Where did the circus come from? The modern circus was invented in 1768, but the idea of a show in an amphitheater goes back thousands of years. The word “circus” comes from Greek, through Latin into English. It simply means “ring” or “circle” and the Romans used them to show horse and chariot races, battle […]
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How are tower cranes assembled? By raising themselves up and adding in a piece at a time. There are many different types of cranes, but they are divided into two categories: mobile and fixed. We are looking at the cranes that are used to build skyscrapers today, and they are fixed tower cranes. Any type
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Why does an elastic band stretch? Because it is made of long chains of polymers that would rather be tangled together than straight. Rubber is famous for its ability to expand and return to its original size without any damage. There are natural rubbers and synthetic rubbers. The English word “rubber” was first used in
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How does antibiotic resistance happen? Bacteria develop the ability to survive an antibiotic, which is then passed on to future generations. The antibacterial power of some moulds has been known about since 1874, possibly even earlier. In 1897, Ernest Duchesne published a paper about the ability of moulds to kill bacteria. Alexander Fleming noticed that
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How does a skeleton key work? By removing all of the parts that would get caught on the wards. Skeleton keys are also known as pass keys or master keys. They are called “skeleton keys” because all of the main parts of the key have been stripped off and only the skeleton is left. People
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When did supermarkets start? The first supermarket was opened in 1916. Most of us don’t think twice about pushing a cart around a supermarket and then heading to the cash register to pay. However, that is a concept that is only slightly over 100 years old. A few changes in society had to happen before
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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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