This is the tenth and final time that "Soft Kitty" is sung on this show, and the first time since The Recollection Dissipation (2017). Due to a lawsuit with the estate of the song's original composer, the song was only rarely heard since season 8, but the lawsuit has since been dropped.
The number on the scooter "626-789-3495" belongs to "Footprints on the Moon" which is the name of the band that Raj and Howard formed. You can see it on their Facebook page.
Amy is told that she could be the fourth woman in history to win the Nobel Prize for Physics. This was true at the time of broadcast: in 2020, astronomer Andrea M. Ghez became the actual fourth female Physics winner for the discovery of a supermassive compact object at the center of the galaxy.
Title reference: Amy is devastated that her outburst may have cost her a Nobel Prize, thereby depriving women of the chance to be inspired to go into science, so to relax, she goes to a sensory deprivation tank.
First appearance of Regina King outside of a flashback since her Oscar win for If Beale Street Could Talk (2018).