Trying to test Many-Worlds

David Deutsch is a big proponent of the Many Worlds Interpretation of quantum mechanics, and writes The Logic of Experimental Tests, Particularly of Everettian Quantum Theory

By adopting a conception – based on Popper’s – of scientific theories as conjectural
and explanatory and rooted in problems (rather than being positivistic, instrumentalist and rooted in evidence), and a scientific methodology not involving induction, confirmation, probability or degrees of credence, and bearing in mind the decision-theoretic argument for betting-type decisions, we can eliminate the perceived problems about testing Everettian quantum theory and arrive at several simplifications of methodological issues in general.

This is what you get when you reject positivism. You can decide to believe in parallel universes with no evidence, because only the positivists insist on being rooted in evidence. Deutsch even claims that the parallel universe theory is testable, because of some philosophical misdirection.

n explanation is bad (or worse than a rival or variant explanation) to the extent that…

(i) it seems not to account for its explicanda; or
(ii) it seems to conflict with explanations that are otherwise good; or
(iii) it could easily be adapted to account for anything (so it explains nothing).

It follows that sometimes a good explanation may be less true than a bad one (i.e. its true assertions about reality may be subset of the latter’s, and its false ones a superset).

This sort of reasoning allows him to accept explanations that are not really true.

Scientific methodology, in turn, does not (nor could it validly) provide criteria for accepting a theory. Conjecture, and the correction of apparent errors and deficiencies, are the only processes at work. And just as the objective of science isn’t to find evidence that justifies theories as true or probable, so the objective of the methodology of science isn’t to find rules which, if followed, are guaranteed, or likely, to identify true theories as true.

This is anti-positivism.

I take the positivist view that science has established the truth of theories like Newtonian gravity for celestial mechanics, within a suitable domain of applicability. The theory lets you can make observations, fit a model, and make predictions of orbits with error estimates.

Yes, general relativity makes more precise predictions in some extreme cases, and gives a more satisfactory causal explanation, but the original Newtonian theory is still valid within its limits.

But one thing that cannot be modelled by random numbers is ignorance itself (as in the ‘ignorance interpretation of probability’).

Deutsch and other many-worlds advocates are very unhappy with probability, because they have to idea how to say that some of the parallel worlds are more likely than others, and hence cannot make sense out of probabilistic experiments.

So Deutsch says that the answer is to reject positivism and be very broad-minded about what is accepted as a explanation.

History of the quantum leap

German professor Herbert Capellmann writes on The Development of Elementary Quantum Theory from 1900 to 1927:

The basic laws of classical physics relied upon the principle ”Natura non facit saltus” (nature does not make jumps), transmitted from ancient philosophy. The underlying assumption was the existence of a space-time continuum and all changes in nature should occur continuously within this space-time continuum. Starting towards the end of the 17’th century, the classical laws governing these changes were expressed in form of differential equations or variational principles, where infinitesimally small changes of various physical variables are related to each other. Typically these differential equations of classical physics possessed exact solutions for given initial and boundary conditions, at least in principle. This led to the general conclusion that nature is deterministic; the state of nature at any given time was believed to be related in a unique way to its state at any past or future time. Even if the development of statistical thermodynamics related probabilities to thermodynamic variables, these probabilities were meant to describe insufficient knowledge of details due to the large numbers of microscopic particles involved, but deterministic behavior of all individual processes was not questioned. ...

Born, Werner Heisenberg and Pascual Jordan in 1925, are contained in:

The basic principles of Quantum physics:
- On the microscopic level all elementary changes in nature are discontinuous,
consisting of quantized steps: ”quantum transitions”.
- The occurrence of these quantum transitions is not deterministic, but governed by probability laws.

No, this is a very strange statement of the QM basic principles.

(He means atomic level, not microscopic level.)

Position, momentum, time, frequency, energy, etc. are not necessarily discrete. The wave function for an electron is typically a continuous function of space and time, and progresses smoothly according to a differential equation. So it is just wrong to say everything is discontinuous.

The emphasis on probabilities is also misleading, as he concedes that other physics theories also hinge on probabilities. He distinguishes QM by whether "insufficient knowledge" is involved, but that is just a philosophical issue.

