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Physicists and Philosophers Debate the Boundaries of Science

quantamagazine.org

71–80 of 168 posts

Re: Physicists and Philosophers Debate the Boundaries of Science

#71
post #57

Earlier quoted context omitted.

No one is arguing whether science is over, they are arguing whether modern theoretical physics is science. Another thing somewhat impacted by this issue that people don't think about is that we might not be able to keep up this pace in research for things like string theory for non-scientific reasons: specifically, science funding has flat-lined while the number of students entering the fundamental research fields is…

> science funding has flat-lined while the number of students entering the fundamental research fields is increasing This is probably not true. All kinds of money is being poured into physics research to create better batteries for example. It may be indirect, but there's a ton of money going into physics research.

> This is probably not true. All kinds of money is being poured into physics research to create better batteries for example. It may be indirect, but there's a ton of money going into physics research.

This is not research (in particular not physics research) but engineering or development.

Re: Physicists and Philosophers Debate the Boundaries of Science

#72
post #21

Earlier quoted context omitted.

Atomism is a good example of how philosophy first made up a theory that was later confirmed (in a changed version). https://en.wikipedia.org/wiki/Atomism You could also derive the Atomic nature of matter through math though, as infinitely devisable sets end up with paradoxes that don't match up with reality (think banarch-tarski) You can do all this without an idea how to test it.

Given the knowledge available 2000+ years ago, atomism was a surprisingly good idea. Yah, they got a lot of the details wrong, but that basic idea that reality is made up of basic "building blocks" that combine into the larger structures we can observe is basically correct. The philosophers that invented atomism probably thought about how the might see their atoms directly. I wonder how many "crazy" ideas were dreame…

Well, there is the case of Aristarchus who came up with the heliocentric model of the solar system about 1800 years or so before Copernicus. His model was rejected because of experimental evidence -- the theory predicted stellar parallax which observation at the time could not detect! (Of course, we can detect it now that telescopes have been invented -- the stars are just so much farther away than anyone could have possibly believed at the time.)

Re: Physicists and Philosophers Debate the Boundaries of Science

#73
post #48

This crisis in Physics makes me happier than anyone can know. It signals the end of the dominance of Kantian philosophy in Physics. Mach's principle (Einstein's polestar), Popperian falsifiability, Cantor's paradise of infinity (as described by Hilbert) and all other derivatives of Kant are the dead-end of a false metaphysics and epistemology. We do indeed, live in interesting (or depending on your worldview, dangero…

What does physics have to do with Cantor.

To get to Cantor's theories you have to accept his concept of a "completed infinity". This implies that infinity is a metaphysical concept, i.e. that infinity really exists in the universe. For example, do you believe that black holes are really infinite density or does an infinite property indicate a breakdown in the equations or theory, i.e. infinity is an epistemological concept. Modern physics is not consistent on this question but the error and question all derive from Kant.

Re: Physicists and Philosophers Debate the Boundaries of Science

#75
post #30

Earlier quoted context omitted.

> Physics used to be "hard science" - Physics is still a hard science. However, the edges of physics are difficult to test. > In cosmology, you can only observe, not experiment Saying that is like saying "we don't know evolution is true, because we don't see new species evolve every day". It's a naive approach to science. In both cases, you can use theories to make predictions about new things to look for. e.g. http:…

The NFL is funded because it provides entertainment, and we all know how well that sells.

The German word for entertaiment is "Unterhaltung", which is composed of "unten" and "halten" ("down" and "hold") - and that is what entertainment is: Holding the masses down (such that they don't ascend or revolt).

Guess who is thus interested in funding entertainment.

Re: Physicists and Philosophers Debate the Boundaries of Science

#76
post #15

Physics used to be "hard science" - if it wasn't testable, it wasn't meaningful. Physicists used to look down on other sciences for that reason. This article shows how much worse things have become. Nobody can figure out a way to test string theory. In cosmology, you can only observe, not experiment. As the article points out, the big questions are out of reach for scaling reasons. Trying to fix the problem through w…

There are different kinds of "testable".

Some theories are so easy to test, a 4th grader in her science class can test it conclusively in half an hour. We don't even question these theories anymore, because they've been set in stone for centuries.

Some theories take millions of dollars and several years to test, but they're manageable by large research universities and governments. At the very edge of this range, we have things like the Large Hadron Collider testing the existence of the Higgs boson. That one actually cost a few billion dollars and several decades, but we could live with that.

Some theories will take trillions of dollars and several centuries to test. Perhaps it will be quadrillions of dollars and several millennia instead, or even several million years. Right now, we don't even know what kind of technology we will need to test string theory. Perhaps we'll need to evolve into something else before our brains can even imagine what it would take to test it. But eventually we'll get there, if we learn to accept that science is bigger than all of us and stop being so impatient.

The difference between these three kinds of "testable" are quantitative, not qualitative. It just looks qualitative because the quantities involved are so huge. But if someone cannot grasp the idea of a theory that takes aeons to develop and test, I don't think they're qualified to judge the merits of theoretical physics.

