I learned this today. The construction of the Berlin Wall began on the night of Sunday 13th August. A day that is called Barbed Wire Sunday. At the end of World War 2, the defeated Germany was divided up among the allied powers: America, Britain, France, and Russia. Each power occupied a quarter of the […]
#38 Why was the Berlin Wall first built? Read More »
I learned this today. Standardized time and time zones weren’t needed until rail travel became popular in the 1850s. Having international time zones seems common sense to us these days. How can you conduct business in New York from London if you don’t know what time it is there? And knowing how many hours ahead
#37 Why did we start using time zones? Read More »
I learned this today. The most common kidney stones are caused when there are more minerals in the blood than the kidneys can reabsorb. Most people have two kidneys. The kidneys have three jobs that they do for us. Their first job is to filter waste products out of the blood. Together, they filter 200
#36 How do kidney stones form? Read More »
I learned this today. Fireworks that are shot into the sky are made up of a stabilizer, a fuse, a charge, and an effect section. Fireworks that are launched into the sky were invented in China in about 1200 AD, but explosive fireworks were invented much earlier than that. Gunpowder was invented in about 142
#35 How do fireworks work? Read More »
I learned this today. Ships float because the density of the total volume of the ship is less than the density of the same volume of water it displaces. An object will float on a liquid if it is less dense than the liquid it is floating on. The density of water is 997 kg/m3.
#34 Why do ships float? Read More »
I learned this today. The Kardashev scale describes five different levels of technological civilization, and we, as a species, haven’t even reached level 1. The Kardashev scale was, unsurprisingly enough, thought up by a Russian astrophysicist called Nikolai Kardashev in 1964. He originally decided on three types of civilization, but this has been extended to
#33 What are the 5 types of civilization? Read More »
I learned this today. Scars are left after a wound because the body is trying to put a protective covering over the wound as fast as it can. When you cut your skin, if it is more than a surface graze, you start to bleed. The first thing that happens is your blood clots. There
#32 Why do wounds heal with scars? Read More »
I learned this today. Neanderthals were named after the place where they were found. The Neander Valley in modern Germany. “Thal” means valley in German. The earliest Neanderthal bones found were in 1829 in Belgium. A Dutch naturalist called Philippe-Charles Schmerling found a skull, but he thought it was a fossil of a human skull
#31 Why are Neanderthals called “Neanderthals”? Read More »
I learned this today. Venus flytraps know when to close on an insect because of tiny hairs inside them. Venus flytraps are carnivorous plants that grow in the subtropical wetlands of the United States. They live in nutrient-poor soil, specifically nitrogen-poor soil, which is the main reason they have evolved to eat insects. The plants
#30 How does a Venus flytrap know when to close? Read More »
I learned this today. Floor indicators were added to elevators in the 1950s in order to distract people while they waited. The actual waiting time wasn’t as bad as the perceived waiting time. This was discovered thanks to queuing theory. Queuing theory was invented by Agner Krarup Erlang in 1909. He was working for the
#29 Why will people happily wait in a queue? Read More »
