Sunday, December 16, 2018

How to stop Copenhagen collapses

A philosophy of science article says:
In the science fiction novel Quarantine, Greg Egan imagines a universe where interactions with human observers collapse quantum wavefunctions. Aliens, unable to collapse wavefunctions, tire of being slaughtered by these collapses. In response they erect an impenetrable shield around the solar system, protecting the rest of the universe from human interference and locking humanity into a starless Bubble.
This is funny. This would be the logical conclusion of some explanations of the Copenhagen interpretation.

With no humans to make observations, space aliens might happily live in Schroedinger cat states, where they are half-alive and half-dead.

This sort of thought experiment drives a lot of cosmologists to reject Copenhagen, and believe in many-worlds or some other nonsense.

Another web paper says:
In popular articles about quantum computing it’s common to describe qubits as having the ability to “be in both |0>|0> and |1>|1> states at once”, and to say things like “quantum computers get their power because they can simultaneously be in exponentially many quantum states!”

I must confess, I don’t understand what such articles are talking about.
Those explanations are common because of that stupid Schroedinger cat story, so bits can be on and off at the same time.

Scott Aaronson is a believer in quantum computing, but he often explains that it is a false myth that quantum computers get their power from qubits being in two states at the same time.

So where do quantum computers get their alleged power? That is never convincingly explained. Aaronson has tried many times, and I think that he is writing another book on the subject. Sometimes he says it is from negative probabilities or some other obscure quantum technicality. He has never been able to get his point across to science journalists, so he has quit talking to them.

Friday, December 14, 2018

Deriving the constancy of light speed

Lots of theoretical physicists, such as string theorists, try to derive physical laws from first principles, instead of relying on observation or experiment.

When has this ever worked?

Some people think that Einstein created special relativity this way. That is completely false, and special relativity was developed directly from experiment.

Nevertheless, it seems possible that special relativity could have been derived from first principles. Here is a recent paper that gives such a derivation:
An exposition of special relativity without appeal to "constancy of speed of light" hypotheses

We present the theory of special relativity here through the lens of differential geometry. In particular, we explicitly avoid any reference to hypotheses of the form "The laws of physics take the same form in all inertial reference frames" and "The speed of light is constant in all inertial reference frames", or to any other electrodynamic phenomenon. For the author, the clearest understanding of relativity comes about when developing the theory out of just the primitive concept of time (which is also a concept inherent in any standard exposition) and the basic tenets of differential geometry.
I have made similar arguments on this blog, as well as taking it further to electromagnetism and the standard model of particles.

Thursday, December 13, 2018

SciAm joins the attack on Black patriarchy

Fifty years ago, Scientific American was the best general-interest science magazine in the world. It is still good, but has gone downhill, both in promoting schlock science and adhering to leftist politics. Eg, see this ridiculous article saying that the USA needs DACA privileges for illegal aliens in order to do science research.

I mentioned MeToo allegations against a prominent science popularizer, and now SciAm piles on:
But my own experience—backed by data—teaches me that Black patriarchy is real and the harm specifically to Black women is significant. In this case, the harm is multidimensional ...

It’s true that some details of these allegations have yet to be corroborated, ... But in my view, I believe the claims are credible, which means he directly harmed multiple women, most egregiously by allegedly raping a member of his own already marginalized community.
She says this in spite of the fact that she knows the guy personally, and has never seen him do anything inappropriate. She and SciAm explain the uppercase Black:
I have chosen to capitalize the word “Black” and lowercase “white” throughout this book. I believe “Black” constitutes a group, an ethnicity equivalent to African-American, Negro, or, in terms of a sense of ethnic cohesion, Irish, Polish, or Chinese. I don’t believe that whiteness merits the same treatment. Most American whites think of themselves as Italian-American or Jewish or otherwise relating to other past connections that Blacks cannot make because of the familial and national disruptions of slavery. So to me, because Black speaks to an unknown familial/national past it deserves capitalization.
No, this is so stupid and illogical that it is embarrassing to see it on SciAm.com. I had no idea that some editors believe that Whites are not worthy of an uppercase W. I think that I will start capitalizing the word.

Saying "multiple women" makes it sound as if there are similar or corroborrating allegations, but there are not. One involved a women who was showing off a shoulder tattoo while taking a selfie with him at a party, and he looked to see if the tattoo included Pluto. He would have been rude not to look for Pluto, considering he wrote a book on whether Pluto is a planet.