The path towards the future Quantum Theory is defined as

”the systematic transformation of classical mechanics into a discontinuous atomic mechanics..... the new mechanics replaces the continuous manifold of (classical) states by discrete manifold, which is described by ”quantum numbers”....
quantum transitions between different states are determined by probabilities...
the theoretical determination of these probabilities is one of the profound tasks of Quantum Theory....”.

Some problems have a discrete spectrum, but all this talk about a discrete manifold is misleading.

The essence of QM is that the observables are represented by non-commuting linear operators.

The core of the theory is continuous, with continuous spacetime, continous wave functions, etc. For all we know, light is continuous, but only shows properties at discrete frequencies sometimes because some continuous problem has a discrete spectrum. Even then, that spectrum can often be perturbed by applying an electric or magnetic field.

Old monkeys lose interest in toys

The NY Times Science section is pretty good, but it misses a lot of pure science stories because it prefers stories that somehow illuminate what it means to be human, especially if there is a leftist slant.

Here is the latest example:

Humans spend less time monkeying around as they get older, and according to a study published Thursday, so do monkeys.

As anyone who has ever hung out with a grandparent, observed a retiring parent, or grown old themselves may know, many people get pickier with age. ...

The researchers found that the monkeys’ interest in toys waned when they became reproductive. And around 20, (their “retirement age”) monkeys, like humans, had fewer social contacts and approached others less frequently. ...

How human behavior changes as we age could therefore have some biological origins. ...

Dr. Freund said she sees the same behavior patterns in humans.

So the lesson here is that we are just the same as the monkeys we split from 25M years ago. Leftists love the idea that we are just monkeys.

But there is no reason to believe that our relation to monkeys has anything to do with the result.

Perhaps monkeys and humans just lose stamina with age, and maybe the monkeys are too tired to deal with relationships that are ambivalent or negative, she added. Or maybe, as the researchers are now trying to investigate, aging monkeys are less socially interactive because they tend to take fewer risks, which is what appears to happen in humans according to some research.

Whatever the reason behind the behavior of these distantly-related species is, there’s a take-home message for humans: “Our behaviors that seem very much the result of our deliberation and choice,” said Dr. Freund, “might be more similar to our primate ancestors than we might think.”

So it is not in our genes at all. These are just choices that any thinking species might make.

So is anything new or surprising?

Here is some more obvious research. A medical journal reports that men are more willing to risk unsafe sex if the woman is extremely attractive.

Back from the parallel universe

This is pun about parallel parking.

Lobbying for the exascale computer

The NY Times reports:

Last year, the Obama administration began a new effort to develop a so-called “exascale” supercomputer that would be 10 times faster than today’s fastest supercomputers. (An exaflop is a quintillion — one million trillion — mathematical instructions a second.) Computer scientists have argued that such machines will allow more definitive answers on crucial questions such as the danger posed by climate change.

It is funny what scientists will say to get funding. If saying that anthropogenic global warming is a proven fact gets them funding, they say that. But if then saying that we need an exascale supercomputer will prove it, they say that to get funding for those exaflops.

Philosopher errors about free will

I listened to some dopey philosophers discuss free will, and they agreed on several absurd points.

Science has proved that the world is deterministic.

No, our leading scientific theories are not deterministic. Quantum mechanics is the most fundamental, and it is not deterministic at all. The most deterministic theory is supposed to be Newtonian mechanics, but it is not deterministic as it is usually applied.

Regardless of empirical knowledge, a rational materialistic view requires determinism.

I don't know how anyone can believe anything so silly. Nearly all of science, from astrophysics to social science, uses models that are partially deterministic and partially stochastic. Pure determinism is not used or believed anywhere.

Random means all possibilities are equally likely.

No. Coin tosses are supposed to have this property, but anything more complicated usually does not. If you allow the possibility of the coin landing on it edge, the edge is not equally likely.

Randomness means no one has any control over outcomes.

No, it means nothing of the kind. Often the randomness is a scientific paper is controlled by a pseudorandom number generator. While those numbers look random compared to the other data, they are determined by a formula.

The world is either deterministic or random, so we have no free will.

I wrote an essay explaining why this is wrong.

