I learned this today. Glass and metal can be recycled indefinitely, but plastic can only be recycled once or twice and paper about 7 times. Recycling has been around for as long as people have used resources. There is archaeological evidence of scrap bronze being collected and melted down again in Europe. In 1031, a […]
#193 How many times can you recycle something? Read More »
I learned this today. Our voices change when we inhale helium because sound travels through it faster than it does through air. There are two things we need to look at: Why sound travels at different speeds through different mediums and how our voices work. Sound is a wave of vibrations that travel through a
#189 Why does our voice change when we inhale helium? Read More »
I learned this today. It is possible to make a new element, but it is not easy, takes a lot of power, and the resultant element would not be very stable. There are 118 known elements that appear on the periodic table. The first 94 of them occur naturally on Earth and the other 24
#187 Is it possible to make a new element? Read More »
I learned this today. Some metals are not magnetic because the magnetic poles of the atoms within them point in different directions and are weakly repelled by both poles of the magnet. There are different kinds of magnets. Some are permanent magnets, some are magnetized metals, and some are electromagnets. Magnetized metals are magnetic only
#181 Why are some metals not magnetic? Read More »
I learned this today. There is a carefully choreographed sequence of steps that enable us to vomit. Vomiting is a form of protection. It is the body’s way of getting rid of threats or things it feels might be dangerous. This could be a poison, it could be a chemical, it could be a virus
#179 How do we vomit? Read More »
I learned this today. Nobody knows why gravity exists. They can explain what happens, but not really why. Gravity can be observed, but not completely explained. Gravity is the force whereby objects with mass are attracted to each other. This force is related to the mass of the objects and the distance between them. The
#173 Why does gravity exist? Read More »
I learned this today. Concrete goes hard because the filler (usually something like gravel) is glued together by the binder (usually cement) through the process of hydration. Concrete is probably the most common building material in the world. Without it, our cities would not look anything like they do. Concrete has been with us for
#172 Why does concrete go hard? Read More »
I learned this today. Our bodies make energy from food by breaking it down and converting the chemical energy that is stored in it. Our bodies need energy to move and to exercise, but we also need energy just to live. Even when we think we are perfectly still, our bodies are burning energy so
#165 How do humans make energy from food? Read More »
I learned this today. No one seems to know the definite cause of Alzheimer’s Disease but it seems to be connected with the buildup of amyloid plaque in the brain, entanglement in the neurons, and inflammation of neurons. Alzheimer’s Disease was named after Dr. Alois Alzheimer. The disease had obviously existed for thousands of years,
#162 What causes Alzheimer’s Disease? Read More »
I learned this today. A battery works because the chemical reaction within it produces electrons. There are different kinds of batteries that use different chemicals, but the general principle is the same. A battery is an energy storing unit. The energy is stored in the form of chemical energy. A chemical reaction happens that causes
#159 How does a battery work Read More »
