Visit Talkchess Forum to know more, there is where you will find some 3000 programmers.
This was all a scam.
Alpha played on 30 times bigger hardware than SF, 4TPUs vs 64 cores.
4TPUs is around 1000 cores or even more.
Alpha had simulated opening book, trained on countless top GM winning games.
SF had very little hash.
TC was fixed at 1 minute per move, which is again detrimental to SF, which has advanced time management.
TPUs lack the SMP inefficiencies with more cores, so the hardware advantage was even bigger.
Etc, etc., so basically, this was just a huge publicity stunt on the part of Google.
Currently, Alpha is around 2800 on single core, so 400 elos below SF, and will not advanced much in the future, as, from now on, it will need advanced evaluation it will not be able to discover.
Concerning the 4-hours issue, well, LOL, this was 48 hours ago, so now Alpha is at 5000 elo?