Nanodiamond thermometer can find the temperature inside a single living cell

The mercury-in-glass thermometer has served us well for the past 270 years, but sometimes you need something smaller -- say to find the temperature inside a single living cell. Researchers at Harvard have discovered a new technique using lasers and diamond nanocrystals to measure temperatures of microscopic structures, recording temperature fluctuations as small as 0.05 Kelvin (0.09ºF) in size.