Science today, gone tomorrow

Christopher Ireland asked me a wonderful question a few days ago: “Of all the facts and principles that science currently believes to be true, which do you think are most likely to be disproved in the next 50-100 years?”

There is more up for grabs in the sciences than some people might think. Christopher explains why this matters:

“I'm interested because I believe social behaviors are strongly influenced by
our collective scientific beliefs. There's a lag time (a long one) while the
science filters down to the population, but once it becomes part of people's
general sense of reality, it changes their behavior in subtle, but pervasive
ways.”

Here are my guesses:

Brain function. There's a lot of work going on here, and it's amazing how little we know. fMRI data is just beginning to be integrated with static imaging, and the scale of analysis is large - patches of brain tissue centimeters across. As the resolution improves, a lot of old ideas will have to be thrown out; they may improve the standard "functional areas" analysis of where how information processing happens.

Cosmology. The standard model of cosmology is creaking, but nobody really knows what to replace it with. "Dark matter" is a symptom; it's essentially a fudge factor in the model invented to make the the universe expand at observed rates. I suspect we'll also see some change in more mundane fields like stellar and galactic models; they're constantly being stressed by new data. The Big Bang model could be discredited in a lot less than fifty years. Who knows, some people are even muttering that Newtonian mechanics is incorrect.

Climate chemistry. There's so much attention here, and there are so many layers of analysis involved (that is, from molecular chemistry to bulk transport at the order of kilometers), that I expect "facts" greenhouse mechanisms to be restated. It wouldn't surprise me at all if other chemicals beyond CO2 and methane turn out to be critical in global warming. I'm not saying that global warming will be found to be incorrect, just that the mechanisms we now assume to be true could well wrong.

Geology. Plate tectonics has stood the test of time but increasingly fine-grained new data could undermine the heuristics that are used to explain earthquakes. We know so little about the dynamics of the mantle, let alone the core, that we might have a very different view of crust activity in a hundred years.

Materials science. This is another multi-scale field, like climate. There is a lot that's not understood between the Angstrom scale of atoms, the nanoscale of new materials, and bulk behavior. It's not been a fashionable field, but it's quite possible that some basic rules of thumb, eg in tribology, will come to be rewritten.

Biological classification. We know almost nothing about bacteria, relative to their importance. For example, the human gut houses 10 to 100 trillion microbes from 500 to 1000 species - more than 10 times the number of cells that make up the human body. The current three domain classification of life (eukaryotes, bacteria and archaea) could well turn out to be wrong.

S., who’s a lapsed physicist just like me, adds these thoughts:

Nutrition - or, more generally, "how to be a fit person". The constant discovery of new trace substances (aspirin, omega-3s, etc.) that you need to be truly healthy suggests the kind of explosion of epicycles that precedes a paradigm shift. I anticipate the discovery that there are multiple different models of a healthy lifestyle, and the "eat fruit and vegetables and lean meat, drink exactly 4oz of red wine a day, and exercise 90 minutes a day" is only one of these. Your model may be a matter of choice, or may be ultimately constrained by ? gut bacteria, level of social interaction, mitochondrial DNA, level of something in the womb, aspect of Saturn at your time of conception...

Quantum mechanics - your basic Schrödinger equation. This is a bit of a cheat on my part because nobody understands it. However, there's a swirl of ideas around the arrow of time, the classical limit of quantum mechanics, and Bell's inequality crying out for a major advance. Were I cleverer, this is what I would be working on.