Brightening Up Traffic

Haleh Cohn — Thu, 12 May 2022 15:41:45 +0000

Red signifies danger in many cultures. From a distance, green is highly visible by day. At night, yellow is easier to see. That briefly explains the choice of colours on every traffic light. But what makes lights emit those colours in the first place?

You Can Still See the Division of East and West Berlin from Space

Ada McVean B.Sc. — Wed, 30 May 2018 19:40:00 +0000

Berlin might be united now, but evidence of its 40-year history of division still remains.

This photo, taken by Commander Chris Hadfield, shows a divided Berlin, with the East appearing orange and the West white. But why?

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Brightening Up Traffic

You Can Still See the Division of East and West Berlin from Space