Like multicore computer chips, Android smartphones, and Starbucks coffee, LCD TVs are getting cheaper—and bigger—all the time. Inevitably, your brother-in-law’s new 55-inch TV cost less than the 48-inch model you bought two years ago. Why? Science! See, flat-panel displays are made by machines that print arrays of circuits on sheets of glass and then slice those sheets into screens like high tech brownies. And since 1999, those machines have increased in size by 800 percent. Thus, the Law of Big Glass: The larger the glass printer, the cheaper—or bigger—the TV.