\u201cIf at first an idea is not absurd,\u201d Albert Einstein said, \u201cthen there is no hope for it.\u201d Sometimes, however, absurd is just absurd \u2014 yet, even so, it\u2019s a fascinating slice of history\u2019s collective direction of curiosity and experimental innovation. 1. Soup-Cooling Spoons In this 1948 picture, a man is shown eating with a mechanical soup spoon designed to cool a bowl of scalding hot soup. Hans Reinhart \/ Getty Images 2. See-Through Boats This 1941 photo shows a model in a transparent "Lucite" rowboat, designed to see everything below the seat. Keystone \/ Getty Images 3. Automatic Tip Requesters In this 1955 picture, inventor Russell E. Oakes shows off his "automatic tip requester," which comprises an artificial hand and cashbox to be worn around the waist. A "No Sale" sign is displayed if a tip is not sufficient. Evans \/ Getty Images 4. Rocket-Propelled Bicycles In this 1931 picture, a German engineer prepares his rocket bicycle with 12 rockets mounted on the back wheel. Moments after this photo was made, the bicycle exploded. Fortunately the engineer was not seriously hurt. Topical Press Agency \/ Getty Images 5. Sunning Chairs In 1964, a 10-year-old named Marne Smith came up with an easy way to avoid a crick in your neck after lying outside for a tan. Doug Wilson \/ AP 6. Jetpacks Robert Courter soars through the air during a test of his flying jetpack in Ft. Myer, Virginia, on June 10, 1969. Bob Daugherty \/ AP 7. The Chain Smoker Model Frances Richards smokes a pack of cigarettes all on one cigarette holder. Jacobsen \/ Getty Images 8. The "Motorwheel" Swiss engineer M. Gerder is seen driving his "Motorwheel," a motorcycle with a wheel that runs on a rail placed inside a solid rubber tire. Photos \/ Getty Images 9. Glow-in-the-Dark Tires In 1961, the Goodyear illuminated tire was revealed to the public. The tire was made from a single piece of synthetic rubber that was brightly lit by bulbs mounted inside the wheel rim. Douglas Miller \/ Getty Images 10. Window Baby Cages In this June 1937 picture, a nanny is seen supervising a baby suspended in a wire cage attached to the outside of a high tenement block window. The cages were distributed to members of the Chelsea Baby Club who had no gardens and lived at the top of high buildings. Reg Speller \/ Getty Images 11. Pipe For Two Two men demonstrate a pipe called the "Double Ender" in New York, June 2, 1949. Ed Ford \/ AP 12. Suntan-Lotion Dispenser Model Betty Dutter demonstrates how the spray nozzle is held on the new "Sun-Tan Lotion Dispenser" at the Annual Vending Machine Convention in Chicago on Jan. 19, 1949. A dime could get you a 30-second spray job. Edward Kitch \/ AP 13. Bald-Head Polishers Ted Spence, an engineer at the Los Angeles Brush Manufacturing Corp., demonstrates the "Hairline Brush" on Jan. 12, 1950. The brush is constructed to fit a bald head's contour, with bristles for brushing hair and a felt pad to gently massage the scalp. Don Brinn \/ AP 14. Nuclear Bomb Shelters In this Sept. 12, 1958, picture, a bomb shelter is shown that can hold eight to twelve people and would be safe to within three-quarters of a mile of ground zero if a 20-megaton nuclear bomb were to be dropped. Dvn \/ AP 15. Vibrating Bras A model is seen trying on a spiral electric bra at the "20th International Show of Inventions" in Brussels on March 13, 1971. The bra claimed to develop and strengthen the bust and was designed to vibrate while the person wearing it was at work. Anonymous \/ AP Credits:\u00a0vintag.es Share this story on Facebook with your friends.