Matter

​Can you imagine how good this apple pie is going to be? Mmm, hey, what is the apple pie really made of? Made of? Oh, these seven ingredients: apples, butter, oats, flour, sugar, syrup, baking powder. Baking powder?

What's that made of? It's a powder that makes the pastry rise and get bigger. Okay, but what's the powder made of ? Sodium bicarbonate, some other stuff. So what's sodium bicarbonate made of then?

I don't know. Teeny tiny blocks of Lego? Philip is not the first person to ask, What is everything made of really? As long as 2500 years ago in ancient Greece, there were people who had time to think about that. Here are two of them talking about what happens if they cut something into smaller and smaller pieces.

Eventually, they must reach pieces that are so small that you can't cut them up any more. These smallest pieces were given the name indivisible, or in Greek, atomos. that we use today means The word, atom, just that, indivisible. But this idea that everything is made up of tiny atoms was not a particularly popular one. Aristotle believed that there were four types of matter, that everything was made from four elements: earth, air, fire, and water.

This idea of four elements had already been around for a long time and similar ideas existed in many other of the early civilizations. And this understanding continued to dominate for a long time. Right up to the Enlightenment. In the 18th century when scientific experimentation began in earnest. Well, in the beginning they were mostly trying to create gold.

These were the first chemists, or alchemists. They never succeeded in creating gold, but they did discover a lot of other interesting stuff. Here is one who tried to convert urine into gold. Instead he discovered the substance phosphorus. Scientists of this time soon understood that phosphorus and several other substances were not just any kind of matter.

These were the basic substances that could not be divided into their component parts. They were the elements. Scientists kept learning from each other and discovered one element after another during the 19th century. The list of elements grew longer, and longer. more than a 100 elements.

Today we know Just over 80 of them occur naturally outside of the laboratory. The most common element in the universe and the lightest is hydrogen. The most common element in the Earth's crust is oxygen. Here's an oxygen atom. If you put it together with two hydrogen atoms, you get a water molecule.

If you get together enough of these molecules, you'll eventually get a little lake. If instead you put one atom each of the elements sodium, hydrogen, and carbon together with three oxygen atoms then you have sodium bicarbonate which is what you find in baking powder. What about heat then? Is that also an ingredient in apple pie? What element is that?

Nah, heat isn't matter. It's energy. Atoms and molecules are matter. Is smell matter? Yes.

What smells are particles moving in the air. You can weigh and measure scent molecules. What about the air? Matter. Mostly oxygen and nitrogen.

Light? ‹ Not matter. Matter is stuff you can drop on your foot. Oops. But now.. Now we've got loads of apple pie matter on the floor.