Title reference: Sheldon thinks of himself as a modern Tesla, and is shocked when his friends call him an Edison.
Raj claims that Thomas Edison electrocuted the elephant Topsy. Topsy was killed in 1903 and her electrocution was filmed by the Edison film company (see Electrocuting an Elephant (1903)), but contrary to popular belief, she was not electrocuted because Edison wanted to demonstrate the dangers of alternating current (the "war of the currents" has been settled in the 1890s) but because her owners wanted to get rid of her, as she had a reputation for being difficult and had killed a man. Thomas Edison does not seem to have even been present on Coney Island, where the electrocution took place, that day.
The documentary referenced during the episode is probably the History Channel's Edison vs Tesla (2015). Another possibility is The Current War (2017), but although it was released on several festivals in 2017, it didn't see a general release in the USA until 2019, two years after the episode is set. Also, this was a dramatized feature film, not a documentary.
Sheldon invents a a neutrino-based communication system. He may have gotten the idea from The Enemy (1989), where his friend (but currently enemy) Wil Wheaton as Wesley Crusher conceived of a neutrino probe to signal Geordi LaForge.
Barry Kripke (John Ross Bowie) and Colonel Williams (Dean Norris), who were last seen in season 10, make their first appearance in season 11.