|Droplet of super fluid helium. |
Taken from talk by Adam Hokkanen.
physics and biology.
How are we meant to interpret analogies like this? Should we take them seriously and think that helium and starlings are just the same types of particles? Or should we see the similarity as just a loose rhetoric device? A way of getting the readers attention? These are the sorts of questions that are important if our aim is to apply mathematical models to make analogies. But the answer you get if you ask a theoretical physicists and mathematicians can vary greatly. They can also vary if you ask the same person on different days of the week.
Some physicists take these analogies very seriously indeed. I have been told on quite a few occasions that an experiment on ants or fish is unnecessary because it is "already proved by trivial symmetries in the system". Other times the analogies are made too loosely. No-one could be expected to believe that what is true for magnets is equally true for opinions about upcoming elections, yet this pretty much the assumption in many 'voter' models. The argument is sometimes made that the two systems have "deep parallels" and that the differences between iron filings and people are surface properties!
Other times, the argument is made that these analogies "capture the public's imagination" and are useful for communication.
I wouldn't argue that there is more than one correct way to make an analogy. However, there is a rule which I think should be followed and it is this:
Modelling analogies between a physical and biological systems should be based on empirical observations from both of the systems.
|Flow of starlings in a murmuration. |
From Cavagna & Giardina (2014)
This is when physical analogies are at there best. When we use mathematical tools, careful experiment and lateral thinking all mixed together.