This is the sort of thing that only a foolish philosopher would say. Free will is self-evident. And yet they claim that it does not exist based on some supposed dichotomy between two other concepts that they never adequately define.

They might define randomness as anything that is not determined. Then they try to draw some grand philosophical consequence from that dichotomy. No, you cannot prove something nontrivial just by giving a definition.

Physicists with faith in the multiverse

Peter Woit reports:

So, from the Bayesians we now have the following for multiverse probability estimates:

Carroll: “About 50%”
Polchinski: “94%”
Rees: “Kill my dog if it’s not true”
Linde: “Kill me if it’s not true”
Weinberg: “Kill Linde and Rees’s dog if it’s not true”

Not quite sure how one explains this when arguing with people convinced that science is just opinion.

Neil comments:

When a weather forecaster tells me the probability of rain tomorrow is 50%, I translate it as “I don’t know.” With a greater than 50%, I hear “There is more reason to think it will rain than it won’t” and vice versa with less than 50%.

No, this is badly confused.

If you really don't know anything, then you can apply the Principle of indifference to say that both possibilities have a 50% prior. But that is certainly not what the weather forecaster means. He is says that when historical conditions have matched the current conditions, it has rained 50% of the time. That is very useful, as a typical day will usually have a much less chance of rain (in most places).

A multiverse probability estimate does not refer to other instances that may or may not have been multiverse. So all the probability can mean is a measure of the speaker's belief. This is not any evidence for the multiverse, so it is like a measure of one's faith in God.

New black hole collision announced

A reader alerts me to this:

Why does Ligo's reported second detection of gravitational waves and a black hole merger look absolutely nothing like the first detection announced in Februaray?

There are more details at the LIGO Skeptic blog.

I don't know. I am also wondering why they are just now announcing a collision that was supposedly observed 5 months ago, and whether LIGO still has its policy of only 3 people knowing whether or not the result has been faked.

And why do they sit on the data so long? The LIGO folks could tell us whenever they have a coincident event. As it is, they are not telling us the full truth, because they make big announcements while concealing the data that would allow us to make comparisons.

Dawkins against First Cause argument

Leftist-atheist-evolutionist summarizes a Dawkins speech:

As you may recall, in The God Delusion Richard argued that the “First Cause” argument is intellectually bankrupt, for it doesn’t explain the “cause” of a complex God who could create everything. In response, the dimmer or more mendacious theologians say that God isn’t complex at all, but simple. (Some theologians, however, just punt and say that God is the One Thing that Doesn’t Need a Cause.) It is this “simple god” argument that Dawkins takes apart halfway through the video. And, of course, even if God were simple, his appearance in the cosmos still needs an explanation. It just won’t do to say that God is the one thing, among all other things, that doesn’t need a cause. If he was hanging around forever, pray tell us, O theologians, what he was doing before he created the Universe.

Finally, physics has dispensed with the idea of causation; the discipline has no such thing as “a law of cause and effect,” and some physical phenomena are simply uncaused.

If he just said that theologians cannot explain the cause of God, then I would agree.

But then the argument is that God requires a causal explanation, and then nothing else does!

How could Dawkins and Coyne think that "physics has dispensed with the idea of causation"? Does some textbook say that?

All my textbooks say that events are caused by events in the backward light cone, with causation propagated by differential equations.

All of our modern science theories are based on causality. From what we know, everything has causes that are earlier in time.

If you ask what caused the big bang, then no one has a good answer for that. You can say that there is no singularity. You can say that the singularity had no cause. You can say that the big bang is just an energy release in some larger multiverse. You can say God caused it. You can say turtles caused it. You can say a lot of things, but the subject is so far removed from the domain of established science that it is all just wild speculation.

Dawkins' speech was at something called the "2016 Reason Rally". Those guys must have a funny idea about what "reason" is.

Neil deGrasse Tyson now says that he does not call himself an "atheist" because that term is now understood to include various other ideologies. He has a point. If you called yourself a Baptist, then people would expect you to have views in line with the big Baptist organizations, rather than expect you to conform to some dictionary definition. Likewise atheist is not just someone who denies God, according to many today.

Meanwhile, Scott Aaronson posts a Trump-hating rant:

From my standpoint, Hillary does have four serious drawbacks, any one of which might cause me to favor an alternative, were such an alternative available: ...

