Not all laws have "Law" in their titles either.
That was kind of my point. Back when science was mostly dominated by figuring out how things moved and why (back when all they had was the un-cool name "mechanics" where today we have the way cooler "dynamical systems"), things tended to be called "laws" and were usually either actual laws of motion, or laws describing how something like gravity or mass or whatever was involved in motion. As the sciences became less and less lumped under "philosophy" (or natural philosophy) and became increasingly distinct and increasingly numerous disciplines, we can find less and less borrowing from the language of classical mechanics. Things stopped being called "laws" as this stopped having much in the way of meaning anymore (after all, again most of the "laws" refer to are really just useful approximations, and aren't really "laws" in the classical sense at all). What used to be considered "laws" described rather specific characteristics (or properties, or principles) of mechanics, which were supposed to be at least nearly universally applicable in some sense. What the sciences tend to have now are too complex to create anything which is supposed to be as precise as classical "laws" yet can be generalized to describe observed dynamics in systems of pebbles to systems of planets. The more one can generalize some equation to diverse systems, the more likely it is to be a rough approximation and/or already a classical law.
Einstein's field equasions don't have the word "law" in them, yet they are considered a law in the scientific sense.
But compare the reduction of Einstein's equations into a more compact form to a classical law:
Gab =
8πGTab
where I can certainly "unpack" these into a system of nonlinear partial differential equations for some spacetime metric
gab, but the equation itself is a description of spacetime evolution itself. It also has more than one solution, some of which violate rather fundamental "laws" of physics. And finally, it is at the moment rather at odds with quantum mechanics and quantum theory in general.
So instead of a classical law which relates gravity to diverse systems, I have an equation which models spacetime itself, and which is only a first-order system (and thus is really only a description of spacetime evolution if I use it to as a means to supply constraints for what then becomes a second-order problem with given initial conditions). I also have more than a few problems using it in practice locally or generically, and finally it stands in contradiction (with no current method to resolve) to the
other single most successful theory of physics (quantum theory).
And within many sciences, there is nothing which even has something with similar (or less) problems but also the specificity and generalizable nature of Einstein's field equations. Meanwhile, we continue to call "laws" those things we
know are false.
Is it possible that while other sciences did initially start to imitate the use of language in mechanics (i.e., call things "law") this term is no longer clear, and furthermore no longer possible to use in the way that it was classically?
However the Planck-Einstein law does have "law" in it.
I'm not used to seeing it called a law, but I'm sure you're right that it is. However, once again this is the end of classical physics we're talking about. Einstein's use of Planck's constant contradicted previous experiments with light, and while it explained the photoelectric effect, it did so by saying light is made up of quantifiable (localized) "packets" of light-energy, which is neither true nor is Einstein's equation used anymore.
Perhaps it's simply a matter of taste.
As for age, there have been several biological laws that have been discovered during the mid to late 20th century. Especially as technology has allowed for better investigation of genetics. In physics and chemistry most of the low hanging fruit has already been picked.
Maybe it's taste, or perhaps you hit on something with the "low hanging fruit" being picked, in that perhaps in biology there are more recent and perhaps as yet unknown analogues to classical laws (accurate, specific in some sense but quite generic in another, like Newton's laws of just about everything). I don't know. But again, you've made me curious.
Thank you!
