How tall could a skyscraper be? Theoretically 69.1 km tall, but practically, about 2 km. The tallest building in the world at the moment is the Burj Khalifa. It is 830 meters tall. For over 3800 years, the tallest building in the world was the Great Pyramid at Giza. It was 147 meters tall when […]
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How does an electroencephalogram work? By measuring electrical activity in different parts of the brain using electrodes on the scalp. EEGs are used to diagnose disorders with the electrical activity in the brain. These can be epilepsy, sleep disorders, anesthesia, coma, and even brain death. It is most commonly used for diagnosing epilepsy, which is
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Is nuclear waste dangerous? It is if it isn’t handled properly. This was interesting to research. All of the sites I looked at that were run by nuclear organizations said, “no, no, of course not,” while the sites I looked at from other sources said, “possibly.” When we think about nuclear waste, we think about
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How does an AED work? It has sensors to detect the rhythm of the heart and it has a powerful battery to deliver a shock to correct the heart. AED stands for Automatic External Defibrillator. It is a defibrillator that is automatic. So, let’s start by finding out what a defibrillator is. A defibrillator is
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Why are we running out of helium? It is a non-renewable resource that we are rapidly using up. Many people don’t give a second thought about helium. It is the second lightest element and the second most abundant element in the universe after hydrogen. It is thought to make up 24% of the total elemental
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Why can we only hear certain frequencies? Our cochlea is only stimulated by frequencies between 20 Hertz and 20,000 Hertz. First, let’s look at how we actually hear. Our ear is a detector for sound waves. It is shaped to funnel them into the ear canal, which ends in the eardrum. The sound waves make
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Could nuclear fusion power the Earth? Yes, but not in this half of the 21st century. Nuclear fusion and nuclear fission are the two ways we can get energy out of an atom. Nuclear fission is the easiest of the two for us to perform on Earth. In nuclear fission, a neutron is fired at
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How does a rocket engine work? Rocket engines work because of Newton’s third law of motion. Newton’s third law of motion states “to every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal, and directed to contrary parts.” Or, in other words, for
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I learned this today. Why are some places more humid than others? It is because they are closer to a large, warm body of water, which causes warm winds and warm air can carry more water vapor than cold air. What is humidity? Humidity is the concentration of water vapor in the air. The air
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I learned this today. How does fly spray work? By blocking the insect from using its nerves to move its muscles. There are two kinds of fly spray. There are repellents, which are sprays you apply to your body to stop insects landing on you and biting. Then there are insecticide fly sprays that kill
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