Answer: A billion years
More information: Generally, an eon actually often refers to an indefinite amount of time
More information: The CO2 levels have risen about 40% since the industrial revolution. As of March 2011, the CO2 level was about 0.04%.
Answer: 8 minutes and 20 seconds
More information: Photons emitted from the surface of the Sun travel across the vacuum of space to reach our eyes.
More information: There are 24 time zones, maybe more. Some time zones are only 30-45 minutes apart.