I’ve seen this video where GOOGOL gear is depicted (it takes 10100 years on reaching the final gear) but how many generations will it take? The 5th gear takes about 10 hours in real time, by the time the 10th one starts spinning (you’re probably already dead).
The entire thing consists of 100 gears. However, even if you record or livestream a video of the entire thing: would you still be alive by the time the final gear starts spinning? The common life span of a human is around 72-73 median but some can reach 100+ up to 125.
In 10^100 years the only matter remaining is iron and some of the last black holes
Maybe. That’s what we currently believe should happen based on our current understanding of the universe’s known systems and fundamental physics. Which has changed significantly even in the last 100 years, nevermind how it might change the next 10^100.
It is misguided hubris in the extreme to believe that our current understanding of literally anything, much less something as huge and unknowable as the entire universe is complete and perfectly accurate. There is no way to come to the conclusion that we therefore currently know everything that is going to eventually happen in the universe without a doubt. We only know what our current understanding tells us will happen. A reasonable person understands that in 100 years our current understanding at that time will probably tell us something slightly different, and it’s best to acknowledge that.