The surface of hot water freezes faster than cold water but the rest of the water will remain liquid longer than in a cold sample.

Liquid air looks like water with a bluish tint.

Industrial hemp contains less than 1% of THC, the psychoactive component of marijuana.

In a desert, a mirage is caused when air near the ground is hotter than air higher up. As light from the sun passes from cooler to warmer air, it speeds up and is refracted upward, creating the image of water.

Radio waves travel so much faster than sound waves that a broadcast voice can be heard sooner 18,000 km away than in the back of the room in which it originated.

A US ton is equivalent to 900 kg (2000 pounds). A British ton is 1008 kg (2240 pounds), called a gross ton.

Hydrogen gas is the least dense substance in the world.

The double-helix structure of DNA was discovered in 1953 by James Watson and Francis Crick. The length of a single human DNA molecule, when extended, is 1.7 metres (5 ft 5 in).

A square piece of dry paper cannot be folded in half more than 7 times.

Since space is essentially empty it cannot carry sound. Therefor there is no sound in space, at least not the sort of sound that we are used to.

The crawler, the machine that takes the Space Shuttle to the launching pad moves at 3km/h (2 mph).

Luke Howard used Latin words to categorize clouds in 1803.

Earth is slowing down – in a few million years there won’t be a leap year.

A storm officially becomes a hurricane when cyclone winds reach 119 km/h (74 mph).

Earth is not round; it is slightly pear-shaped. The North Pole radius is 44mm longer than the South Pole radius.

The ozone layer averages about 3 millimeters (1/8 inch) thick.

The sun is 330,330 times larger than the earth.

The deepest point in the sea: the Mariana Trench off Guam in the Pacific Ocean; it is 10,9 km (6.77 miles) below sea level.

The tallest waterfalls in the world are Angel Falls in Venezuela. At 979 m (3,212 ft), they are 19 times taller than the Niagara Falls, or 3 times taller than the Empire State Building.

The order of the planets, starting closest to the sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

If the amount of water in your body is reduced by just 1%, you’ll feel thirsty.

The muscle that lets your eye blink is the fastest muscle in your body. It allows you to blink 5 times a second. On average, you blink 15 000 times a day. Women blink twice as much as men.

The length from your wrist to your elbow is the same as the length of your foot.

On average a hiccup lasts 5 minutes.

If all your DNA is stretched out, it would reach to the moon 6,000 times.