Can't find it for the life of me... Describing a web comic vs actually posting it always feels like a flop, but...

Aliens abduct a physicist, who doesn't seem to give much of a damn about the abduction but is instead enthused to learn about the alien tech on board, so they give him a tour of the ship. They get to the power reactor and start dropping a bunch of sci-fi jumbo about "We harness dark matter to... (sci-fi Ruth Goldberg machine) ...and finally, we use the heat it generates to boil water and crank a turbine!!"

*Physicist drops to his knees in despair and let's out a dramatic 'noooooo!'

Paraphrasing heavily due to having shit memory. I thought it was a SMBC comic, but... /shrug.