‘Fundamental’ is a prime example of what philosopher John Post (presumably following legal jargon) called an “accordion word”: highly flexible and capable of expanding or contracting depending on context.
Physicists (of a certain stripe) and many cosmologists will view their domain as fundamental, and one will often see the expression ‘fundamental physics’ to describe an actual subject area—the idea being that such practitioners are dealing in ‘compositional ultimates’ (the ‘building blocks’ of physical reality, in journalese).
This can be a very useful way of thinking about things in terms of scientific development, of course. Discovering that some area is ‘more fundamental’ than another allows one to make sense of the less fundamental area in a new way—most often by reducing the laws and parameters of one theory to those of another (and most often, with some simplification occurring in the process: one sees how complex variety can emerge from combinatorics of simples). One gets explanations and understanding. Puzzles are resolved. One can predict new things. One ‘goes beyond.’ One gets ‘to the bottom of things.’ Ultimately, what is fundamental will provide the answer to the question “what is the world really madeD. Rickles (B)
Unit for History and Philosophy of Science, University of Sydney, Sydney, Australia
e-mail: dean.rickles@sydney.edu.au
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A. Aguirre et al. (eds.), What is Fundamental?, The Frontiers Collection, https://doi.org/10.1007/978- 3- 030-11301- 8_5 of?” Indeed, ‘downwards’ is where we are quite naturally led, according to many, by asking for explanations of worldly phenomena.
In philosophy, of course, it is the job of metaphysics, and more specifically ontology, to figure out what is fundamental. The history of philosophy provides many responses: atoms and void, ONE, numbers, four elements, geometry, substrata, mindstuff (truly the funda-mentalists!), states-of-affairs, etc. Physics often informs (and perhaps corrects) these fundamental theories, for naturalists at least; but physics in this case is not considered to provide the most fundamental description of reality: it leaves too much out.
One can see this divergence quite clearly in Lawrence Krauss’ book, A Universe From Nothing: Why There Is Something Rather Than Nothing (Atria Books, 2013)—attempting to explain everything (reality simpliciter) from current theories of physics alone—and the subsequent philosophical backlash against this claim (e.g. by David Albert in his New York Times review of Krauss’ book). Krauss argues that quantum fields and the vacuum are all one needs to explain the genesis and structure of every other thing. Albert strongly disagrees, and seeks ‘deeper’ (read more fundamental) explanations for existence than Krauss cares to bother with: for example, where do those quantum fields and the quantum vacuum come from? Where did the laws come from? One ends up using as explanatory fodder what is itself in need of explanation. As Albert puts it (usefully expressing for us the fundamentalist intuition en route):It happens that ever since the scientific revolution of the 17th century, what physics has given us in the way of candidates for the fundamental laws of nature have as a general rule simply taken it for granted that there is, at the bottom of everything, some basic, elementary, eternally persisting, concrete, physical stuff. Newton, for example, took that elementary stuff to consist of material particles. And physicists at the end of the 19th century took that elementary stuff to consist of both material particles and electromagnetic fields. And soon. And what the fundamental laws of nature are about, and all the fundamental laws of nature are about, and all there is for the fundamental laws of nature to be about, insofar as physics has ever been able to imagine, is how that elementary stuff is arranged. The fundamental laws of nature generally take the form of rules concerning which arrangements of that stuff are physically possible and which aren’t, or rules connecting the arrangements of that elementary stuff at later times to its arrangement at earlier times, or something like that.
But the laws have no bearing whatsoever on questions of where the elementary stuff came from, or of why the world should have consisted of the particular elementary stuff it does, as opposed to something else, or to nothing at all. (Albert, ‘On the Origin of Everything,’ March 23, 2012, New York Times)Fundamental in physics is not necessarily fundamental in philosophy, though one hopes for some continuity and coherence—and ultimately we might hope for total harmonisation. Fundamental in physics usually means higher energies and smaller scales, and less complexity (the most basic ‘simples,’ with no complexity at all). Not necessarily so in philosophy—and, as we will see, it is not really demanded by physics either, with several alternative directions. In each case, however, we speak of fundamentality in relation to other things through some form of dependence: the fundamental stuff is the sine qua non stuff.
The matter is not idle. Often, we find that funding decisions are made on the basis of ‘probing more fundamental layers of reality,’ with the assumption that this is clearly a good thing to do. For example, planning for the next phase of the LHC (the successor) is underway, and involves the idea that an accelerator three times larger (and seven times more powerful: 100 TeV) must be constructed [2]. Why? To probe deeper, to discover the ‘building blocks’: reality’s lego. To find, in this case, the ‘ultimate origins’ of elementary particles and spacetime. To find physics beyond the all-too- solidly-performing standard model. And then what? Do we suppose there will be no further pattern in the new data that requires yet deeper structure? Maybe. Maybe we will be forever ‘inward bound,’ to borrow Abraham Pais’ expression, peeling back the layers of the cosmic onion one after another without end. A philosopher might think, “why spend all that money on particle accelerators when you could pay just me to think, with no equipment other than my brain, to find out what is truly the fundamental structure of reality?” Regardless: how we define “fundamentality” matters.
We might think about defining it in a fairer and more inclusive manner.It is a widespread assumption that scientific progress means finding more basic constituents. It is certainly the received view. This is the common scientific meaning of fundamentality. It is a metaphysical assumption, and drives other assumptions, such as the idea that physics (elementary particle physics, or something like it) should (and can) furnish a complete account of the world: any and all things should be traceable back to the fundamental layer. This paper seeks to pull apart this assumption a little. I suggest that the physicist’s version of it might have something to do with the unreasonable effectiveness of mathematics in the description of laws. Ultimately, however, we find that fundamentalism (as a stance) does not demand the elementary particle physicist’s more micro-reductive approach, and there are several possible avenues one might take towards ‘being a fundamentalist’ in physics—some of these are well known, other perhaps not so.
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