Fun Science: Things We Cannot See
Professor Gizmo (Amazing Science Presentations) gives expert video advice on: What is an "atom"?; What are "germs"? and more...
What is a "molecule"?
A molecule is basically the smallest part of a substance. The molecule itself is very small and it's made up of atoms, but it is the smallest part of a substance. Like salt, you can get a molecule of salt, you take that molecule and break it down even more; it's no longer salt.
What is an "atom"?
Atoms are actually the building blocks of everything. Every single thing on this earth is made up of atoms and molecules; and they together form human beings, they form rocks, they form wood, they form plants, they form animals. So it's the building block of life. Yep, same thing that makes you makes a rock, but it's in different proportions and different amounts. We have a lot more water in our makeup than a rock does. We have more carbon in us than a lot of rocks do. So it's the chemical makeup, the different amounts of substances and how they work together and how they mesh together that make different objects in this universe.
What are "noble gases"?
Noble gases are gases that are not really noble, but they're given that term because they don't react with things. When I say 'react with things', I mean we can mix these noble gases with anything and it just doesn't seem to do anything. It's just very unreactive. So these gases are used in certain places, like neon is a noble gas, argon is a noble gas, so is helium. Helium would have been a much better thing to use in the durigibles or the balloons that have been flying around, because there was one; the Hindenburg, which used hydrogen. Now, hydrogen was a reactive gas and when it started to burn it burned very, very strongly. So, it's these noble gases, that if there was helium in that durigable, it would not have burned because it is a unreactive gas.
What are "germs"?
Germs are a term that refer to, it could be bacteria, it could be viruses. Small organisms that we refer to as basically causing us problems, diseases, sickness, illness and we just kind of use that common term "germ" to cover all of that. Germs are really small. You can't see them without the use of a microscope. In fact, viruses you'd have to use sometimes an electron microscope which would magnify things in the thousands of times. So, they are so small we can't see them and yet they are the type of thing that they're good for some of the things that we do. Some of the germs, if you want to use that term, are beneficial to us and some of the germs are harmful to us. If the germs are virus, there is not much we can do except have our bodies take care of viruses. If the germ is bacteria, we can sometimes use medicines and treatments to kill the bacteria.
What is a "mirage"?
A mirage is something that you're seeing that's not even there. A mirage is created sometimes by a difference in air temperatures. I noticed a mirage the other day when I was driving. It was very hot out, and if you look very far out in front of the car, it looks like the road is wet. It's not wet at all. It's because of the heat coming off the road bending the light waves. When it reaches our eyes, it looks like it's wet. So a mirage is something that our eyes are seeing that's not really there.