Adams is recognized in a conversation. Don't Panic In the series, Don't Panic is a phrase on the cover of The Hitchhiker's Guide to the Galaxy. The novel explains that this was partly because the device "looked insanely complicated" to operate, and partly to keep intergalactic travellers from panicking. "It is said that despite its many glaring (and occasionally fatal) inaccuracies, the Hitchhiker's Guide to the Galaxy itself has outsold the Encyclopedia Galactica because it is slightly cheaper, and because it has the words 'DON'T PANIC' in large, friendly letters on the cover." Arthur C. Clarke said Douglas Adams' use of "don't panic" was perhaps the best advice that could be given to humanity. British rock band Coldplay's debut album Parachutes contains a song called "Don’t Panic" in reference to the series. On 6 February 2018 SpaceX launched the Falcon Heavy rocket, carrying Elon Musk's Tesla Roadster which had "DON'T PANIC!" written on the screen on the dashboard as a reference to the series. Knowing where one's towel is Within the Hitchhiker's Guide to the Galaxy universe, towels are regarded as indispensable equipment for experienced travellers, since they can be put to a wide variety of uses. Consequently, a person who can quickly adapt to virtually any new situation is said to know where their towel is. The logic behind this statement is presented in chapter 3 of the first novel in the series thus: Adams got the idea for this phrase when he went travelling and found that his beach towel kept disappearing. In the 1985 book The Hitchhiker's Guide to the Galaxy -The Radio Scripts, his friends describe how he would always "mislay" his towel. On Towel Day, fans commemorate Adams by carrying towels with them. Mostly Harmless The only entry about Earth in the Guide used to be "Harmless", but Ford Prefect managed to change it a little before getting stuck on Earth. "Mostly Harmless" provoked a very upset reaction from Arthur when heard. Those two words are not what Ford submitted as a result of his researchmerely all that was left after his editors were done with it. The term is the title of the fifth book in the Hitchhiker "trilogy". Its popularity is such that it has become the definition of Earth in many standard works of sci-fi reference, like The Star Trek Encyclopedia. Additionally, "Harmless" and "Mostly Harmless" both feature as ranks in the