My brother just switched from cigarettes to an e-cigarette that uses liquid nicotine. He claims his new habit is no worse than drinking two cups of coffee a day. Really?

There is an abundance of hard science showing that smoking cigarettes is deadly. But cut out the tobacco and the additives, and e-cigarettes are demonstrably less harmful than Camels. Ordinary smokes infamously contain a bevy of nasty ingredients—a little carcinogenic vinyl chloride or toxic arsenic, anyone?—whereas e-cigs employ relatively simple solutions of propylene glycol and nicotine. (Yes, ...

• The idea is a century old.
  As soon as Wilhelm Röntgen discovered radiation in 1895, scientists dreamed of using it to kill off pathogens hitching a ride on dinner. But actual experiments didn’t really get cooking until the 1950s, when the US Army used spent nuclear fuel rods to irradiate meat and vegetables. (Sounds like the opening scene of a B movie.)
• It’s not dangerous (in the way you think it is).
  It’s true that the process causes chemical changes, but so does the food processing technology known as cooking. Still, as the high-energy gamma rays, x-rays, a...