Wednesday, July 13, 2022

Next Quantum Computing Milestone will be in 2050

A new paper sketches the history of quantum computing:
We argue that quantum computing underwent an inflection point circa 2017. Long promised funding materialised which prompted public and private investments around the world. ...

We argue that the next inflection point would occur around when practical problems will be first solved by quantum computers. We anticipate that by 2050 this would have become commonplace, were the world would still be adjusting to the possibilities brought by quantum computers.

Note that the big advance of 2017 was in funding, not technological progress.
A turning point in the development of quantum computation appears around 2017. At this point, several long-promised large funding programs began such as the European Quantum Flagship and the American National Quantum Initiative Act (this happened around the world and was in the Billions of USD). Most national investments appear to keep a country compet- itive in technological development. There are many initiatives around the world adding up to more than 20 billion USD committed public funding. In addition, many private companies also invested dramatically around this time. Mean
We have to wait a long time for the next milestone.
When will we see another inflection point? It’s hard to tell. The saying goes that knowl- edge begets knowledge. And so development always seems to go increasingly faster. But the next jump might have to wait until practical problems of commercial value are regularly solved. This should take place perhaps even around 2050.
I reported here in 2019 that progress was doubly exponential. If that were true, we would already see commercial value. Instead we have to wait 28 more years.

I don't believe it. We will not see those commercial applications. I also don't believe that it will get billions in funding for three decades without commerical payoff.

My prediction is that in about ten years, everyone will be complaining that quantum computing failed because the funding dried up.

Monday, July 11, 2022

Capturing the Central New Lesson of the Quantum

Physicist John Wheeler once wrote:
What one word does most to capture the central new lesson of the quantum? ‘Uncertainty,’ so it seemed at one time; then ‘indeterminism’; then ‘complementarity’; but Bohr’s final word ‘phenomenon’ – or, more specifically, ‘elementary quantum phenomenon’ – comes still closer to hitting the point. [...] In today’s words, no elementary quantum phenomenon is a phenomenon until it is a registered (‘observed’ or ‘indelibly recorded’) phenomenon, ‘brought to a close’ by an ‘irreversible act of amplification’. (Miller and Wheeler, 1984)57
Brian Greene comments on the view that the essence of the quantum is entanglement. Maybe superposition is second. But he says that when he was in school, no one made a big deal out of entanglement.

I don't think any of these are so central to quantum mechanics. Yes, in a quantum mechanical system, particles are usually entrangled with others. But would you say that the essence of solar system gravity is that every planet exerts a force on every other? Maybe, but I doubt it.

Scott Aaronson has weighed in on the Bohr-Einstein debates. I added this comment:

If you believe in MWI, then both Bohr and Einstein completely missed what quantum mechanics is about. What makes QM unusual is not measurement, or entanglement, or superposition, or probability, or complementarity. It is the continuous splitting of the universe into parallel worlds, where essentially everything happens somewhere.

While Bohr and Einstein did not find Bell’s Theorem, they were probably aware of von Neumann’s 1932 textbook with a theorem that had similar conclusions. That is, under certain hypotheses, QM cannot be recast as a theory of classical variables.

Aaronson notes that von Neumann's assumptions have been criticized. Yes, that is true, but not the conclusion. Conventional wisdom has been since 1932 that a theory of classical variables will not work. So I do not think that Bell's theorem would have affected Bohr or Einstein at all.

The bigger issue is my first point. Aaronson and many others now say that they subscribe to many-worlds theory (MWI). If so, why is he even talking about these other issues? MWI is so bizarre and counter to science that it makes all the other issues trivial.

Saturday, July 2, 2022

Only Greeks had the Pythorean Theorem

From the Wikipedia List of common misconceptions
The Greek philosopher Pythagoras was not the first to discover the equation expressed in the Pythagorean theorem, as it was known and used by the Babylonians and Indians centuries before him.[641][642][643][644] He may have been the first to introduce it to the Greeks;[645][643] the first record of it being mathematically proved as a theorem is in Euclid's elements which was published some 200 years after Pythagoras, so he could have been the first to prove the theorem.
I don't think that there is a misconception here.

The Pythagorean theorem is named after Pythagoras, but he was a Greek who lived 2500 years ago, and no one know what he exactly did.

Ancient Babylonians and Indians had examples of right triangles with a2+b2=c2, but they did not have the theorem. As far as we know, only the Greeks invented mathematical proofs.

Babylon and India were doing arithmetic. Greece was doing real mathematics.

Speaking of math, Numberphile has a new video on 10272,000 universes in string theory, more than previously announced. In the middle it casually mentions that they all have negative energy, and are therefore unphysical. Ultimately this is what string theory will be famous for.