Did You Know?

Birds Need Gravity To Swallow Food

Birds can't be brought into the outer space because birds need gravity to swallow food. NASA put on an experiment with a bird, they brought bird into the space and after the ship passed the gravity level the bird was not eating anything and it had some balancing problems.

NASA officials thought that it was just a gravity problem but suddenly the beak of the bird was pointed to the ground every time. It was not lifting the beak, then the team noticed birds need gravity to lift their beak.

Traffic Lights In Use Before The Advent Of Motorcars

Traffic lights were used before the advent of the motorcar. In 1868, British railroad signal engineer J P Knight invented the first traffic light, a lantern with red and green signals.

 It was installed at the intersection of George and Bridge Streets in front of the the British House of Commons to control the flow of horse buggies and pedestrians. Motorcars were introduced to the US in the late 1890s and the need for traffic control soon became obvious. 

A number of people came up with ideas for traffic control. In 1910, Earnest Sirrine of Chicago, Illinois filed for a patent for what is considered the first automatic street traffic system, using non illuminated words STOP and PROCEED.

 In 1912, Lester Wire of Salt Lake City, Utah invented an electric traffic light that used red and green lights. However, he did not apply for a patent. 

The first traffic light system to use red and green lights were patented by William Ghiglieri of San Francisco, California in 1917. His design could be operated manually or in automatic.

Source: didyouknow.com