A child with tuberculosis What is tuberculosis? Tuberculosis is a lung disease caused by germs. Today we can usually cure it with antibiotics. But in antiquity there was no cure. Many people died [...]
A kid with measles Symptoms of measles Measles is a sickness that first makes you feel sick, with a fever, a cough, and a runny nose. Then it gives you [...]
An eclipse of the moon. You can see the curved shadow of the Earth. Logic tells you the earth is round. Making predictions Once people have seen that something happens [...]
History of electricity: A bolt of lightning in the sky Why did it take so long to control electricity? Like other inventions, electricity took thousands of years to develop. For [...]
The bus is heavy, so it's hard to get it moving. Who first wrote about inertia? A law of physics first suggested by the Uzbek scientist Ibn Sina about 1000 AD states that [...]
Isaac Newton, mathematician and physicist About 1000 AD, in the Islamic Empire, Ibn Sina came up with the idea that an object moving in a vacuum would just keep moving forever without slowing [...]
Light takes years to reach us from these stars far away in space. When solid objects move through space, they follow certain rules that let us predict how they will act. We call [...]
Gravity is an important cause of acceleration Newton's Second Law of Motion tells us that force equals mass times acceleration. You can try this out for yourself. Here's a website with [...]
Kids playing tetherball using centrifugal force Who first explained centrifugal force? When something is going straight, it always keeps going straight unless something else stops it or turns it. (The [...]
Weighing the souls of the dead Philosophy means the love of wisdom. But what does that mean? It's hard to separate philosophy from religion. And it's also hard to draw a [...]
