Facts for kids: What causes thunder and lightning?

Thunder and lightning

Lightning hitting a tree.

Thunder and lightning is a fascinating phenomenon fuelled by the interaction of subatomic particles. But let’s keep it simple. Thunderstorms begin their lives in cumulonimbus clouds. These clouds are formed from water vapour carried on rising air currents, often reaching an altitude of about six kilometres (20,000 ft). At this height the air is colder than it is at sea level. Drops of water, hailstones and specks of ice form and collide with each other. This is where the magic begins.

An electrical charge is created within the cloud. The top of the cloud takes on a positive charge as protons rise, while electrons descend to the bottom of the cloud. The negative electrical charge at the bottom of a cloud creates a positive charge in the ground underneath it. As the negative charge gets stronger, the air cannot stop it from jumping from the cloud towards the positive charge on the ground.

The result is a giant spark of electricity, also known as lightning.

Thunder is the product of lightning. The temperature of a lightning bolt reaches up to 30,000 C (54,000 F), or about six times hotter than the surface of the sun. The bolt heats the air around it causing it to expand and then contract. The result is a shockwave that you hear as thunder.

Short answer: Lightning is a flash of light created by electric discharge. Thunder is a soundwave created by the rapid expanison and contraction of air.

Facts for kids: What is the oldest known rock?

The oldest known rock

The oldest known rock was formed during the Hadeon.

The oldest known rock on Earth is located in Western Australia. Scientists recently discovered an ancient crystal called a zircon and dated it to around 4.374 billion years old. Because erosion carves the land, continents drift, volcanoes erupt and seas rise and fall, finding any evidence of early Earth is quite difficult.

The crystal hails from a time known as the Hadean Eon. The Earth was highly volcanic, had a partially molten surface and was frequently struck by meteors, asteroids and comets. The planet was lifeless and extremely violent.

The zircon itself isn’t much to look at. It’s about the size of a house dust mite and located inside an existing rock. It’s not exactly the kind of thing you’d find on a casual walk in the bush.

Short answer: The oldest known rock comes from Australia and is nearly 4.4 billion years old. In comparison the Earth is around 4.54 billion years old, and the moon nearly 4.5 billion years old.

Facts for kids: Who invented concentration camps?

concentration camps

Over 30,000 people allegedly died in camps during the Second Boer War.

Despite what you might have read or heard, the Nazis didn’t invent the concentration camp. They did something much worse. During World War Two, Nazi Germany operated extermination camps. The camps had one objective; to kill as many enemies of the German nation as possible. Enemies included political opponents, Jews, gypsies, homosexuals, and communists.

Concentration camps, on the other hand, have a longer history. With the goal of controlling populations of people by locking them up in a confined area, evidence suggests people were doing this to each other in ancient Babylon more than 3500 years ago.

In modern times, concentration camps have been used by many governments to maintain their power. In 1838 the indigenous Cherokee population were locked up by the administration of United States President Van Buren. The Spanish established camps in Cuba as part of their “Reconcentrado” policy during the Spanish-Cuban War of the late nineteenth century. The British locked up families of South African men during the Second Boer War in South Africa to stop the families supporting the Boers. In the 1920s the Soviets set up work camps in Siberia to quash any opposition to the communist government. The United States government locked up Japanese Americans during World War Two despite there being no confirmed threat of attack.

Short answer: It’s hard to say who specifically invented the concentration camp but the term itself became popularised as a result of Britain’s policies during the 1899-1902 Second Boer War.