Is there anything in the Universe that is not fundamentally made up of matter?

[Amazed]

Is there anything in the Universe that is not fundamentally made up of matter?

 

[Hornbein]

Electromagnetic radiation has no rest mass so it is not matter. It does however attract things gravitationally to a small degree, and is produced by matter.

 

[martinbn]

It depends on your definition of matter. If by matter you mean anything that can interact, then no, there isn't anything that isn't matter. If your definition is more restrictive, like the one used in post 2, then yes, there things that are not matter.

 

[DaveC426913]

Gravity, AKA spacetime curvature, is a thing in the universe, but it is not - itself - matter.

But the bigger, easier answer is - as others have pointed out - electromagnetic radiation.

 

[Amazed]

Electromagnetic radiation has no rest mass so it is not matter. It does however attract things gravitationally to a small degree, and is produced by matter.

When you say that electromagnetic radiation is produced by matter, then could this also be interpreted as being fundamentally made up of, or made by, matter?

 

[Amazed]

It depends on your definition of matter. If by matter you mean anything that can interact, then no, there isn't anything that isn't matter. If your definition is more restrictive, like the one used in post 2, then yes, there things that are not matter.

How do you or the people in a physics forum define the word 'matter'?

If electromagnetic radiation can attract things, then it can interact, so what do you mean by the definition in post 2 is a thing that is not matter?

 

[Amazed]

Three people have said that there are things that are not matter.

I asked are there things that are not fundamentally made up of matter, but maybe a better question would be is there any thing that is not fundamentally made up by matter?

Is gravity and/or electromagnetic radiation fundamentally made up by matter?

 

[Hill]

Three people have said that there are things that are not matter.

I asked are there things that are not fundamentally made up of matter, but maybe a better question would be is there any thing that is not fundamentally made up by matter?

Is gravity and/or electromagnetic radiation fundamentally made up by matter?

According to this definition, gravity and EM radiation are not matter.

 

[DaveC426913]

While not definitive, one might make a good start by grouping all things into either fermions or bosons.

Fermions obey the Pauli Exclusion Principle - they take up space - as matter does. It is possible to fill. a box with fermions until no more can be added.

Bosons do not obey PEP - they do not take up space - eg. photons. You can fill a box with photons and it will never get full.

 

[Borek]

Bosons do not obey PEP - they do not take up space

So helium-4 atom doesn't occupy space?

 

[DaveC426913]

So helium-4 atom doesn't occupy space?

Well, now I'm confused.

Bosons do not obey PEP.
He⁴ is bosonic.
Therefore He⁴ does not obey PEP.
Checks out.

I guess not obeying PEP does not automatically mean a particle does not take up space.

 

[PeroK]

Is there anything in the Universe that is not fundamentally made up of matter?

There is matter, antimatter, radiation, possibly dark matter, possibly dark energy, spacetime (if you count that as something). Anything else?

 

[robphy]

In General Relativity, the Einstein field equations read $G_{ab}=\kappa T_{ab}$,
where $T_{ab}$ is the stress-tensor, where all forms of "matter" go,
including the perfect-fluid photon gas

https://en.wikipedia.org/wiki/Perfect_fluid#Cosmology_and_astrophysics
The case where p=0 describes a dust solution. When p=ρ_m c2^/3, it describes a photon gas (radiation).

So, by this definition, light and electromagnetic radiation count as "matter".

 

[Ibix]

So, we're concluding that the answer is either yes or no, depending on what you include in the definition of the word "matter".

 

[PeroK]

So, we're concluding that the answer is either yes or no, depending on what you include in the definition of the word "matter".

It seems to me a bit like saying all the people in the world are men, if we count women and children as part of "mankind".

 

[Ibix]

It seems to me a bit like saying all the people in the world are men, if we count women and children as part of "mankind".

I'm torn between a line about "doesn't matter" and quoting Neil Armstrong.

 

[javisot]

So, we're concluding that the answer is either yes or no, depending on what you include in the definition of the word "matter".

1. Matter can be represented as a certain amount of energy.

2. It occupies space.

3. It can be approximated as a quantum system.

4. It can physically interact with something in some way.

5. It possesses some measurable property.

6. It can change state or form.

7. It has inertia.

Can we think of any other qualities or correct any of the ones mentioned?