Difficult Concepts (for me)

[chasmanian]

"What is testable is GR. Without a quantum gravity we have a well tested theory that is only testable back to a Planck time after a Big Bang or Big Crunch."
wow, awesome.

"Whether space NOW 13+ billion years after is infinite is testable assuming GR and the CMB observations. Given those assumptions and observations the odds are 2:1 that space is infinite. By reducing observational error one can get more definite about the test result."

hmmmmm
the sky's the limit? hahahaha

nFA, if you feel like it,
would you please elaborate on reducing observational error?
is it possible or likely?
how would it be accomplished?

[notFritzArgelander]

"What is testable is GR. Without a quantum gravity we have a well tested theory that is only testable back to a Planck time after a Big Bang or Big Crunch."
wow, awesome.

"Whether space NOW 13+ billion years after is infinite is testable assuming GR and the CMB observations. Given those assumptions and observations the odds are 2:1 that space is infinite. By reducing observational error one can get more definite about the test result."

hmmmmm
the sky's the limit? hahahaha

nFA, if you feel like it,
would you please elaborate on reducing observational error?
is it possible or likely?
how would it be accomplished?

There are two main approaches to reducing the observational errors.

First and most straight forward is simply the improvement of the technology of CMB observations. It’s going to happen in some decades.

The second one is to find connections between the parameters that can be determined from the CMB and other methods as well. This might happen sooner than decades. For instance the texture of the CMB fluctuations should be relatable to the texture of the mass fluctuations observable at later times by the JWST. This would provide more leverage to the problem than just beating current errors down with better technology.

[chasmanian]

thank you super much nFA.

[chasmanian]

nFA,

as for the infinity in singularities,
I am thinking that both actual and potential infinity proponents,
would see that as neither actual nor potential.

it just tells us that GR does not work there.
is that right?

[notFritzArgelander]

nFA,

as for the infinity in singularities,
I am thinking that both actual and potential infinity proponents,
would see that as neither actual nor potential.

it just tells us that GR does not work there.
is that right?

Indeed it says that GR fails at singularities.

[chasmanian]

thank you very much nFA!!