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From Feb. 20, 2020.
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?
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.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.
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.
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.This is cleverly written to convince you that Minkowski derived a 4D geometry version of relativity from Einstein's work. This is not true.
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 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.