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V_V comments on How do you tell proto-science from pseudo-science? - Less Wrong Discussion
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Is it?
I'm not an expert, but isn't Tipler considered largely a pseudo-scientist?
The E8 theory of particle physics is also largely considered to be pseudoscience.
How do you tell whether those who claim it's pseudoscience are more reliable than those who claim it's not?
It's not a theory that makes quantitative predictions, it's more a blueprint for a future theory, and the critics would say that the blueprint is hopelessly flawed - that no such theory is mathematically possible.
The larger theoretical context of Lisi's work is the attempt to describe 4D gravity as a gauge theory, the viability of which is the central dispute between string and loop theories of quantum gravity. Lisi's theory is a "GraviGUT" theory which then adds to this problematic foundation, even wilder hopes about getting fermions from "BRST ghosts", and about finding loopholes in theorems which say that even then, you couldn't get the necessary three generations of them, out of a single E8 gauge field.
Incidentally, there are various ways to get three generations of particles "from E8" in string theory, so perhaps those should be regarded as the real "E8 theories".
I've looked at the theory myself, if that's what you mean (I have a background in mathematical physics). If you like, I can give more explanation about the severe drawbacks of the theory and why it's considered to be pseudoscience and probably not worthy of further investigation.
Those last six words are what I'd like to find out, as soon as possible, if it's possible to do so; and I would appreciate any assistance on that score. (I regularly read 'Not Even Wrong', whose author puts forward a strong case that string theory is also worth skipping; which doesn't leave too many possibilities on the ground to pick from, these days.)
As Mitchell pointed out below, there are severe theoretical issues. The theory predicts 22 new particles (and doesn't even specify their masses thus making detection difficult) and fails to account for the properties of many existing ones. Most importantly, the theory has no chirality, and chirality is extremely important for fundamental particles. This error is severe and no way to avoid it has been found. E8 does crop up in string theory in other settings but it's unrelated to Lisi's work.
A deeper problem is that the theory doesn't actually solve a lot of problems, even if it were true. You mentioned Not Even Wrong; here is an excerpt from Peter Woit on the E8 theory:
I personally consider the publicity over the theory as simply a failure mode of science journalism. The theory got some tentative endorsement from some physicists (before they could look at it more deeply) and thus it was prematurely promoted by journalists despite not being distinguishable from the thousands of other theories-of-everything that crop up and never get any attention.
Fair enough.
Do you have any suggestions of other theories that would be better worth the time to read up on?
As others have said, it really depends what level you're on and what you're interested in. At the very least I recommend familiarity with quantum field theories before even attempting to touch more speculative physics. This includes general Yang-Mills theories and their algebraic underpinnings.
It's not accepted by the majority of the scientific establishment, so it's not "science". However, it's claims don't violate known physical law. If someone says that it has a 5% chance of working, and they'd be willing to pay 20x the cost of cryonics to cure themselves of a disease, that seems to fall within "arguably reasonable".
I listed the next item, which was a link to an interview with Tipler, as pseudo-science. Victor Stenger, who authored the other PDF in the line you quoted, seems to have his head on reasonably straight. And even if Tipler's beliefs are pseudo-scientific, the math involved in the two PDFs seems to check out, as best I can tell, without any reliance on anything on the pseudo-scientific side.
Whether something is a science has nothing to do with whether it violates physical law for which a consensus exists within the scientific community.
Paranormal is a much better word to describe those claims.
When Feynman made up the term cargo-cult science one of is prime examples was rat psychology research. Those researchers where doing experiment but the didn't do them in a way that really tested the claims they were investigating.
Pseudoscience is when you claim that there scientific evidence for a claim when there isn't. You aren't a pseudoscientist for investigating a hypothesis.
As ChristianKI already said, whether something strictly violates known physical laws is a poor criterion for telling science from pseudoscience. According to that criterion, paradigm-breaking physical theories such as Einstenian relativity and quantum mechanics would have been pseudoscience when they were presented, while lots of medical snake oil (including literal snake oil) would be not.
But it hasn't been established that cryonics has a 5% chance of working, or even a 0.25% chance.
I haven't had the time to read it yet, and this is not my field of expertise, but AFAIK attempts to reduce quantum physics to classical physics have been around since quantum physics exists, and they have always turned out to be unsuccessful. Even Einstein dedicated a large part of his research to that goal, to no avail.