Saying "claims are credible", just means that someone told a story about events 30 years ago that could have happened. There is no evidence other than someone telling a story 30 years after the fact. From that she leaps to saying that this means that he raped a black girl as part of the "Black patriarchy".

This looks like libel to me, but there is no practical legal remedy. I would rather not even mention his name.

Here is more politicized science, from Scott Aaronson:
Michael Says: I’m surprised you didn’t mention the big one- where can we find evidence that Donald Trump conspired with the Russians?

Scott Says: Michael #26: Again, not worth wasting a question on. Facts in the public record made it obvious since even before the election that they did collude, modulo uninteresting hairsplitting about the meaning of “collude.” Like, Trump openly urged the Russians to hack the emails. In the norms that used to apply, in the world that made minimal sense, that would already count as collusion and prevent him from being president (along with ~500 other violations of basic democratic norms). I’d rather ask the NP-genie: what can we do or say to get back to that world?
No, Trump did not openly urge the Russians to hack the emails. Even if he did, anything done in the open is not a conspiracy. And there is no law against a presidential candidate colluding with the Russians to seek support.

SciAm columnists and Aaronson are entitled to their political opinions, of course, but we have a scientific and academic establishment that is overwhelmingly leftist, and extraordiarily gullible in believing claims that support their leftist politics. I do not trust them when they give opinions on global warming or quantum computing.

Wednesday, December 12, 2018

How the apple inspired Newton

A physics blogger writes:
As someone whose job it is to help people understand and appreciate physics, I absolutely hate the way most people talk about Isaac Newton and how he developed his theory of gravity. It's not the apple bit that I have a problem with; that's an important part of the story, and even historically accurate!
Accurate?

I always assumed that Isaac Newton's big insight upon seeing the apple fall was that the Moon was falling from the same gravity.

This article says that there is evidence that Newton really was inspired by an apple, but his big insight was that the Earth was pulling on the apple in the same way that the apple was pulling on the Earth. The Earth also falls toward the apple, ever so slightly.
We can thank this little touch of plague for virtually all of Newton's scientific legacy: in that single impromptu gap year, he had his epiphany about gravity, discovered that white light is made up of all the colors in the spectrum, and basically invented calculus.
The problem with that story is that Newton got involved in nasty priority fights over ideas that he failed to publish until many years later. So he could be exaggerating how much he figured out in that year.

Monday, December 10, 2018

Deutsch says single universe is stone dead

Quanta mag has an article about a recent paper on how the Wigner's friend paradox should unfluence interpretations of quantum mechanics:
Now, a new thought experiment is confronting these assumptions head-on and shaking the foundations of quantum physics.
This is interesting, but it does not affect any predictions of quantum mechanics. It only involves what one observer thinks that another observer is seeing.
Deutsch thinks the thought experiment will continue to support many-worlds. “My take is likely to be that it kills wave-function-collapse or single-universe versions of quantum theory, but they were already stone dead,” he said. “I’m not sure what purpose it serves to attack them again with bigger weapons.”
He is a die-hard supporter of the many-worlds interpretation. He apparently thinks that other interpretations have been shown to be "stone dead".

It is a little crazy to think that some stupid thought experiment is convincing about the existence of non-observable parallel universes.

Friday, December 7, 2018

China Has the Lead in Quantum Encryption

The NY Times reports:
The Race Is On to Protect Data From the Next Leap in Computers. And China Has the Lead.

The world’s leading technology companies, from Google to Alibaba in China, are racing to build the first quantum computer, a machine that would be far more powerful than today’s computers.

This device could break the encryption that protects digital information, putting at risk everything from the billions of dollars spent on e-commerce to national secrets stored in government databases.

An answer? Encryption that relies on the same concepts from the world of physics. Just as some scientists are working on quantum computers, others are working on quantum security techniques that could thwart the code-breaking abilities of these machines of the future.

It is a race with national security implications, and while building quantum computers is still anyone’s game, China has a clear lead in quantum encryption. As it has with other cutting-edge technologies, like artificial intelligence, the Chinese government has made different kinds of quantum research a priority.

