Bob Garfield and Mike Vuolo discuss the energetic history of the word sleep.Lexicon Valley is brought to you by The Message, an original science fiction podcast from Panoply and GE Podcast Theater. All of Season 1 is available now, so listen and find out why a 70-year-old alien recording seems to be killing people. Search for The Message on iTunes.Join Slate Plus! Members get bonus segments, exclusive member-only podcasts, and more. Sign upfor a free trial today at www.slate.com/podcastsplus.Twitter: @lexiconvalleyFacebook: facebook.com/LexiconValleyEmail: lexiconvalley@slate.comLearn more about your ad choices. Visit megaphone.fm/adchoices