Physics of the Observer - Cosmology: Panel discussion with Prof. Sean Carroll, Prof. Yasunori Nomura and Prof. Raphael Bousso.
Lots of interesting discussion. About half way through Sean Carroll asks for someone to stand up for "real objective reality". The participants are reluctant. I'd like to do that by arguing that a singular term "the universe" is inadequate as a term for all that is objectively real. When Raphael Bousso is talking about the universe being (using an abstract simile) like the inside of a box (from the perspective of an observer inside) as the universe expands faster than light at the abstract boundary can travel to the observer. This is clearly about products of EM processing that can be made when EM signals are received, what EM can be received and the relation between the potential observer and EM radiation distributed in the external environment. Which I would argue is not all that exists, only a part of it.
In the appendix of my recent essay contest entry I provided a classification of universe terms in the appendix, which i think is helpful:
Object universe: uni-temporal pattern and substance of all existence, at all scales. All extant actualization.
Uni-temporal Now: temporal expression of the Object universe, extant pattern and substance.
Material universe: those parts of the Object universe that are fermion particle differentiated existence or matter constituted of fermion particles and phenomena occurring that involve matter as particles, materials, objects, structures, systems or media. The Material universe can be considered a subset of the content of the Object universe.
The 'Visible universe' and 'Observable universe', as used in this essay, pertain to the EM of the Data pool of the Object universe. The data pool can be considered a sub set of the content of the Object universe.
Visible universe: visible to human's part of EM spectrum that is arriving at and receivable on Earth or location of space based receivers, (from which images can be generated.)
Observable universe: Primarily EM of those parts of the EM spectrum arriving at and detectable by human device's that can be received on Earth or their space based location, (from which images can be generated.)
The 2 definitions above can be expanded to include EM that is receivable and recoverable by humankind at locations outside of our solar system, when we have receiving devices there. And the observable universe could be extended to include other kinds of signal arriving and detectable, such as from gravitational waves.
Image universe: astronomic observatory outputs from processing of received signals.
Visible, Observable and Image universe relate to our relation to EM signals, whether through sense of sight or utilizing telescope technology.
It may be that in order to unite ideas about the universe where appropriate and to differentiate ideas where that is necessary, a clear classification of different terms is needed rather than trying to use one word "universe " for everything.