How do reflexes work? They work by using a reflex arc that bypasses the brain. There are many different types of reflex, but they are generally meant to protect us and to allow us to move around without having to think about everything. Our brains have a limited amount of processing space and if we […]
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What is the Doppler effect? The Doppler effect is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. All energy travels in waves. Some waves, such as sound waves, have to have a medium to travel through and some waves, such as light waves,
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How do amphibians breathe underwater? They breathe through their skin. The word “amphibian” comes from the Greek amphi, meaning both and bios, meaning life. The word was first used in the 1630s and it was used to mean animals that “have two modes of existence”. There are about 7,000 different types of amphibians in the
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When were credit cards invented? The first use of the phrase “credit card” was in 1887. A credit card is a system whereby a customer can pay for goods using a line of credit from the credit card provider. The credit card provider basically pays for the goods upfront, and the customer reimburses the credit
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What are the crown jewels? The crown jewels are a collection of 142 objects, many are used in ceremonies such as the coronation. The Crown Jewels are made up of 13 crowns, 6 swords, 6 sceptres, 16 trumpets, 13 maces, 3 robes, 3 rings, 3 coronets, 2 orbs, 1 spoon and bottle, and lots of
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How did the Polynesians navigate? They used star compasses, maps of waves made using sticks, clouds, the color of the sky, and birds. From about 5,000 years ago, groups of people started to spread out from Taiwan into South East Asia. These were the people we call Polynesians. By 1200 AD, they had spread across
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What was the Carrington Event? It was the largest ever geomagnetic storm in recorded history? The Carrington Event lasted from the 1st to the 2nd of September 1859. It was observed by an amateur astronomer called Richard Christopher Carrington; hence its name, and it was caused by a very bright solar flare. From August of
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What causes brain damage? There are several things that cause brain damage. These can be traumatic injury, poison, stroke, tumor, or lack of oxygen. The brain weighs about 1.5 kg on average and contains over 100 billion nerve cells. It uses 20% of the body’s energy, which is more than any other organ. Obviously, without
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How did the Black Death change society? It ended serfdom and slavery, improved worker conditions, brought a recession, harmed religion, increased antisemitism, improved medical practice, improved women’s rights, and changed the world of art and fashion. There were three major plagues, but let’s look at the middle one, the one that is most famous. It
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How did the Black Death spread? It was spread by people along trade routes. The Black Death is another name for bubonic plague, which is caused by a bacteria called Yersinia pestis. Y. pestis generally lives in fleas that feed on rats. When the flea bites the rat, the bacteria passes into the rat’s blood.
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