02 December 2005

Experimental validation!

Publications are all well and good, but you only really know that you've arrived in physics when you (and collaborators) propose some "arbitrarily accurate composite pulse scheme" and some respected experimentalists actually implement it! "Hot damn!" you say? And rightfully so, but let's see their conclusions.
The more complex B4 and P4 sequences, although theoretically superior, do not perform well in practice.
Oh well. It can be hard not to take this personally, and feel, after long days in front of the blackboard/web browser, that as a researcher and even a person, I am "in practice quite poor," "less useful than initially expected" and even "highly sensitive to the presence of off-resonance and phase errors." Happily, though, I'm still "theoretically superior"!

On the other hand, I did recently propose a "bubble-collapse" theory that explained the noise electric kettles made, and after some pointless arguing about rival theories, designed and carried out an experiment that proved I was right. (Stir it and the noise goes away!) Nevertheless, it's probably good that I've moved to CS.

Beware the Phase Errors, my son!
The sigma_X that bites, the sigma_Y's that catch!
Beware the Homogeneous Broadening, and shun
The Far-Off-Resonance Bandersnatch!

p.s. If you're on a job committee for one of my collaborators, I should point out that our sequences are just optimized for one kind of error, and of course by ignoring others the practical performance will be worse. Our paper should be thought of more as introducing new techniques/frameworks for producing composite pulses than as providing ready-made sequences that can be put into experiments. But please read it yourself if you're not sure.

4 comments:

mick said...

Hey, that's pretty damned cool. I wonder if anyone would ever try to test something I've written about... hmmm, I think I'd actively discourage anyone from trying any experiment I've proposed so far. I think the UN might see the subsequent abuses that would occur to grad students as a crime against humanity.

aram harrow said...

On a related note, I'm always vaguely shocked whenever one of my papers gets cited by someone outside the extended IBM family (Igor, Andreas, Debbie, etc..)+Patrick.

Thinking about this further led me to realize that if you have n papers, and each paper cites all of your previous papers, then your h-index will be at least n/2. Not that I would ever suggest this...

ahren said...

it sounds to me like the experimenters fucked up.

i feel like theoretical physics is like the nfl, where the kicker gets 100% of the blame for every missed field goal, even though probably 98% of missed kicks are mostly a result of a poor snap/hold.

the kicker is the theory-- flawlessly defining an inspiring method by which to make a ball go between two posts... and the holder/snapper are like the experimenters-- fumbling around and screwing up the machinery, so that the beauty of the kicker's inspiration is never fully expressed into the universe.

aram harrow said...

the problem is that usually they snap/hold the ball for a different kicker/theorist. or worse, they go for a running play!

so i have to at least act grateful for the opportunity to kick, at least for now...