Why do we get jet lag? We get jet lag because rapid travel puts our circadian rhythm out of sync with the local time. Jet lag is a fairly recent problem. In fact, the expression “jet lag” was only coined in 1966. The reason for this is that you have to be able to jump […]
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Why are there many different types of screw head? The different types of screw head allow for different amounts of torque and for use by different machines. There are over 30 different types of screw head. Prehistoric people generally joined things together using adhesives. The earliest known adhesive was a tar made from heating birch
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How does LiDAR help archaeologists? It can map the ground down to the millimeter, allowing archaeologists to find the remains of cities and graves that might otherwise remain hidden. LiDAR stands for Light Detection and Ranging. It is similar to sonar and radar, but it uses light instead of sound waves and radio waves. Sonar,
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Why do mustard and wasabi make your nose hurt? Mustard and wasabi hurt your nose instead of your tongue and throat because the oil in them turns into a gas. Spices such as mustard and wasabi affect us in a very different way to chili. When you eat a spicy chili, the capsaicin in the
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Why are sunsets such beautiful colors? The beautiful colors of sunrises and sunsets are caused because light rays are scattered by particles in the sky. Light has different wavelengths and our eyes have evolved to detect these wavelengths, which is how we can see colors. Our eyes have a light-sensitive area which is sensitive to
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How do metal detectors work? Metal detectors work by transmitting an electromagnetic field that energizes any metal near it. There are three different types of metal detector and they all work in slightly different ways. These different types are very low frequency (VLF) detectors, pulse induction (PI) detectors, and beat-frequency oscillator (BFO) detectors. VLF detectors
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What is the smallest thing an electron microscope can see? An electron microscope can see atoms that are 0.05 nanometers long. 0.05 nanometers is a very difficult number to imagine. How small is it? Well, a human hair is about 50,000 nanometers across. There are different types of microscopes. The basic type that students use
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How does body armor work? By breaking up the bullet and removing its kinetic energy. Armor has been around for a long time, but it has always had to adapt to the technology of weapons. In the Bronze Age, they had bronze armor because it was enough to stop a bronze sword blade. Then the
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Why do mosquito bites itch? Mosquito and insect bites itch because the immune response is triggered after the mosquito finishes biting. There are over 110 trillion mosquitoes from 3,000 different species around the world. I have no idea how they managed to calculate the number of actual mosquitoes. The word “mosquito” comes from Spanish where
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What is chewing gum made of and what happens if you swallow it? These days, chewing gum is just a gum base with sweeteners and a plasticizer. You can swallow it without any harmful effects. Humans have used something to chew on for thousands of years. A 5,000-year-old lunch of birch bark tar with toothmarks
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