DO You Know? | 2019-02-28 |


DO You Know?

27th February, 2019 08:51:44 printer

• Earth is the only known planet where fire can burn. Conversely, the more oxygen, the hotter the fire. Air is 21 percent oxygen; combine pure oxygen with acetylene, a chemical relative of methane, and you will get an oxyacetylene welding torch that burns at over 5,500 degrees Fahrenheit.

• Oxygen supply influences the colour of the flame. A low-oxygen fire contains lots of uncombusted fuel particles and will give off a yellow glow. A high-oxygen fire burns blue.

• Candle flames are blue at the bottom because that’s where they take up fresh air, and yellow at the top because the rising fumes from below partly suffocate the upper part of the flame.

• Charred bones and wood ash indicate that early hominids were tending the first intentional fires more than 400,000 years ago.

• The ancient Greeks started fire with concentrated sunlight. A parabolic mirror that focuses solar rays is still used to ignite the Olympic torch.

• In every 52 years, when their calendar completed a cycle, the Aztecs would extinguish every flame in the empire. The high priest would start a new fire on the ripped-open chest of a sacrificial victim. Fires fed from this flame would be distributed throughout the land.

• The Black Dragon Fire of 1987, the largest wildfire in modern times, burned some 20 million acres across China and the Soviet Union, an area about the size of South Carolina.