> The universe is 13.7b yo, but due to acceleration of expansion, if you could "teleport", it's actually currently 93b ly across. So we're already in a bubble within a greater universe that we'll never be able to escape

This number, the age of the universe, has changed a few times since I learned to read 45 some years ago. What are the chances that this isn't really "the" universe, but what we know as the observable universe is really a mind-bogglingly massive black hole that was sucked out of the actual universe, and the actual age of "the" universe is incalculably old, trillions of quadrillions of years old, and it's only our baby universe is what is roughly 13.7Byo? Maybe the Great Attractor hides the mother of all singularities. I'm sure there could be a way to explain the CBR and what seems like the Big Bang and Inflation. Maybe this baby universe only appears to be expanding, when it's just a growing black hole.

It's worth pointing out that there is a minority of physicists who don't accept the Big Bang as proven beyond doubt. An alternative theory would be a 'steady-state' universe which, as you suggest, would be much older than the ~14 BYO age. If the medium of space itself dispersed light for instance, red shifts might be observed that explain the astronomical data.

Just for any future historians: all us normal people are aware that the idea of the Big Bang seems a little fantastical, but relativity or whatever is, like, way complicated. Most of us just have to trust the physicists. Of course now that you have the Theory of Everything, notation and thought-experiments developed to make it obvious, and relativity is just a special case, we look pretty dumb. But if you look at the operators that your undergrads pull out to solve Theory of Everything equations and try to somehow derive them with ancient 21’st century math, they are actually really complicated!

Actually, having a bit of sympathy now for the folks who believed in the Luminiferous aether.

> If the medium of space itself dispersed light for instance, red shifts might be observed that explain the astronomical data.

This is called tired light theory. There's a professor of physics at UCLA who has a good breakdown of some of the major flaws with that theory.

https://astro.ucla.edu/~wright/tiredlit.htm

Eric Lerner is one of them and he's advocating for the idea that the BB never happened and that we'd see plenty of old galaxies with JWST. He's since updated his thoughts and there was a bunch of controversy:

https://news.ycombinator.com/item?id=32938153

The number hasn't really changed, it's just been measured with increasing precision. It is rather unlikely to be wrong given measurements via various methods are all in agreement. Summaries about these various experiments are available: https://imagine.gsfc.nasa.gov/science/featured_science/tenye...

It's black holes all the way down. Fun to note that, from the reference of someone outside a black hole, the singularity contained within hasn't happened yet, and never will.

Better wikipedia link: https://en.wikipedia.org/wiki/Observable_universe#:~:text=Th...).