What exactly is the intersection of Physics and Philosophy?

Question

I've asked a number of physics questions in philosophy, none of which included equations, and are determined by the larger, and as far as I can see philosophical questions about the natural world; traditionally, ie in Maxwells time, it would be called Natural Philosophy.

Qustions for example on Entropy, disorder, time and space. For example this question on entropy at time close to the Big Bang, or this one about the direction of time.

Yet people often attack these questions as not belonging to Philosophy

A quick perusal of the SEP shows that there are many topics that it covers; for example:

1. Action at a distance in Quantum Mechanics

2. Being and Becoming in Modern Physics

3. Boltzmans work in Statistical Physics

4. Quantum Approaches to Consciousness

5. The role of Decoherence in Quantum Mechanics

So what gives; why the 'directives' to post questions which are aimed towards the more philosophical end of physics being solely confined to physics? And how does one determine the distinction, given that there is one.

Answer 1

Taking as one example your question about Entropy at the moment of the Big Bang (which I was one of the five who voted to close):

1. It seemed that the process for coming up with an answer is totally in the realm of mathematics/physics. While your question did not include an equation, I would imagine an answer to that should include an equation (or describe what an equation might look like).

2. I've seen other questions that fall into the gray-area in which philosophers had once-upon-a-time considered the question but the question had been resolved by modern science. In the case of this particular question, it seemed like you were using ideas squarely in the realm of modern physics (entropy, black holes, singularity).

So, that's why I voted to close it. As always, I'd prefer not to close questions, and if I misunderstood the question's intent, I would be happy to change my vote.

Your point about Being and Becoming is an interesting one. That article points to several interesting philosophical questions and consequences of physics, but notice that it doesn't ask any quantifiable questions about things analogous to what was the entropy at the Big Bang.

Answer 2

The basic framework I use to determine topicality is essentially about whether it's something you're encountering that is plainly arising organically from an encounter with philosophical study, reading and analysis. I've tried to articulate it in that long thing I wrote about "we are not philosophers, people". The point is that it has to be about some obstruction or vortex that is preventing your navigation through philosophy.

The issue then is that the question-problem has to be an encounter you have while trying to undertake the study of philosophy. But this is actually a philosophical question in itself -- I mean, whether philosophy has any content of its own, or is rather a process of refactoring and constructing higher-order "algebras" for everything "else". At any rate it raises the hairy old question of what philosophy "is".

I'm tempted here to point to Deleuze and Guattari's insistence that philosophy is a creative activity, that it creates concepts. Finally maybe even that philosophy cannot be undertaken even as study without the reproduction and permutation of conceptual personae. Creating concepts through pure variances is how philosophy thinks; where mathematicians and sciences think in terms of functions made up from variables; and artists and writers think, again just as much as philosophy and science, but in terms of affects: colors, sounds, textures in composition.

And all this is maybe to say: while philosophy and science may appear to be great enemies, science is maybe the greatest ally to philosophy in the war against received notions, popular perception, religious dogma and so on. There is something similar to be said for science and art. And in fact all this points to the great "outside" that each of these disciplines face, and the universal shadow that falls across them all -- cast by the glare of the future, by a people to come and an imageless thinking to come. Nietzsche dreamed of the reunification of science and art/philosophy at long last; once both had become "profound" enough for the transformation.

I mean, look -- I think we have the merest glimmers of this sort of thing today; but it's enough for me not to wish to draw particularly granular boundaries. Again the basic framework being something like: does the question specifically refer to an organic encounter with a thinker, work or idea in your study of philosophy? If not perhaps it isn't really our question after all -- though if you do happen to find a line of investigation that does connect back to problems you're working through in your philosophical study, that seems at least plausibly topical again.

Answer 3

I'm a big fan of quoting Wikipedia to show my ignorance before making an answer:

Philosophy is the study of general and fundamental problems, such as those connected with reality, existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational argument. In more casual speech, by extension, "philosophy" can refer to "the most basic beliefs, concepts, and attitudes of an individual or group".

I think the key to any physics based questions being deemed "philosophical" would be an attempt to turn them into fundamental problems. This of course is a loaded phrase, but I have an opinion on how it should be resolved: a physics based philosophy question should be rejected if it does not attempt to reach beyond the confines of its science.

A question about what was the entropy before the big bang, to take an example from James Kingsbery's answer, is purely entrapped in physics. It is setting up a purely numerical request based on the "laws" of science (perhaps better phrased as "scientific models"). Its ability to accept or reject answers is wholeheartedly based on science. This makes it a pure physics question in my mind.

This question could be rephrased to add a philosophical bent by trying to add an attempt to scratch the edges of science. For instance:

• ... is such a number meaningful?
• ... are there any ethical implications of a non-zero entropy at the big bang?
• ... can any idealist models of the universe be rejected by studying this number?
• ... how could we categorize universes by their entropy at their onset?
• ... how would science have to change if the entropy was 0 and yet we believe we exist?
• ... Is science in a position to even discuss the concept of 'entropy of the big bang'?

Any of these extensions would drive the question into the land of philosophy in my mind. Without them, it is merely in the world of science... which is a very important world to us, but it doesn't seek to go any more fundamental than science already has.