“China has a very deliberate strategy to own this technology,” said Duncan Earl, a former researcher at Oak Ridge National Laboratory who is president and chief technology officer of Qubitekk, a company that is exploring quantum encryption. “If we think we can wait five or 10 years before jumping on this technology, it is going to be too late.”
This is ridiculous. I am a quantum computer skeptic, but put that aside. Quantum encryption can be done on a small scale, but it is commercially useless for many reasons. Messages cannot be authenticated. It is slow and cumbersome. It is subject to hardware attacks. It has never worked as well as the models assume. It does not solve any problem that is not already solved in a much better way.
With communications sent by traditional means, eavesdroppers can intercept the data stream at every point along a fiber-optic line. A government could tap that line just about anywhere. Quantum encryption cut the number of vulnerable spots in the Beijing-Shanghai line to just a few dozen across 1,200 miles, Professor Lu said.
No, most data today is sent encrypted. Governments cannot just tap the lines at intermediate points, because they would just get encrypted data.
At places like the University of Chicago, researchers hope to go a step further, exploring what are called quantum repeaters — devices that could extend the range of quantum encryption.
Yes, that is one of the big problems with quantum encryption. Ordinary encryption, as used today, can use cheap routers with no danger of security loss. Quantum encryption needs trusted quantum repeaters everywhere, and no one has invented one yet.

Wednesday, December 5, 2018

AAAS polls MeToo as a breakthrough

AAAS Science mag announces:
It’s that time of the year again: Science’s reporters and editors are homing in on the Breakthrough of the Year, our choice of the most significant scientific discovery, development, or trend in 2018. That selection, along with nine runners-up, will be announced when the last issue of the year goes online on 20 December. ...

The #MeToo movement made significant gains in science. Several institutions upheld long-standing allegations against prominent scientists accused of sexual harassment, discrimination, or bullying, and a U.S. National Academies of Sciences, Engineering, and Medicine report called for systemic changes to prevent such abuse. ...

Editor’s note: We originally included the claim of gene-edited babies as a candidate; we have since removed it to avoid giving the mistaken impression that Science endorses this ethically fraught work.
So AAAS views #MeToo as a scientific breakthrough, and endorses that ethically fraught work?!

The winner is being determined by an online vote, so we will see if the feminists have taken over.

Recent victims of #MeToo include Larry Krauss and Neil DeGrasse Tyson. I am not going to repeat the gossip here. In one accusation, a fan showed him a solar system tattoo on her arm, and he asked to see if it included Pluto. I thought that women get tattoos to show them. The accusations are extremely petty, and do not belong in a science journal.

Complaining about MeToo accusers is like complaining about termites. Termites do what termites do. It is unfortunate to see the leading science popularizers get maligned like this. Who is going to take on the responsibility to explaining science to the public? Maybe eunuchs or lesbians or Moslems will have to be recruited.

Maybe 2018 will go down in the history of science as the beginning of the end of modern physics. The period started with Maxwell and others in the late 19th century. Now physics news is dominated by ridiculously overhyped bogus stories about the multiverse and other nonsense, failed attempts to find susy particles and quantum computers, censoring physicist Alessandro Strumia for telling the truth about women in physics, and the MeToo movement sabotaging careers.

Monday, December 3, 2018

The Einstein God Letter is for sale

An auction is selling an Einstein letter that says:
The word God is for me nothing but the expression of and product of human weaknesses, the Bible a collection of venerable but still rather primitive legends,” the message reads. “No interpretation, no matter how subtle, can (for me) change anything about this. ...

For me the unadulterated Jewish religion is, like all other religions, an incarnation of primitive superstition. And the Jewish people to whom I gladly belong, and in whose mentality I feel profoundly anchored, still for me does not have any different kind of dignity from all other peoples. As far as my experience goes, they are in fact no better than other human groups, even if they are protected from the worst excesses by a lack of power. Otherwise I cannot perceive anything ‘chosen’ about them.
In spite of these opinions, being a Jew was very important to Einstein, and he was involved in Zionist causes all his life.

Judaism is funny that way. Many Jews identify with Judaism and Jewish culture very strongly, even tho they do not seem to believe in any of the religious aspects.
“Einstein often uses the word God — ‘God does not play dice with the universe,’” Rebecca Newberger Goldstein, who teaches philosophy and wrote “Plato at the Googleplex: Why Philosophy Won’t Go Away,” said in an interview. “A lot of physicists do this. It misleads people into thinking they’re theists, they believe in God. It’s a metaphorical way of talking about absolute truth. Einstein used it metaphorically and playfully.”

She said he had been religious when he was a child but “lost his religion and science took over.”
This is confusing to non-physicists. Saying that "science took over" is not right either, as Einstein had his share of unscientific beliefs.