Definition of Universe requires clarification, to enable discussion

[Catastrophe]

I believe there is considerable difference still possible in what we understand by Universe, and this goes beyond what we understand by observable universes. We need to look at the "we".

I do believe that "all there is" itself requires clarification. What do we mean by this? Exclude "all we can imagine there is"

The definition offered by John Gribbin is worthy of acceptance, in my opinion.

"John Gribbin graduated with his bachelor's degree in physics from the University of Sussex in 1966. Gribbin then earned his Master of Science (MSc) degree in astronomy in 1967, also from the University of Sussex, and he earned his PhD in astrophysics from the University of Cambridge (1971)."
"An astrophysicist, and a visiting fellow in astronomy at the University of Sussex."

“The Universe is everything that we can see, and interact with, and detect with our instruments.”

I suggest that this is firmly rooted in science,

It has been suggested, in effect, that this is assumed to be the same as "all there is", but it is not.
Hopefully, all scientists will agree with Gribbin's definition, and (maybe grudgingly) that "all there is" is not sufficiently specific..
After all, it must be conceded that, in terms of what we can observe and measure, the concept of the Universe itself, together with its very origin, are firmly metaphysical rather than observable - and is science not based on observation? .

Please note that I am not attacking BBT, just pointing out what is, at present, beyond the understanding of science (e.g., t = 0).
(For those who do not know me, I have an Hons. B.Sc., and have edited and partly written a scientific book for Marcel Dekker, as well as having numerous granted U.S. and other patents. I have the greatest respect for genuine science.)

I therefore propose acceptance of: (perhaps consider "or" or "and/or" in place of "and"?)

“The Universe is everything that we can see, and interact with, and detect with our instruments.”

Cat

 

[COLGeek]

Does "metaphysical" in this sense simply mean unknown or undetected? Possibly even "assumed"?

 

[Greenlight]

according to your definition, Does Dark energy and Dark matter reside in the universe?
as they are not directly observed or measured, only their influence is indirectly.

or do they fall into the exclusion of what we imagine there is?

 

[Classical Motion]

Wow!!! I totally disagree. That definition is way to limiting. Way too restrictive.

The universe is a volume. And it should be defined as such. It’s not whats detectable.

It’s all and everything in that volume, detectable or not. And as time goes on and we improve the range of that volume, that universe increases.

The universe will grow with tech. And the entities in that volume will grow with tech.

I believe there is more undetectable matter, than detectable matter. And I refer to regular matter, not some inventive matter.

I’ll bet the undetectable rarefied matter is much, much more than detected matter.

This undetected matter is NOT gravitational matter.

And space is NOT an entity. It’s the lack of such. An emptiness. A void.

And when you figure out what light is, there is going to be a lot of red faces.

Light is not an EM wave. EM waves are angular. They do not propagate. An angular wave has to be cut, and propagated separately for propagation. Singular one half “wave” chunks. One radius pi chunk. 180 degree chunks. ½ period chunks. Half turn. One half twist chunks.

EM radiation is a quantum dynamic. Discreet periods of EM field.

Duty cycle shift, not Doppler wave shift. Light is chunky. A chunky shift.

 

[contrarian]

according to your definition, Does Dark energy and Dark matter reside in the universe?
as they are not directly observed or measured, only their influence is indirectly.

or do they fall into the exclusion of what we imagine there is?

Quarks are only "observed" by indirect evidence, so it seems that DM and DE are part of the observable universe, assuming all the data about their existence is correct.

Which brings the question - how hard core is the data for DM and DE? Are there any reasonable alternatives to explain the "gravitational impact of DM"? And now we see that the Hubble tension is stirring things up. Again, not sure what to make of it all........which is probably not an uncommon consideration.