rod
"I enjoy using telescopes to observe. I am not sure how the wiki description of General Semantics fits with Galileo observations of Jupiter's moons or Kepler's planetary laws that were used in the geocentric vs. heliocentric debates in astronomy."
I must be careful not to digress
but I once enjoyed telescopic observation. At my advanced age I now prefer looking at the wonderful photographs such as of Io or Europa and relating those to the tiny dots of light I once saw (accompanying Ganymede and Calisto) through my 2 and a bit inch refractor.
Now, whilst I appreciate the part played by Jupiter's satellites in the expansion saga, I prefer the more philosophical topics relating to "our" Universe.
I was particularly interested in this which you posted:
"Cat you said "To me it is somehow connected with the Universe 'expanding' but galaxies staying the same "size".
This is a concern I have about the BB model. I find little reporting on galaxy size, i.e. angular size compared to redshift measurements." et seq
I have concerns also very much related to expansion.
If the Big Bang relies heavily (but not, of course, entirely) on running expansion backwards in time, how is it assumed to be linear or, in other words, how can it justifiably be extrapolated backwards to zero time ESPECIALLY when time is not supposed to be separate from spacetime? This is a particular hobbyhorse of mine. This seems to be the base of all sorts of 'silly' questions like What was before the BB? I rather favour a smooth transition to something like a "white hole" whatever that may be.
Sorry, just noticed more seems to have appeared in your previous post I thought I had read.