The SS Einstein is a spaceship derelict detected by Kryten while in artificial reality during "Back in the Red III". During this time, the former Starbug crew believed they had escaped imprisonment inside Red Dwarf by escaping in a Blue Midget shuttlecraft. Kryten was eager to get to the Einstein to get to more of a resource Blue Midget was critically low on--fabric softener. He was greatly concerned about everyone's linens getting all "bibiley bobbley".
The name "Einstein" caused the Cat to voice his memory that Albert Einstein was the "dude who discovered America". Rimmer than corrects him, stating that Einstein discovered the Theory of Relativity. The Cat responds by asking where it was discovered, "was it all fossilized in stuff?". Ignoring him, Rimmer attempts to explain the theory, but doesn't remember what it was, and neither does anyone else. Even the best Holly could manage was that it the Theory of Relativity is a theory you can only tell your relatives. After probing why he doesn't know what the theory, Holly explains the truth about was going on and the truth about the nanobots to prove his intelligence.