Thursday, April 19, 2007
chemistry is physics
I haven't posted on here in more than a month, but that's because I didn't think anything particularly interesting was going on in physics. Now there is.
I remembered this article and realized that the word "stupid" is loaded and inaccurate, but there are many other things in the article that are true. Are physicists unable to observe complexity, if complexity even exists (or is another loaded word)?
The tone of this article suggests that physics might be an "easy way out", to avoid seemingly more challenging problems. Umm... physics is not the easy way out; it never has been. It's actually the hardest way out.
What Prof. Rancourt probably meant to say was that physicists spend too much time on very complicated problems, causing them not to be able to solve easier ones. I know a lot of mathematically gifted people who have to constantly double-check their arithmetic, because it's the arithmetic (not the calculus or higher-level math) that they might mess up. I've had a lot of experience with that in every physics course I've taken here. It's not the professors' faults; it's just that really smart people make a ton of errors (particularly in arithmetic)!
To circumvent that difficulty- if I ever become a professor- I want to know absolutely everything that I will teach the students before I teach the first class in a course. I don't want to make those errors, or try to remember what the form of such-and-such wavefunction is. I don't want to write a textbook and then clean up my own mess by writing a 40-page "errata" appendix.
This symptom of physicists and other mathematically-inclined people has led some physics departments to offer "more practical" courses like Physics for Future Presidents. You don't have to know what a Green's function is; you just have to know how to calculate square roots. No calculus or even algebra is assumed.
Why do we need courses like this? I don't know, but if you can offer the correct answer, I'll nominate you for the Nobel Prize (assuming I ever get to do that).
This disease of being unable to do "easier" calculations has led some physicists into the dark realms of anti-string theory propaganda and "stop global warming" thoughts. In trying to uncover the ultimate secrets of the universe, you're glossing over the more obvious truths, e.g.:
1. Global warming on a macroscopic scale is a myth.
2. The anthropic principle is a sensible addition to any grand unified theory.
3. String theory is the best candidate for a GUT.
4. In order for there to be a scientific consensus, 100% of scientists have to agree on something. Not 80% or whatever the politricks claim the global warming consensus is.
5. Climatology and LQG are two fields of science that started out attractive but rapidly turned ugly (well, climatology is far worse). At least LQG is based on quantum theory, whereas climatology is hardly better than alchemy.
The point is that even physicists are being seduced by bad ideas. Some of them ignore the more obvious facets of reality.
I think physicists should be required to take more biology and chemistry than they usually have to. Not because biology and chemistry will get you closer to the GUT (they don't) but because they're not so abstract. Physicists should know how chemists use simpler approximations to solve "more complicated" problems, e.g. atoms with atomic number Z > 1. Solving the helium atom using perturbation theory/ the variational method can get awfully tedious, unless you use chemistry.
To study covalent bonding in the hydrogen molecule ion (which isn't "complex" at all) you have to diagonalize the Hamiltonian matrix with components <1|h|1>, <1|h|2>, etc. (the kets can be in an n-dimensional basis, although typically you'll just use 2 and create a 2x2 matrix). The elements <1|2> and <2|1> do not give 0, so you end up with a matrix that can't be diagonalized very easily. After a lot of handwaving (and only then) you end up with energy eigenvalues (H11 plus/minus H12)/[1 plus/minus <1|2>]. Even a relatively simple problem like that takes a long time to solve, particularly if you're using a 5-dimensional basis to get a 5x5 matrix, for example.
I just think physicists would do better if they knew easier methods. Solving problems the ridiculously hard way is "the trouble with physics." ¶ 8:08 PM
I remembered this article and realized that the word "stupid" is loaded and inaccurate, but there are many other things in the article that are true. Are physicists unable to observe complexity, if complexity even exists (or is another loaded word)?
The tone of this article suggests that physics might be an "easy way out", to avoid seemingly more challenging problems. Umm... physics is not the easy way out; it never has been. It's actually the hardest way out.
What Prof. Rancourt probably meant to say was that physicists spend too much time on very complicated problems, causing them not to be able to solve easier ones. I know a lot of mathematically gifted people who have to constantly double-check their arithmetic, because it's the arithmetic (not the calculus or higher-level math) that they might mess up. I've had a lot of experience with that in every physics course I've taken here. It's not the professors' faults; it's just that really smart people make a ton of errors (particularly in arithmetic)!
To circumvent that difficulty- if I ever become a professor- I want to know absolutely everything that I will teach the students before I teach the first class in a course. I don't want to make those errors, or try to remember what the form of such-and-such wavefunction is. I don't want to write a textbook and then clean up my own mess by writing a 40-page "errata" appendix.
This symptom of physicists and other mathematically-inclined people has led some physics departments to offer "more practical" courses like Physics for Future Presidents. You don't have to know what a Green's function is; you just have to know how to calculate square roots. No calculus or even algebra is assumed.
Why do we need courses like this? I don't know, but if you can offer the correct answer, I'll nominate you for the Nobel Prize (assuming I ever get to do that).
This disease of being unable to do "easier" calculations has led some physicists into the dark realms of anti-string theory propaganda and "stop global warming" thoughts. In trying to uncover the ultimate secrets of the universe, you're glossing over the more obvious truths, e.g.:
1. Global warming on a macroscopic scale is a myth.
2. The anthropic principle is a sensible addition to any grand unified theory.
3. String theory is the best candidate for a GUT.
4. In order for there to be a scientific consensus, 100% of scientists have to agree on something. Not 80% or whatever the politricks claim the global warming consensus is.
5. Climatology and LQG are two fields of science that started out attractive but rapidly turned ugly (well, climatology is far worse). At least LQG is based on quantum theory, whereas climatology is hardly better than alchemy.
The point is that even physicists are being seduced by bad ideas. Some of them ignore the more obvious facets of reality.
I think physicists should be required to take more biology and chemistry than they usually have to. Not because biology and chemistry will get you closer to the GUT (they don't) but because they're not so abstract. Physicists should know how chemists use simpler approximations to solve "more complicated" problems, e.g. atoms with atomic number Z > 1. Solving the helium atom using perturbation theory/ the variational method can get awfully tedious, unless you use chemistry.
To study covalent bonding in the hydrogen molecule ion (which isn't "complex" at all) you have to diagonalize the Hamiltonian matrix with components <1|h|1>, <1|h|2>, etc. (the kets can be in an n-dimensional basis, although typically you'll just use 2 and create a 2x2 matrix). The elements <1|2> and <2|1> do not give 0, so you end up with a matrix that can't be diagonalized very easily. After a lot of handwaving (and only then) you end up with energy eigenvalues (H11 plus/minus H12)/[1 plus/minus <1|2>]. Even a relatively simple problem like that takes a long time to solve, particularly if you're using a 5-dimensional basis to get a 5x5 matrix, for example.
I just think physicists would do better if they knew easier methods. Solving problems the ridiculously hard way is "the trouble with physics." ¶ 8:08 PM
