vision of society as racists would like it to be. It is about power. ... A world in thrall to far-right politics and ethnic nationalism demands vigilance. We must guard science against abuse and reinforce the essential unity of the human species.
She argues that there is no such thing as human races, and that genetics has nothing to do with the observed differences in athletic performance.

She is from India, which is not really competitive in the sports the rest of the world. So perhaps she does not realize how obvious the biological differences in sports are. But what excuse does Nature and SciAm for publishing her nonsense?

If these journals can lie to us about human races, then they can also lie about climate change and a lot of other subjects.