I learned this today. A spray bottle works by breaking the liquid up into tiny droplets using a pump and different kinds of nozzles. Modern spray bottles work slightly differently to older spray bottles. The first kind of spray bottles used a rubber bulb and an atomizer nozzle. They were invented by an American called […]
#242 How does a spray bottle work? Read More »
I learned this today. The Sahara Desert has grown so big because the precession of the Earth’s axis as it rotates around the sun changes the location of the African monsoon. The Sahara Desert is 9.2 million square kilometers, which makes it bigger than every country except for Russia, Canada, China and the USA. The
#229 How did the Sahara Desert get so big? Read More »
I learned this today. Different countries have different laws, but the first bankruptcy laws were created in 1542 in England. The word “bankruptcy” comes from the Italian banca rotta, which means “broken bench”. The story is that bankers used to do their business over a bench. If a banker defaulted on a loan
#226 When did bankruptcy laws start? Read More »
I learned this today. The Kola borehole is the deepest manmade borehole on Earth, and it is the deepest artificial point on Earth. The Kola borehole is on the Kola Peninsula, which is on the Russian border with Norway. It is in the very far north of Russia and is in the Arctic
#225 What is the Kola borehole? Read More »
I learned this today. Radar works by using radio waves to work out the position of objects relative to the detector and sonar uses sound waves. Radar works in a similar way to sonar, but it is far more effective in air. A sonar system sends out a sound and waits for the sound
#221 What is the difference between sonar and radar? Read More »
I learned this today. Hawai’i became a state in 1959, when 93% of Hawaiians voted in favor of it. People have only lived on the islands of Hawai’i since about 400 AD. Polynesians sailed there from the Marquesas Islands, which are about 3200 km away. They settled the islands and fished and farmed
#220 Why did Hawai’i become a US state? Read More »
I learned this today. The Trieste, a Swiss and Italian submarine reached a depth of 10,911m. This is the deepest point on Earth and is the Challenger Deep of the Mariana Trench. Different submarines can reach different depths, depending on what they are needed for. A submarine that is built to go deep
#218 How deep can a submarine go? Read More »
I learned this today. Glass and metal can be recycled indefinitely, but plastic can only be recycled once or twice and paper about 7 times. Recycling has been around for as long as people have used resources. There is archaeological evidence of scrap bronze being collected and melted down again in Europe. In 1031, a
#193 How many times can you recycle something? Read More »
I learned this today. Maslow’s hierarchy of needs is a universal classification system which has the most important needs at the bottom and then the following needs in an ascending order of importance. Maslow was an American psychologist. He worked from the early 1930s until his death in 1970. He published his hierarchy of needs
#191 What is Maslow’s Hierarchy of Needs? Read More »
I learned this today. Vellum is a material for writing on that is made from prepared animal skin. The document on the front of this article is the Magna Carta. It is the document that tried to control King John of England and is one of the most famous documents in the UK. It was
#186 What is vellum? Read More »
