…April 1st is April Fool’s Day

April Fool’s Day is also called All Fools’ Day. While this day has been celebrated and observed for centuries in many countries around the world, where it actually began and for what purpose is unknown and cannot be found out, unfortunately. It is similar to festivals such as Hilaria (a day of merriment and rejoicing) which was celebrated in ancient Rome on 25 March, and to Holi in India. Some say that the modern version of April Fool’s Day began in France. In August 1564, King Charles IX declared that the new year would not begin on Easter, which had been the custom until then, but rather on 1 January. But some stuck to the old date and the old ways. They were branded “April Fools.” 

Some others believe that because 1 April is close in time to the vernal equinox (21 March, when the day and night are equally long), it is observed as April Fool’s Day. During the equinox, people would be fooled by sudden changes in the weather. 

No matter how the day began, it continues to be a time for jokes and pranks. 

…we have body hair

Our ancestors used to be much hairier. In fact, our close relatives, such as chimpanzees and apes, are still quite hairy. So how did we lose all that thick hair and retain the fine ones? It’s because at some point in our evolutionary history, thick hair became more of a hassle than an advantage. 

One proposal from scientists states that our ancestors lost thick body hair to prevent parasites from spreading. Another theory links hair loss to our ancestors walking upright on two legs, two million years ago. By standing up instead of crawling on all fours, early humans exposed only a part of their body to direct sunlight. And so, a thick covering of fur wasn’t needed as Sun protection. Our ancestors’ bodies also developed a new way to regulate body temperature to make up for the loss of thick fur—sweating. With larger sweat glands, they could stay cool during the day as they hunted. Then, as they discovered fire and invented clothing, they realized they could keep cool during the day and warm at night, all without needing thick body hair. 

…red means stop and green means go

Until the mid-19th century, different railways used their own signal systems. In 1841, British railway businessman Henry Booth urged that the colour scheme for signals be standardized in Britain. He suggested that red could mean stop, while a white signal could mean go. Green would be the signal for caution. As it happens, red is also the colour with the longest wavelength; it diffuses less than other colours when it travels through the air. Therefore, it can be seen from a greater distance. 

When white began to be used as the signal for go, it caused problems for train conductors. Bright white would be mistaken for stars at night, so conductors would ignore it. Other times, they assumed that they were being given the signal that everything was clear when it wasn’t. All this confusion resulted in a catastrophic accident. The red lens of a stop sign came off which exposed the white background. This white was mistaken as a go sign and a train crashed through the stop signal. At this point, officials resolved to change things and get rid of the confusion once and for all. The green signal became the new go sign. 

Meanwhile, traffic lights were starting to appear on roads in the US. American officials decided to adopt Britain’s new colour scheme, which ended up becoming the global standard, more or less.