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 […]
#307 How does an AED work? Read More »
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
#306 Why are we running out of helium? Read More »
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
#304 Why can we only hear certain frequencies? Read More »
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
#296 Could nuclear fusion power the Earth? Read More »
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
#293 How does a rocket engine work? Read More »
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
#283 Why are some places more humid than others? Read More »
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
#280 How does fly spray work? Read More »
I learned this today. How does a desalination plant work? A desalination plant makes freshwater from seawater by using reverse osmosis. Humans and animals obviously cannot drink salt water. Fish have adapted to be able to do it, but we have not. There is about 35g of salt in every liter of sea water. If
#278 How does a desalination plant work? Read More »
I learned this today. High energy radiation or long exposure to radiation can damage the DNA in cells and cause radiation sickness. What is radiation? Radiation is energy that radiates from a source and travels through space at the speed of light. It travels as a wave or as particles and has an electric field
#275 How does radiation sickness happen? Read More »
I learned this today. A superfluid is a point where matter behaves like a fluid but has zero viscosity.A superfluid has no viscosity. That means it doesn’t have any friction and doesn’t lose energy. It appears to go against the laws of thermodynamics. If you stir a cup of coffee with a spoon and step
#265 What is a superfluid? Read More »
