Total Perspective Vortex

The Total Perspective Vortex, in the fictional world of Douglas Adams' The Hitchhiker's Guide to the Galaxy, is the most horrible torture device a sentient being can be subjected to. Located on Frogstar World B and powered by a small piece of fairy cake[?], it is a device that shows its victims their place in perspective[?] to the universe, and forces them to realise how totally and utterly insignificant they are.

The machine was originally invented by one Trin Tragula in order to annoy his wife. Because she was forever nagging him for having no sense of proportion, he decided to invent something that would show her what having a sense of proportion really meant. Unfortunately the shock of being placed in the Vortex destroyed her brain, but Trin Tragula's grief was tempered by the knowledge that he had been right and she had been wrong. The Total Perspective Vortex had proved that in an infinite universe the one thing sentient life cannot afford to have is a sense of proportion.

Only Zaphod Beeblebrox is reported to have survived the Vortex unscathed (and to have eaten the small piece of fairy cake). This may be due to the fact that he has an ego the size of the universe, or more likely that the Vortex he entered was in fact a copy in an artificial universe that was specially created for his benefit, making him the most important being in it.