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 »
I learned this today. We can’t see colors in the dark because our eyes detect light waves in two different ways. In our eyes, we have rods and cones that are both used to detect light. The cones are sensitive to light wavelengths, and we use them to see color. The rods are sensitive to
#28 Why can’t we see color at night? Read More »
I learned this today. Why would we evolve with a throat and windpipe that are so close together we can choke? In 2019, 5228 people choked to death in the United States. As a cause of death, it was the fourth highest. Chocking happens when an object, typically food, blocks the throat or windpipe cutting
I learned this today. The horse collar changed society in a huge way and many things we take for granted now came about because of the horse collar. There are different opinions, but humans probably started farming about 11,500 years ago. Many animals were domesticated at around this time as well. Fields were dug and
#26 How did the invention of the horse collar change society? Read More »
