I learned this today. Pluto has been classified as a dwarf planet instead of a planet because it only meets two out the of the three criteria required of a planet. The International Astronomical Union came up with the definition of a planet in August 2006. They said that an object is a planet if: […]
#18 Why isn’t Pluto a planet? Read More »
I learned this today. Hibernation is not the same as sleeping. Animals sometimes have to come out of hibernation to be able to sleep. Hibernation is basically an energy-saving technique. During the winter, the temperature obviously drops, which means that endothermic animals (animals that generate their own heat internally) need more energy to keep themselves
#17 What happens when animals hibernate? Is it the same as sleeping? Read More »
I learned this today. The mathematical symbols + plus, – minus, x multiply, ÷ divide, and = equal are not as old as we think. Mathematics itself goes back a very long way. The idea of counting began with hunter-gatherer tribes. Presumably, they would have known how to talk about adding and subtracting parts of
#16 Where do the plus, minus, multiplication, and division symbols come from? Read More »
I learned this today. Canning preserves food by killing all of the bacteria present through heat and then keeping the food in a bacteria-free, airtight can. For food to rot, bacteria need water, oxygen, a neutral pH level, and a warm temperature. The different ways of preserving food each deal with one of these. Freezing
#15 How is food canned? Read More »
I learned this today. Leather is strong because the collagen fibers in the animal skin are strengthened and bolstered by other chemicals. It can take up to ten weeks to make leather. Making leather is a complicated process. The first thing is to remove the hide. The skin of any animal can be used to
#14 How is leather made? Why is it so strong? Read More »
I learned this today. A gun silencer works by reducing the speed of the gases that push the bullet out of the barrel, but it cannot silence the sound of the sonic boom from the bullet. A gun fires a bullet that comes from a cartridge. The cartridge that you load into a gun has
#13 How does a gun silencer work? Read More »
I learned this today. Alcohol gets people drunk because it is a depressant and slows down the speed at which the brain can send signals. Most alcoholic drinks contain ethanol which is produced when sugars are fermented. It naturally occurs in nature. Humans have drunk alcoholic drinks for thousands of years. They probably started by
#12 How does alcohol make us drunk? Read More »
I learned this today. Before the invention of the elevator (lift for my British friends), wealthy people lived on the lower floors of a building because they didn’t want to climb stairs. People had no choice and climbed the stairs to the cheaper apartments. Before the invention of the elevator, the highest a building could
#11 How did the elevator change our lives? Read More »
I learned this today. Seasickness is caused because of a discrepancy between the vestibular system and the eyes. Just inside your head, you have your inner ear which is used for sound detection and for balance. The balance part is what causes seasickness. There are two parts: the cochlea and the vestibular system. The cochlea
#10 What causes seasickness? Read More »
I learned this today. An airbag can inflate so quickly because it contains sodium azide, which produces nitrogen gas when it ignites. When you are in a car crash, a series of steps happen to launch the airbags. An accelerometer measures that the car has rapidly decelerated. Impact sensors work out where the impact has
#9 How can an airbag inflate so quickly? Read More »
