How does an iron lung work? An iron lung works by creating a space of negative pressure to inflate the lungs. You have probably seen images of people in an iron lung. It was typically a cylindrical contraption, slightly longer then the height of the patient. It had a hole for the head to stick […]
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What was operation Paul Bunyan? Operation Paul Bunyan was an operation by American forces in 1976 to cut down a poplar tree in the Korean Demilitarized Zone in retaliation for the killing of two United Nations Command officers by North Korean soldiers. The operation was named after Paul Bunyan who was an American legend. He
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What was the Green Book? The Green Book was a list of places that would serve African Americans when they travelled around the USA between the 1930s and the 1960s. It was written by Victor Hugo Green, so he named it the Green Book after himself. The full name of the book was “The Negro
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What was the ghost army in World War Two? The ghost army in World War Two was an American army unit that was responsible for tactical deception and misleading the enemy. Nowadays, this kind of warfare is common sense, but it was the first such unit of its kind? The ghost army was officially called
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Which of the planets have an atmosphere? All of the planets in our solar system except for Merucry actually have an atmosphere, but they vary in thickness. We all obviously know that our planet has an atmosphere and what it is made of. It is 78% nitrogen, 21% oxygen, 0.9% argon, and the rest is
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How do circadian rhythms work? Your circadian rhythm is governed by a small group of cells in the center of the brain called the suprachiasmatic nucleus. Most living organisms has a circadian rhythm. It governs the processes of the organism and sets a cycle over a 24-hour period. The word “circadian” is from the Latin
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What are quantum dots? Quantum dots are nanocrystals that can be used as semiconductors. You might find them in your TV screen, among many other things. Different size quantum dots produce different colors. Quantum dots are called quantum dots because they are so small. They are basically nanoparticles. The smallest ones are 2 nanometers across
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When did the first trees appear? The first trees appeared about 350 million years ago and they evolved from seedless plants. There had to be plants before there could be trees and the first plants evolved about 400 million years ago. The first plants evolved from a type of freshwater green algae, but there were
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Why do birds eat rocks? Birds eat rocks to grind up their food so that they can digest it more easily. Most birds swallow rocks, and the size of rocks they eat depends on the size of the birds. A small bird like a swallow will have tiny pieces of grit, and a large bird
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What is a theodolite? A theodolite is a precision instrument used in surveying. Without it, people wouldn’t have known how tall our mountains were. Theodolites are still used for surveying today, but they have changed a lot to the earlier ones used. These days, theodolites are digital. The theodolite became common in surveying in the
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