Again, though: I regard Trump as an existential threat to American democracy and rule of law, of a kind I’ve never seen in my lifetime and never expected to see.

One of his arguments is that Trump proposed a temporary ban on Muslim immigration.

No, Islam is the existential threat, and Trump recognizes that. Aaronson posted that before the recent gay bar shooting.

Here is more Trump-hating:

Ms. Whitman, according to one of the people present, did not stop at comparing Mr. Trump to Hitler and Mussolini.

Okay, maybe Islam and the Trump-haters are the existential threats.

Google seeking universal quantum computer

Nature mag reports:

Google moves closer to a universal quantum computer

Combining the best of analog and digital approaches could yield a full-scale multipurpose quantum computer.

For 30 years, researchers have pursued the universal quantum computer, a device that could solve any computational problem, with varying degrees of success. ...

This new approach should enable a computer with quantum error correction, says Lidar. Although the researchers did not demonstrate that here, the team has previously shown how that might be achieved on its nine-qubit device2.

“With error correction, our approach becomes a general-purpose algorithm that is, in principle, scalable to an arbitrarily large quantum computer,” says Alireza Shabani, another member of the Google team.

The Google device is still very much a prototype. But Lidar says that in a couple of years, devices with more than 40 qubits could become a reality.

“At that point,” he says, “it will become possible to simulate quantum dynamics that is inaccessible on classical hardware, which will mark the advent of ‘quantum supremacy’.”

I post this for the benefit of those who think that quantum computers have already been built. As you can see, Google is really itching to claim the first quantum computer, and it hopes to do so in the next couple of years.

I doubt it, but we shall see. Google has done better with artificial intelligence than I expected, but worse in robotics. I am predicting that it does not demonstrate quantum supremacy.

Hawking pushes soft hair on black holes

A NY Times article brags about the latest research paper from Stephen Hawking and coauthors:

But there was a hitch. By Dr. Hawking’s estimation, the radiation coming out of the black hole as it fell apart would be random. As a result, most of the “information” about what had fallen in — all of the attributes and properties of the things sucked in, whether elephants or donkeys, Volkswagens or Cadillacs — would be erased.

In a riposte to Einstein’s famous remark that God does not play dice, Dr. Hawking said in 1976, “God not only plays dice with the universe, but sometimes throws them where they can’t be seen.”

But his calculation violated a tenet of modern physics: that it is always possible in theory to reverse time, run the proverbial film backward and reconstruct what happened in, say, the collision of two cars or the collapse of a dead star into a black hole.

The universe, like a kind of supercomputer, is supposed to be able to keep track of whether one car was a green pickup truck and the other was a red Porsche, or whether one was made of matter and the other antimatter. These things may be destroyed, but their “information” — their essential physical attributes — should live forever.

No, this is nonsense. There is no accepted principle that information should live forever.

At least in principle, then, he agreed, information is always preserved — even in the smoke and ashes when you, say, burn a book. With the right calculations, you should be able reconstruct the patterns of ink, the text. ...

But neither Dr. Hawking nor anybody else was able to come up with a convincing explanation for how that happens and how all this “information” escapes from the deadly erasing clutches of a black hole.

Indeed, a group of physicists four years ago tried to figure it out and suggested controversially that there might be a firewall of energy just inside a black hole that stops anything from getting out or even into a black hole.

The new results do not address that issue. But they do undermine the famous notion that black holes have “no hair” — that they are shorn of the essential properties of the things they have consumed. ...

But neither Dr. Hawking nor anybody else was able to come up with a convincing explanation for how that happens and how all this “information” escapes from the deadly erasing clutches of a black hole.

Indeed, a group of physicists four years ago tried to figure it out and suggested controversially that there might be a firewall of energy just inside a black hole that stops anything from getting out or even into a black hole.

The new results do not address that issue. But they do undermine the famous notion that black holes have “no hair” — that they are shorn of the essential properties of the things they have consumed. ...

“When I wrote my paper 40 years ago, I thought the information would pass into another universe,” he told me. Now he thinks the information is stored on the black hole’s horizon.

The general public must think that Hawking and other physicists are trolling us.

