Perhaps one of the finest examples of evolution in action were the finches of the Galapagos Islands. Each island had a different species of finch, and each species of finch had a different sized beak. The finches with the largest beak lived on an island with plenty of hard nuts, while the smallest-beaked finch lived on an island where the main food source was insects. This showed how well these birds had adapted to their environment.

Nimbus means "rain" when added to a cloud's name. Nimbostratus are dark, low-level clouds accompanied by light to moderately falling precipitation, and Cumulonimbus are dense towering vertical clouds associated with thunderstorms.

Although it was a long-held belief that the Stegosaurus had three brains: One in its head, one in its back, and one in its tail, recent studies have shown that these extra "brains" were actually energy stores for muscles. So the Stegosaurus had only one brain, and not a very big one at that!

An anemometer is used to measure wind speed. The first mechanical anemometer was invented in 1450 by Italian artist and architect Leon Battista Alberti.

The appearance of modern man about 100,000 years ago was marked by a decrease in body size at the same time as an increase in brain size. However, it is worth noting that Neanderthals, which became extinct about 40,000 years ago, had larger brains than modern Homo sapiens.

The three smallest bones in the human body are located in the middle ear. Individually, they are known as the malleus, incus, and stapes. Collectively, they are called the ossicles. Their purpose is to convey sound from the outer ear to the inner ear.

In 1800, Alessandro Volta discovered that certain fluids would generate a continuous flow of electrical power when used as a conductor. This discovery led to the invention of the first voltaic cell, more commonly known as a battery.

The ionosphere is an abundant layer of electrons and ionized atoms and molecules that stretches from about 48 kilometers (30 miles) above the surface of the Earth to the edge of space at about 965 km (600 mi). This dynamic region grows and shrinks based on solar conditions. Because of its high concentration of ions and free electrons, this region is able to reflect radio waves and makes radio communications possible.

While in flight, hummingbirds have the highest metabolism of all animals (excluding insects). Their heart rate can reach as much as 1,260 beats per minute.

Because Einstein's general theory of relativity was considered too controversial, he was awarded the Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."