Philosophy Discussion Forums

Steve3007 wrote: ↑September 27th, 2018, 9:57 am On the other hand, if metaphysics refers to concepts that have no connection, either directly or indirectly, with that which can be empirically observed, then physics has no use for it at all. It is a basic principle of physics (and science in general) that all propositions that purport to be about physics must be falsifiable/verifiable. In other words, it must be possible to describe an observation by which they can be tested.

I think even with this definition physics definitely includes metaphysics. Physicists and cosmologist with regularity explore ideas and even present theories and hypotheses that cannot be tested (now at least) empirically. Multiverses, for example. A time may come when such things can be tested, and it is useful to allow exploration of possible solutions to problems or anomolies even if these cannot be tested. But further I think any system will have assumptions, that is metaphysical ideas, built in that cannot be tests. i wish I was smart enough to bring in Gödel's theorum, but wihtout it I can still point to things like 'there are natural laws' 'everything is physical' which cannot be tested, at least not completely, but function as useful axioms for methodology or a conclusion based on incomplete evidence, but still useful, in the latter case. We can see this in the latter case where the category 'physical' has expanded to include 'things' that are completley unlike what would have been considered physical a couple of hundred years ago. The metaphysical category is expanding.

Karpel Tunnel wrote:I think even with this definition physics definitely includes metaphysics. Physicists and cosmologist with regularity explore ideas and even present theories and hypotheses that cannot be tested (now at least) empirically. Multiverses, for example.

I always take care to add "either directly or indirectly" and I sometimes add "either in principle or in practice" if I'm trying to be more precise. Many exotic concepts in physics may seem far removed from empirical observation, but that doesn't mean they have no connection to it at all. If a concept really doesn't have any possibility of ever being empirically verified/falsified at any point in the future, even in principle, then I would argue that it's not physics.

A time may come when such things can be tested, and it is useful to allow exploration of possible solutions to problems or anomolies even if these cannot be tested.

Yes, even if they can't be tested now. But it must be possible to describe a test in principle.

In particular: If a concept is defined such that it cannot be empirically test; if that property is part of its definition, then it is not physics.

Karpel Tunnel wrote:I can still point to things like 'there are natural laws' 'everything is physical' which cannot be tested, at least not completely, but function as useful axioms for methodology or a conclusion based on incomplete evidence, but still useful, in the latter case. We can see this in the latter case where the category 'physical' has expanded to include 'things' that are completley unlike what would have been considered physical a couple of hundred years ago.

I wouldn't class either of those two examples as laws of physics. But I wouldn't class them as axioms (self-evident truths) either.

"There are natural laws" is something that I would take to mean: "Our observations appear to follow patterns and those patterns appear to be useful in predicting future observations". That seems to me to be an empirical finding. It's something that we've learned to be true by experience. It's also arguable that if it weren't true (if Nature contained no patterns) then we wouldn't exist to find them.

"Everything is physical" depends on the definition of the word "physical". If it means "useful to physics" then maybe it's a tautology that translates to something like: "Everything of interest to physics is of interest to physics".

I think Planck time is the best starting point. From what I understand, one planck time is the highest resolution of time there is. Ther can be no events that are less than on planck time away. My understanding suggest that time passes one planck time at a time. time passes step by step, just like the second dial on a watch.

Frewah, some posit that reality is not granulated into Planck scale units but is 'gunk' (an official term) - see Consul's posts on this page in the Did the universe exist for ever or does it have a beginning? thread:

viewtopic.php?f=2&t=15546&start=299

It was an eye opener for me.