I learned this today. Nobody knows why gravity exists. They can explain what happens, but not really why. Gravity can be observed, but not completely explained. Gravity is the force whereby objects with mass are attracted to each other. This force is related to the mass of the objects and the distance between them. The […]
#173 Why does gravity exist? Read More »
I learned this today. Concrete goes hard because the filler (usually something like gravel) is glued together by the binder (usually cement) through the process of hydration. Concrete is probably the most common building material in the world. Without it, our cities would not look anything like they do. Concrete has been with us for
#172 Why does concrete go hard? Read More »
I learned this today. Our bodies make energy from food by breaking it down and converting the chemical energy that is stored in it. Our bodies need energy to move and to exercise, but we also need energy just to live. Even when we think we are perfectly still, our bodies are burning energy so
#165 How do humans make energy from food? Read More »
I learned this today. No one seems to know the definite cause of Alzheimer’s Disease but it seems to be connected with the buildup of amyloid plaque in the brain, entanglement in the neurons, and inflammation of neurons. Alzheimer’s Disease was named after Dr. Alois Alzheimer. The disease had obviously existed for thousands of years,
#162 What causes Alzheimer’s Disease? Read More »
I learned this today. A battery works because the chemical reaction within it produces electrons. There are different kinds of batteries that use different chemicals, but the general principle is the same. A battery is an energy storing unit. The energy is stored in the form of chemical energy. A chemical reaction happens that causes
#159 How does a battery work Read More »
I learned this today. Dinosaurs were able to grow so big because they had hollow bones, could get more nutrition out of less food, and they didn’t need to chew their food. The largest land animal today is the African elephant and they grow up to about 3m and weigh about 6 tons. The largest
#158 How could dinosaurs grow so big? Read More »
I learned this today. Superglue works because a chemical reaction occurs that makes it harden. Superglue is made from ethyl cyanoacrylate, which is an acrylic resin. Cyanoacrylate hardens when it comes into contact with water. Cyanoacrylate is an acrylic monomer. A monomer is a molecule that can react together with other monomer molecules to form
#156 How does superglue work? Read More »
I learned this today. What is liquefied natural gas? Liquified natural gas is gas that has been cooled down until it becomes a liquid. There are four states of matter: solid, liquid, gas, and plasma. Matter changes from one state to the other depending on how much energy the particles within it have. As more
#154 What is liquefied natural gas? Read More »
I learned this today. What is the difference between Celsius, Centigrade, Fahrenheit, and Kelvin? Fahrenheit was invented first. Celsius came next. Celsius and centigrade are the same thing. Kelvin came last. The Fahrenheit scale was invented in 1724 by the physicist Daniel Gabriel Fahrenheit. He was German by birth, but spent nearly all of his
#152 What is the difference between Celsius, Centigrade, Fahrenheit, and Kelvin? Read More »
I learned this today. A tokamak is a device that uses a strong magnetic field to keep a gas plasma in a donut shape in order to achieve nuclear fusion. Tokamaks were invented in Russia in the 1960s and the word comes from Russian. It means “toroidal chamber with magnetic coils”, which is тороидальная камера с магнитными катушками
#148 What is a tokamak? Read More »
