2014-03-5 2f5e9b07ed3e09346e297ba2806de97b3ca443a3 4 infrared sensor 1 /wiki/infrared%20sensor infrared sensor Infrared sensor /feed/2014/03/5/an-1800-year-old-egyptian-papyrus-discovered-a-century-ago-whose-inscription-is-nearly-illegible-to-the-naked-eye-has Live Science 5 3e7e5f472257bb86fa9d9a70efdded99dc0a7a7b 3 http://www.livescience.com/43900-ancient-egyptian-soldier-letter-deciphered.html 2014 An 1,800-year-old Egyptian papyrus discovered a century ago, whose inscription is nearly illegible to the naked eye, has been made more readable using infrared sensors, revealing the message to be a soldier's letter to his family.