Re: Physicists and Philosophers Debate the Boundaries of Science

#77
post #15

Physics used to be "hard science" - if it wasn't testable, it wasn't meaningful. Physicists used to look down on other sciences for that reason. This article shows how much worse things have become. Nobody can figure out a way to test string theory. In cosmology, you can only observe, not experiment. As the article points out, the big questions are out of reach for scaling reasons. Trying to fix the problem through w…

> Nobody can figure out a way to test string theory.

That's why some consider it physics inspired branch of math. For now.

> why should they be funded?

Until we have room temperature superconductors they are note done.

Re: Physicists and Philosophers Debate the Boundaries of Science

#78

Earlier quoted context omitted.

> The Bayesian approach is to assign a prior distribution to various theories of this nature. Because there are infinitely many possible priors, most exceedingly complicated (because the set of priors of complexity I don't think this would be a very compelling argument for Occam's razor if you didn't already believe it. This argument says you can't assign high probability to all "complex" theories, but it doesn't see…

I didn't claim it did - all I said is that this gives Occams Razor as an asymptotic law. Intuitively, I'm claiming: Lim_{complexity -> infinity} P(theory having fixed complexity) = 0 Stated more precisely, fix a prior distribution, then for any epsilon > 0, I can find a complexity cutoff C (which depends on the prior) so that P(any theory with complexity > C being true) This doesn't mean that P(theory|complexity) is…

Here's an argument that runs completely parallel:

jwmerrill's razor: points in the plane should be considered to be close to the origin unless there is evidence otherwise.

Is this a reasonable law? As reasonable as Occam's razor? I think probably not, but I don't have a strong opinion. One interesting thing to note is that the law doesn't say where the origin is (similarly, Occam's razor is vague about what exactly is meant by "simple" and "complex").

Finite asymptotic form: for any finite point set, there is a distance D such that no point in the set is further from the origin than D.

Continuous asymptotic form: given any function from points in the plane to non-negative numbers which has a finite integral, there is a distance D such that the integral of the function over the region that is further from the origin than D is less than any epsilon_1, and such that the function is everywhere less than any epsilon_2 on this region except perhaps on a set of measure 0.

The asymptotic forms are provable mathematical statements, but I think it would be a mistake to say that either of them is a very compelling argument for the original statement of "jwmerrill's razor."

Without intending to call you out in particular (I don't know what opinions you hold), I think people sometimes accept some odd logic in probability theory that they would be less likely to accept in other contexts. Bayesian probability theory provides practical solutions to a lot of interesting problems, and I personally wish people would emphasize those cases more, and make fewer sweeping statements about it being a consistent theory of all of the scientific method.

Re: Physicists and Philosophers Debate the Boundaries of Science

#79
post #45

"Massimo Pigliucci, a philosopher at the Graduate Center of the City University of New York, pointed out that falsifiability is woefully inadequate as a separator of science and nonscience, as Popper himself recognized. Astrology, for instance, is falsifiable — indeed, it has been falsified ad nauseam — and yet it isn’t science." You could say the same for phlogiston or N-rays. Falsifiable hypotheses that actually ge…

Just shows how sad academia is. Wouldn't be the first time I'm seeing those guys ponder endlessly on something other people say or do without bothering to really understand what those others are thinking and trying to achieve. BTW, is astrology actually falsifiable? I'm under impression that astrologists deliberately strive for unfalsifiability exactly to avoid falsification which could cast doubt on their wisdom.

> BTW, is astrology actually falsifiable? I'm under impression that astrologists deliberately strive for unfalsifiability exactly to avoid falsification which could cast doubt on their wisdom.

It is. Just do the following experiment:

Find, say, ten persons and an (or many) astrologists and let them create a horoscope (say, either a prognosis for the future or description of character traits) for these 10 persons, where only the exact time and location of birth is given to the astrologists.

After that give all ten horoscopes to all ten persons and let them rank. Now just formulate some sensible statistical model and voila - falsified.

Re: Physicists and Philosophers Debate the Boundaries of Science

#80
post #34

We had a rush of scientific breakthroughs 100 years ago. I believe we will have more. That experimentation in physics has slowed down to 18th century levels doesn't mean science is over, it just means the low-hanging fruit is over and we will have to continue slogging through theory before we discover new experiments. Science has always relied on philosophy for its underlying direction, it's just obvious again. It to…

Science slowed down in the 50s right when government got involved in a massive way in the grant process. Eisenhower even bemoaned this fact, along with the military/industrial complex in his final speech:

"In this revolution, research has become central; it also becomes more formalized, complex, and costly. A steadily increasing share is conducted for, by, or at the direction of, the Federal government. Today, the solitary inventor, tinkering in his shop, has been overshadowed by task forces of scientists in laboratories and testing fields. In the same fashion, the free university, historically the fountainhead of free ideas and scientific discovery, has experienced a revolution in the conduct of research. Partly because of the huge costs involved, a government contract becomes virtually a substitute for intellectual curiosity. For every old blackboard there are now hundreds of new electronic computers. The prospect of domination of the nation's scholars by Federal employment, project allocations, and the power of money is ever present and is gravely to be regarded. Yet, in holding scientific research and discovery in respect, as we should, we must also be alert to the equal and opposite danger that public policy could itself become the captive of a scientifictechnological elite."

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