Monday, February 17, 2020

Randomness cannot be empirically shown

A new paper argues:
We consider the nature of quantum randomness and how one might have empirical evidence for it. We will see why, depending on one's computational resources, it may be impossible to determine whether a particular notion of randomness properly characterizes one's empirical data. Indeed, we will see why even an ideal observer under ideal epistemic conditions may never have any empirical evidence whatsoever for believing that the results of one's quantum-mechanical experiments are randomly determined. This illustrates a radical sort of empirical underdetermination faced by fundamentally stochastic theories like quantum mechanics.
Isn't this obvious?

A lot of people say that quantum mechanics shows that the world is intrinsically random, or objectively random, or some such nonsense. There is no empirical support for such statements. For one thing, there could be a superdeterminism that makes nothing random.

We say that coin tosses are random, because nobody goes to the trouble of tracking all the variables needed to predict the outcome.

We say radioactive decay is random, because there is no known way of predicting the precise decay time. But it seems possible that we could, if we knew more about about the state of nucleus in question.

The paper discusses tests for coin toss sequences to appear random, but we have no way of recognizing intrinsic randomness even if we saw it.

Wednesday, February 12, 2020

More millions for quantum BS

The NY Times reports:
SAN FRANCISCO — White House officials on Monday unveiled plans to increase federal funding for the development of artificial intelligence and quantum computing, two cutting-edge technologies that defense officials say will play a key role in national security.

The funding, part of the Trump administration’s $4.8 trillion budget proposal, would direct more money for A.I. research to the Defense Department and the National Science Foundation. The administration also wants to spend $25 million on what it calls a national “quantum internet,” a network of machines designed to make it much harder to intercept digital communication.

For several years, technologists have urged the Trump administration to back research on artificial intelligence — which could affect things as diverse as weapons and transportation — and quantum computing, a new way to build super-powerful computers. China’s government, in particular, has made building these machines a priority, and some national security experts worry that the United States is at risk of falling behind.

The proposed spending follows earlier administration moves. In 2018, President Trump signed a law that earmarked $1.2 billion for quantum research. The Energy Department recently began distributing its portion of that money — about $625 million — to research labs in industry, academia and government.

“The dollars we have put into quantum information science have increased by about fivefold over the last three years,” said Paul Dabbar, under secretary for science at the Energy Department, in an interview.
I actually wish that this were legitimate. It would be an exciting area of cryptologic research, and open up a whole new arena for security analysis.

But it is all bogus. There is no practical value to a quantum internet.

Monday, February 10, 2020

Rovelli rejects Eternalism

Physicist Carlo Rovelli just wrote an essay on the philosophy of time, favoring Neither Presentism nor Eternalism. He relies heavily on "Einstein’s conventional definition of simultaneity", without mentioning that the notion is entirely due to Poincare, years before Einstein.

Shortly after the formulation of special relativity, Einstein's former math professor Minkowski found an elegant reformulation of special relativity in terms of the four dimensional geometry that we call today Minkowski space. Einstein at first rejected the idea. (`A pointless mathematical complication'.) But he soon changed his mind and embraced it full heart, making it the starting point of general relativity, where Minkowski space is understood as the local approximation to a four-dimensional, pseudo-Riemannian manifold, representing physical spacetime.

The mathematics of Minkowski and general relativity suggested an alternative to Presentism: the entire four-dimensional spacetime is `equally real now', and becoming is illusory. This I call here Eternalism.
This is cleverly written to convince you that Minkowski derived a 4D geometry version of relativity from Einstein's work. This is not true.

Poincare was the first to formulate a 4D geometry version of relativity, and that paper was written before Einstein published anything on the subject. Minkowski's 4D space was developed directly from Poincare's work, not Einstein. Minkowski does cite Einstein's paper, but does not use anything from it, and it is not clear that Einstein had any influence on Minkowski at all. From Poincare's paper, Minkowski gets the 4D formalism, the pseudo-Riemannian metric, the 4D Lorentz transformations, and the 4D covariance of Maxwell's equations.
This subtle mistake of McTaggart is the same mistake as that which lies at the root of Eternalism. The ensemble of the events of the world is four-dimensional, and we can embrace it within a single image. But this is not a denial of becoming, no more than a single chart of the British royal dynasties is a denial of the fact that events happened in England along the centuries.
Rovelli is right that believing in relativity and using Minkowski does not a belief that all times exist at once. Some people seem to believe that relativity requires determination and a denial of the present. One can still have different philosophical views of time.