Next in line of questions from readers, we have tbell with:
Since science is a self-correcting process (maybe only at a statistical level, not necessarily an individual level), it would be cool if you would relate the last time you were seriously wrong about some aspect of science or research, and how you altered your thinking as a consequence.
This is kind of a tough one to answer, because I’m an experimentalist. Most of the mistakes I make in the process of research are problems of a technical nature, like “I totally thought that would work, but the impedance of the vacuum feed-throughs was too high,” or “I didn’t realize that water cooling this system was going to be such a gigantic pain in the ass, but I’m stuck with this now.” The alteration in thinking required to deal with that sort of thing is pretty trivial, and not remotely philosophical in nature, so it doesn’t feel like a real answer to the question.
The most spectacular research failure I’ve had recently was a few summers ago, when I had a student working on putting anti-reflection coatings on laser diodes. We were using an old vacuum evaporator system with a molybdenum “boat” that we ran a large current (~100 A) through in order to heat little glass beads to the point where some of the silicon dioxide would boil off and coat the laser mounted about the “boat.”
My summer student was working on this, and having trouble getting the vacuum down to the minimum pressure we were looking for. I wasn’t too sure about the vacuum gauge we were using, though, and after several passes through the obvious joints and seals with no change in the minimum pressure, I said “Go ahead and turn the current on. Even if the gauge is right, it won’t do anything too bad.”
This was a major mistake, because it turns out that when you heat molybdenum in an atmosphere containing oxygen (say, because you have an imperfect vacuum seal somewhere), you can form molybdenum tri-oxide, which melts at a much lower temperature than the pure metal. So, when my student cranked up the current, the “boat” glowed really brightly, then disintegrated. As a bonus, all the glass beads we had been trying to melt vaporized and underwent some sort of chemical reaction that put a thick layer of velvety black soot all over the inside of the bell jar.
So, you know, I won’t be doing that again. Unless for some reason I want smelly black soot all over something, anyway…
On a more philosophical level, I guess I would point to something I said in my summary post on Many-Worlds. Prior to researching it for the book, I had a kind of dim view of the many-worlds interpretation of quantum mechanics, which struck me as needlessly baroque. On reading more about the subject in the process of writing How to Teach Physics to Your Dog, though, I got a better appreciation of it. Looked at in the right way, it’s actually rather simple and elegant, particularly when you include decoherence. That doesn’t mean it’s right, and doesn’t make me a many-worlds partisan, but I do have a much higher opinion of it than I did previously.
Random note from an engineer to an experimentalist:
If you’re having trouble finding good vacuum pass-thru hardware, check out http://accuglassproducts.com. Where I work we use them whenever possible, and they’ve been great. They have even developed a number of new products specifically for us, which they typically add to their catalog.
Tercel – engineers tend to have much bigger budgets than experimentalists :).
cool! nothing ever blows up in the EEG lab.
I’m disappointed that Chad considers it a mistake to have taken a dim view of the MWI. There’s plenty of criticism out there, but I haven’t seen much mention of a point I’ve made here and there about the question of when the “split” occurs, if ever. I know, many say there never is a split and the WF continues to evolve according to the SE. (abbrs. outed on request.) Well, why doesn’t the state “appear” or come across in practice as we would expect a superposition to, why do we see one instead of the other? The original point (?) of MWI was to avoid the unobserved combined state by saying they parted ways in some sense, and came up with IMHO odd speculations about states of neurons not communicating (but even then, couldn’t we prove the superposition was still there in other ways?) Well let’s consider that as two versions of MWI, say MWIS (adding “split”) v. MWIC (adding “combined” or corporate, etc.)
Consider now how MWIS models the “split” using a MZ interferometer to test interference. Most attention focuses on the BS2 output which shows the interference pattern. The temptation is to say the split occurs at BS2, the recombiner, since the output causes a click at one detector channel or the other but not both. However, if measurement isn’t something special and superpositions slip away from each other upon some instigation or offering of alternatives (such as taking one path or the other), then the first beam splitter BS1 should lead to a split: one “world” where the photon WF took the lower leg and another world where it took the upper leg. Yes some will say there isn’t really a split, the states don’t interact/interfere – but then, there wouldn’t be interference at BS2! Some like Deutsch try to say the worlds do interfere, but then in what sense are they separate at all? And note with a clean MZ we have coherent interactions up until hitting the detectors.
You are so right with that one, you made me laugh hard. I’m also an experimentalist, and “this was way harder than I thought” is something I come across way too often, maybe second after “Why the hell is this not working?”
However, I also have moments like those in the original question, when I believe some measurement result is caused by a particular physical process, but further experiments show this is not the case. They are not profound changes in thinking, but mostly “I believed this variation in the oscillations was due to elasticity, but now it seems that heating is more important”.
I think that’s an example of the day to day self-corrections of science, and the reason why science works so well.