30 open questions in physics and astronomy

A friend of mine asked me if I thought there were actual open questions in physics, ones that individuals or small groups could make a contribution to (as opposed to things like the Higgs boson which require 4000 people and billions of dollars to suss out). Here is a list I came up with. I don’t think it is definitive, and for all I know, some of these problems may no longer be open questions as of today, but I didn’t find anything better on the internets. It may be of interest to young researchers wishing to make a real contribution to human knowledge. Or maybe it’s just something to bullshit about.

Unlike other such lists, there are no silly cosmological or quantum gravitic types of questions on it. I think these are unanswerable questions, and not presently solvable by Baconian science. Essentially, such questions are metaphysical. They can’t presently be solved even in concept by making observations about reality. We’d still like to know the answers to such questions as how to unify gravity with the other forces, but it’s effectively a sort of mathematical philosophic enquiry, rather than normative science.

The other aspect of my “open questions” is they could conceivably be solved by an individual or a small team. I had to use my judgement on that, such as it is. I think these are all interesting and worthy mysteries; ones which could be of great import to the human race. I suppose they vary quite a bit in importance, but all of ’em are interesting.

1. High Tc superconductors: they cost nothing, and liquid nitrogen is cheap. Nobody knows how they work, or if they could make one at room temperature. The consequences would be tremendous if we could! IMO, every barnyard physicist who is worth two shits should have some perskovites and liquid nitrogen kicking around the lab, just for fiddlin’ with.
2. Turbulence and Navier-stokes is still little understood: this is pencil and paper physics which stumped Heisenberg. If you think liquids are important, this is huge.
3. Why is life chiral? When you make amino acids using chemistry, it isn’t chiral. How come life is chiral?
4. Quantum mechanics is still mysterious, particularly in the classical limit: pencil and paper contributions and relatively cheap (though carefully done) experiments are possible. This is one of the biggest open questions for it’s philosophical and technological (quantum computing?) implications.
5. Cosmic ray physics still has plenty of unusual phenomena. Detectors are cheap. You do have to wait for things to happen. What’s up with the giant cosmic rays for example?
6. Solid to glass phase transitions are poorly understood and very interesting.
7.   Fractional quantum Hall effect: simple and cheap experiments, and pencil and paper theory which could help us understand lots of other things in nature.
8.   Catalysis is fairly mysterious and potentially revolutionary for novel technologies. The models I have seen are pretty hand-wavey, and not very useful for inventing new catalysts or predicting the properties of old ones.
9.  Entropy and the arrow of time; this is at least as important as Ernst Mach’s philosophical ideas on relativistic things, which eventually helped lead to relativistic physics. Pencil and paper and thought experiments will suffice here. This is a very important philosophical question. Probably more important than understanding quantum mechanics.
10.   What is life? Nobody knows.
11.   How do brains work?
12.   Properties of metallic hydrogen -I think you can do these experiments in diamond anvils. Or you could send a lab to Jupiter.
13.   Is there a physics analogue for solving NP-hard problems? OK, this is cheating and stealing from computer science, but there may be physical algorithms you could use as proofs here, just like certain spectra could theoretically calculate Reimann’s Zeta. I’m not the only one to have looked in physical systems for answers here.
14.   Is there a knowable physics of granular materials? How do singing sands work?
15.   How does non-equilibrium thermodynamics work? We know there is order here; you can see the order with your eyes, but we don’t know what the rules are. This is potentially bigger than understanding quantum mechanics.
16.   Are there more new weird properties of matter? We keep discovering poorly understood stuff like high Tc superconductors and the fractional quantum Hall effect. Material science is vast and potentially technologically revolutionary.
17.   How does water work? The large heat capacity of water is an enormous physical mystery. Water should be vapor at STP. It ain’t.  People wave their hands and talk about hydrogen bonding, but hand waving doesn’t do much. This is also potentially huge. It’s freaking water: doesn’t get much cheaper than a jar of water.
18.   WTF is going on inside the earth? Whence comes the magnetic field? Why doesn’t Venus have one? Why is it so damn hot in there? Yes, I know there are theories: they don’t even pass a sniff test.
19.   What is the story with the Pioneer anomaly? If it’s accurate and not from something silly like an outgassing thumb print, this could throw everything we know about physics and astronomy into utter chaos. There is a way of answering this which would cost a half billion or so; shoot something into interstellar space on purpose and see what happens in 20-40 years. This is arguably far more important than anything in particle physics. The “flyby anomalies” turned out to be dipshits not understanding special relativity… I’m assuming that dipshits have done enough special relativity on Pioneer to rule this out. Otherwise: undergraduates: get to work! Edit add: I thought the flyby anomaly was resolved with SR, but googling further; it ain’t!
20. The atmosphere is filled with anomalies: ball lightning, sprites, ELVES, blue jets, TIGERs, green flashes & etc. I have a fat book by William Corliss catalogueing mysteries from the 60s; there are even more now.
21. There was a gamma ray burst where the high energy gamma rays got here before the low energy ones. Looks like highly anomalous physics.
22. GEO600 has produced some bizarro gravity results.
23. Corona physics makes no sense. Why is the corona hotter than the sun’s surface?
24. What are diffuse interstellar bands? Nobody has a clue as to what is absorbing light at those wavelengths, yet … I’m supposed to believe the standard model explains everything? Chyeah, right.
25. Is dark matter real, or is it the same thing that makes orbital mechanics fuck up? Something is weirding up the rotations of galaxies. I’m very tempted to put this in with the Pioneer anomaly and say, “gravity is largely untested using experiments; we should change this.”
26. Horizon problem;  why does the universe look homogeneous? It shouldn’t be.
27. For that matter, why is cosmic microwave background anisotropic, when everything else is isotropic?
28. What are magnetars?
29. Long delayed echos? This is a seemingly science fictional level of WTF. I recall some science fiction type speculated this was a sign of alien intelligence in the Solar System.
30. Why is there more matter than antimatter? I threw that one in for high energy types. You already have a result: if you’re so smart -figure it out.