Definition of physical

[robvalue]

This is something that's come up a few times now, and I'm not completely clear about it.

Is it correct to say that something being "physical", in scientific terms, is the same as saying it "exists"? Are these two terms exactly the same? I refer to literal existence, rather than abstract concepts which may or may not represent literally existent things.

If these two terms are not interchangeable, could someone please explain to me what the difference is? My first concern would be with "space", as in the space that is available for things to "exist in". Is the space itself physical? Does the space, or the potential it represents, "exist"?

Many thanks!

[ignoramus]

I'd agree with that. None sure at the quantum level though.

[robvalue]

OK cool, thanks

I'm trying to understand if the phrase "non-physical existence" is coherent. People peddle magic "supernatural" entities of course. But if physical simply means existant, then these magical entities are also physical; or else they don't exist.

[ignoramus]

I don't think so. It works one way. Physical = exists, non physical entity = ?

Other than abstract thoughts, do we know of any natural phenomena which exists without taking up spacetime?
I can't think of any.

EDIT: Not sure about potential energies?

[Silver]

https://youtu.be/vWz9VN40nCA

Sorry, had to do it. xD

[Thumpalumpacus]

I think of "physical" as "that which has material form."

[Regina]

I'd say "physical" is something tangible that you can feel, as opposed to the intangible that isn't so easily sensed.

[robvalue]

OK, thanks guys

Yes, I can see it would be reasonable to say that which is physical exists. It's made up of something you can meausure in some way, and which can have an impact on other things.

If someone wants to make the case that something non-physical can or does exist, then I think it's up to them to say:

(A) What does this even mean? In what way does it exist? How is it different from something that doesn't exit?

(B) How can you possibly ever determine that there is such a thing, if you have no way of detecting it?

If science does already acknowledge some sort of non-physical (literal) existence, I'd be very interested to know.

[ignoramus]

Even the cosmic background radiation from 14b years ago is detectable!
No god detected amongst it sadly!

Lucky for the theists the cheeky bugger lives outside of spacetime! He he ....... Not!

[ErGingerbreadMandude]

Hmm,Rob, do you think it would make sense if we called anything that can reflect light as "physical"?