Photographs by: Atholpady, Dreamstime (smell); Twixx, Dreamstime (homework); Dinarowe, Dreamstime (spotlight); Monkey Business Images (family); Wavebreakmediamicro, Dreamstime (sounds); Sebcz, Dreamstime (dust); Fotmen, iStockphoto (beach scene); Andrew_Mayovskyy, iStockphoto (winter scene); surpasspro, iStockphoto (breezy); jerbarber, iStockphoto (lightning); sandsun, iStockphoto (desert); mf-guddyx, iStockphoto (spinning ride); SelectStock, iStockphoto (fast coaster); mjbs, iStockphoto (loops on coaster); makluk, iStockphoto (roller coaster); RobertKovacs, iStockphoto (bumper cars); Kim Karpeles, Alamy Stock Photo (backward ride); PhotoEuphoria, iStockphoto (sweater); Ballun, iStockphoto (sunglasses); bonetta, iStockphoto (swimsuit); bonetta, iStockphoto (medicine); Edu_Oliveros, iStockphoto (headphones); Triton21, iStockphoto (raincoat); Zess77, iStockphoto (dove); Alexia_Khrushcheva, iStockphoto (horse); DeMoN89, iStockphoto (bear); MaggyMeyer, iStockphoto (lion); Alexandru-radu Borzea, Dreamstime (goldfish); Byrdyak, iStockphoto (rabbit); CagriOner, iStockphoto (all planetary symbols); NASA, JPL (Mars, Venus, Neptune, Jupiter); Reto Stakli, Nazmi El Saleous, and Marit Jentoft-Nilsen, NASA GSFC (Earth); NASA, JPL, Space Science Institute (Saturn); BrianAJackson, iStockphoto (holding magnet); GaryTalton, iStockphoto (melting); Oleg_Ivanov, iStockphoto (freezing); joshblake, iStockphoto (invisible); Anikasalsera, Dreamstime (leap); Bellevue, Dreamstime (electric bolts)