I started working on this post a loooooong time ago -- back in February of this year, when dinosaurs roamed the earth. I wrote up about 4/5 of it, was called away, and forgot to ever return to it. So yes, the blog posts I'm linking to are several months out of date, and I'm sure the discussion progressed quite nicely without me. But it's not like this issue will go away anytime soon.
First salvo fired by Julianne Dalcanton of Cosmic Variance. She attacks a misconception in the physics community: if physics is actually difficult for you, if you're not Feynman-Einstein-Hawking smart, you are pretty much worthless as a physicist. You are only fit to do low-energy, experimental, or otherwise `lowly' work. You would be better off spending your time teaching more sections of freshman mechanics.
Apparently this misconception is unfortunately very widespread among physics people at all levels, and leads to talent drainage as people decide they just don't have what it takes, and head off to some easier field. The vast majority of useful physics work is done by people who aren't off-the-charts geniuses (and this is true to a lesser extent even of the revolutions that individual geniuses catalyze; Einstein was nothing like solely responsible for the theory of relativity). Physics is hard, and if it's difficult for you that doesn't mean you're stupid or unworthy. Welcome to scientific inquiry.
Score one for sanity. (Do yourself a service and go read the original entry; my summary doesn't nearly do it justice.)
Second salvo fired by Chad Orzel over at Uncertain Principles. He attacks the misconception that there is a Great Chain of Being in the physics department, and the more theoretical your work, the higher you rank. Low-energy experimentalists are right down there with biologists (gasp!). You're stupid if you have a hard time with algebraic topology, or if you spend a lot of time fine-tuning apparatus instead of grandly theorizing about the universe.
This misconception is also widespread. Supposedly, the farther removed your work is from `reality', the harder it is. As Orzel points out, a lot of the most difficult work is in experiment, where you HAVE to pay attention to reality. None of this "setting inconvenient constants equal to 1". A lot more of the most difficult work is in integrating theory with reality. Level of abstract or mathematical content (which does correlate with incomprehensibility) does not determine value; not even close. Also, what theorist could come up with this clever use of post-it notes?
[I'll add the following to Orzel's points: One of the things that a prof I've worked under likes about biology is that Experience Matters. This is true at all levels. It takes a fine hand, lots of practice, and an acquired intuition for how reagents/cells/tissues/animals behave, to do complicated procedures properly and get good results. And when you get curious results, it takes experience (and a good mental database of papers) to think of good reasons why that result happened, and especially to think of what followup experiments to do. It seems like this should be true of most experimental work, though I only have direct experience in cell-bio and linguistics.]
Score two for sanity. (Again, do yourself a service and go read the original entry.)
I will attempt to fire a third salvo, though (a) I'm not third, more like twentieth, especially if you count comments discussion and (b) I don't have enough experience for my contribution to be worthy of the title "salvo".
I declare that there is no Great Ladder of Scientists, going biologist <<< chemist <<< physicist <<< mathematician. Further, there is also no Great Ladder of Biologists, going ecology-level <<< organism-level <<< cell-level <<< molecular. Generally, height on these ladders is associated with abstraction, level/volume of math involved, and smallness of what you study. That, too, is plain wrong.
Sure, it's harder to visualize molecules bouncing around and reacting than it is to visualize zebras bouncing around and getting eaten by lions. That's not the point. Molecules may be smaller, but zebras, by virtue of being made of zillions of the most complex molecules in existence, are complicated. The bigger and more biological the entities you study, the more processes are going on at once. Molecular interactions are hard to model because we don't have an intuition for how things behave at that microscopic level (weirdly). Zebra interactions are hard to model because there are so many variables, and the same is true of organs, and tissues, and cells, and etc.
Also, it's often said that microscopic work is difficult because gut instincts are wrong. That's a fair point. Instincts aren't supposed to be 'right', they're supposed to keep you alive and breeding. And yes, it is difficult to imagine quantum particles going around doing their quantum thing, because "their quantum thing" is so at odds with our daily experience. But the same thing is true of molecular biology. If you think about proteins going around in a cell and reacting with each other, it's likely to play out like a stately dance in your mental theater. In reality, there's an awful lot of aimless random wandering, mistakes, and awkwardness between proteins. It's less of a symphony and more of an enthusiastic but unprofessional pub-session. In ecology or meteorology, gut instinct fails just because of the huge surfeit of variables and random factors. In cognitive science, gut instinct fails because we're not optimized to understand ourselves, and especially because everyone's used to computers, which don't work very much like brains. Etc, etc.....gut instinct fails for different reasons in different fields.
It's worth admitting that some sciences are younger than others, and the easy problems get solved first. The difficulty/scale of a field's "big problems" will be proportional to some function of how many scientist-hours have been poured into that field. But that doesn't mean new fields are inherently easier (or harder); it just means they're new. In several years they'll be at about the same level of difficulty as the fields people have been pursuing since they could walk.
The fourth salvo, "humanities people do not rank just below worms", is left as an exercise for the reader.
Here are the comments from the original LJ post.