Most grains of sand originally started as part of a larger rock.
Many ocean-going life forms draw calcium from the water around them, and use it to secrete a hard exoskeleton, seashells for example.
Fogbows are created in much the same way as normal rainbows are. The main difference is the size of the water droplets which affect the light's refraction.
An electrical current will always follow the path of least resistance between any two points.
The narrow range of angles at which the colors are reflected is the key to why rainbows must be curved.
Have you ever wondered why some baseball players slide feet first and some slide head-first? Does either way provide an advantage?
Beyond our atmosphere flies a lot of debris. Some fragments can be larger than mountains, but most is space-dust.
Cats have six sense organs. The sixth is known as the "vomeral-nasal organ," and can be thought of as a second nose.
Amber tinted sunglasses make things appear much sharper because they block the blue and red parts of sunlight.
Fossil teeth are the most durable remnants that anthropologists work with, and some of these ancient teeth display a curious set of grooves.
If your eyesight is good, you probably think everything you see is always in sharp focus, like a photograph; this isn't the case.
During a "meteor shower" bits of rocky material that enter our atmosphere from space burn up because of friction.
Over one hundred and seventy different species of bird have been observed sun-bathing.
Scientists developed a technique to identify the residue of fats from cows' milk on ancient pieces of pottery.
Every time you eat sugar, in-mouth bacteria feed on the carbs and produce acid that harms the teeth.
Stroke is the number one cause of adult disability, and treatment is only effective if the patient gets to the hospital within three hours.
In recent years, palaeontologists have unearthed some of the smallest dinosaurs known - not bigger than 20 feet.
Chemotherapy works well for some people or cancers, but not as well for others.