No, you cannot recconstruct a book after burning it, and you cannot recover info after dropping it into a black hole. Saying that the info stays on the horizon, or whatever Hawking is saying now, has no observable implications. The firewall idea is just more lunacy.

The idea that info lasts forever is promoted primarily the Everett many-worlds cult. They believe that irreversible experiments, like buring a book, are really just some sort of illusion, with all the info passing into a parallel universe. The info looks as if it is lost to our universe, but a trace of it is quantum entangled, so there is some infinitesimal probability it can be reinstated.

If that seems like gibberish to you, it is gibberish.

Musk says we live in a simulation

Elon Musk is today's most daring entrepreneur, and he says:

At Recode's annual Code Conference, Elon Musk explained how we are almost certainly living in a more advanced civilization's video game. He said: "The strongest argument for us being in a simulation probably is the following. Forty years ago we had pong. Like, two rectangles and a dot. That was what games were. Now, 40 years later, we have photorealistic, 3D simulations with millions of people playing simultaneously, and it's getting better every year. Soon we'll have virtual reality, augmented reality. If you assume any rate of improvement at all, then the games will become indistinguishable from reality, even if that rate of advancement drops by a thousand from what it is now. Then you just say, okay, let's imagine it's 10,000 years in the future, which is nothing on the evolutionary scale. So given that we're clearly on a trajectory to have games that are indistinguishable from reality, and those games could be played on any set-top box or on a PC or whatever, and there would probably be billions of such computers or set-top boxes, it would seem to follow that the odds that we're in base reality is one in billions. Tell me what's wrong with that argument. Is there a flaw in that argument?"

Maybe this is why Musk thinks that colonizing Mars is a good idea.

This is another argument against spending another billion dollars on quantum computer research.

By doing a lot of quantum experiments, we stress the ability of the simulator to keep up. These experiments put qubits into Schroedinger cat states, and there is no known efficient way to simulate cat states on a classical computer. So such simulations will slow down the frame rate, and effectively put us all in a state of suspended animation while the computations catch up.

Possibly the simulation would take short-cuts, and violate the laws of quantum mechanics. No one has seen that yet. Another possibility is that the game hardware of the future will have massively power quantum computers in them. But that is not part of Musk's argument, as there has been no progess in making a quantum computer more efficient than a classical computer.

If the quantum computer enthusiasts are right, Google will have a practical quantum computer in a couple of years. If so, then Google could be putting us all in a state of suspended animation, or maybe even killing us by making possible the quantum simulators that will make it likely that we are all only living in a simulation.

As the above summary says, "Tell me what's wrong with that argument. Is there a flaw in that argument?"

Scott Aaronson challenges the famous mathematical physicist Roger Penrose on the subject of computer consciousness, and says:

One thing I hadn’t fully appreciated before meeting Penrose is just how wholeheartedly he agrees with Everett that quantum mechanics, as it currently stands, implies Many Worlds. Penrose differs from Everett only in what conclusion he draws from that. He says it follows that quantum mechanics has to be modified or completed, since Many Worlds is such an obvious reductio ad absurdum.

Penrose has his own theories, but they are not widely accepted.

Saying that quantum mechanics, as it currently stands, implies Many Worlds, is not much different from saying that it implies quantum computers. It makes almost as much sense to me to say that living in a quantum simulator is an obvious reductio ad absurdum.

For us to be programs in a simulator, we would have to believe that computer consciousness is possible, and there is no consensus for that. There is not even any way to define consciousness or to detect it if you find it.

Penrose says consciousness hinges on quantum mechanics being modified to accommodate gravity, and such quantum gravity operations taking place in the brain.

Aaronson says that consciousness could hinge on living in an anti-DeSitter space so that the boundary of a black hole somewhere could enforce unitary of the wave function time evolution. But he concedes that we seem to live in a de-Sitter-like space, with photons escaping irreversibly.

Lumo comments on Penrose and Aaronson, as usual.

In the Matt Damon MIT Commencement Speech June 3 2016, he tells of prominent physicist who say that we might be living in a simulation. He also tells plenty of left-wing nonsense. I would think that this ought to be a symptom of schizophrenia. I mean thinking that we live in a simulation is crazy. Maybe some of the leftist nonsense also.