Thus I don't expect any of them to succeed anytime soon. Past a certain point it stops being proto- and it starts to become largely pseudo-.
Since E8's predictions about a few new particles also violate currently known physical laws, that interpretation of 'pseudoscience' would include E8 - but in my rough definitions above, I've included E8 as coming closer to proto-science than pseudo-science; so I'm going to have to disagree with you about your described criterion matching the dividing line I'm trying to draw.
On the other paw, it hasn't been established that cryonics has a 5% chance of failure, or even a 0.25% chance. It seems worthwhile to determine what the relevant null hypothesis /is/, before determining in which direction the burden of proof lies. (Either that, or one could try a Feynman estimate. A 0.5% chance of success seems too low; and a 10% chance seems too high; so somewhere around 3% seems within the right order of magnitude.)
They're both quite short; I even managed to describe the ideas involved to a complete non-physicist:
[You are] probably familiar with Newtonian physics: force, mass, action and reaction, conservation of momentum, etc. The equations involved in all of that can be written out in different ways, which all add up to the same things, like x=y is the same as x-y=0. One if those ways is called the Hamilton-Jacobi Equation, which is one of the more powerful and general versions, but with a flaw - it's "non-deterministic", meaning it's rubbish at telling you what actually would happen when particles interact. Fortunately, it's possible to add a term to H-J, which arises from adding the premise that "God does not play dice with the universe" (aka 'determinism', something which physicists prize in such equations), which fixes that flaw. A surprising consequence of doing so is that the H-J equation can then be rearranged into another equation: the Schrodinger Equation, which is the foundation of quantum mechanics. Which means that all that quantum mechanics really is nothing more or less than classical physics, where all the different possible sequences of events happen in their own 'universes', and which can affect each other as long as any given particle has a similar enough position&momentum to a particle in the other universes.
So why did you mention not violating known physical laws as a criterion for cryonics not being pseudoscience?
Seriously? Somebody claims they have invented a method to achieve nigh-immortality, except they can't demonstrate that it works right now, and it's success conjunctively depends on a large number of highly questionable assumptions, and people with relevant domain expertise either ignore it or actively distance themselves from it.
I wonder what the relevant null hypothesis might be...
You mean Fermi estimates, and they don't work by pulling numbers out of your hat as you seem to be doing here.
I've read the introduction of the first one. It seems that the author is taking the Hamilton-Jacobi equation, adding a special extra term (the "quantum potential") and massaging it to get the Schrödinger equation.
That's doesn't strike me as particularly surprising, since it is well known that the Schrödinger equation is mathematically similar to the Hamilton-Jacobi equation. The "Hamiltonian operator" in the Schrödinger equation is called that way for a reason, and the Schrödinger equation converges to the Hamilton-Jacobi equation in the classical limit.
Huh, I've seen something vaguely similar in a physics textbook: the authors "derive" the Schrodinger equation by describing the properties that an equation has to have in order to describe an object (such as a single photon) that "interferes with itself" in the double slit experiment. Another textbook I've read simply says that "derivations" of the Schrodinger equation are basically bogus; the Schrodinger equation is an empirical formula that is chosen because it matches observations, and doesn't actually have any more justification than that.
The best discussion you are likely to find is in Ballentine. If you accept (empirically) Galilean invariance, the STRUCTURE of the Schroedinger equation falls out of group representation theory quite naturally.
The actual specifics of a problem involved picking a potential to use in the problem, and this is empirical. So if you ask the question: What equation does an electron in an atom obey? That is empirical.
If you ask: Given Galilean invariance and a 1/r potential, what equation does an electron in an atom obey? This doesn't need any more empirics.
And assuming Lorentz invariance gives you the Dirac equation, right?
Sadly, with lorentz invariance things get quite a bit more complicated. Adding in Lorentz invariance forces you to deal more directly with spin (and lets you prove spin-statisics), so you end up with the Klein-Gordon equation for spin 0, the Dirac equation for spin 1/2, and variants of the Maxwell equations for spin 1.
But you also get weird "paradoxical" effects trying to interpret the results of those equations along the lines of non-relativistic quantum, so you are forced to push towards full field theory.