[bloopernova]

Would the universe in those other 2 older events have been 2 orders of magnitude smaller still? Have there been any estimates made for the sizes in each "event"?

Are there even more events further back, or is the next one after gravity the big bang?

What a fascinating subject, thank you for expanding my own little universe!

[ben_w]

I'm skim-reading on mobile right now, so here's some more information, but I didn't see anything about how much the universe expanded since 1 second after the big bang, which is the relevant number for the neutrino background:

https://en.wikipedia.org/wiki/Cosmic_neutrino_background

https://en.wikipedia.org/wiki/Neutrino_decoupling

and for gravity:

https://en.wikipedia.org/wiki/Gravitational_wave_background