Science Logic 8/31/19

A bit about chemistry by Richard Bleil

One of the hardest things I’ve ever had to do was to give up my library. I spent my life collecting chemistry books, but, unfortunately, I simply couldn’t continue to drag it along with me as I moved from place to place.

One of my favorite quests was to find old textbooks. I’ve always been fascinated by the history of chemistry, and how they deduced what they did. For example, I had a textbook with a chapter that covered the octet rule and had a paragraph that said, I kid you not, that a new subatomic particle has been discovered tentatively called the “electron”.

The octet rule is a fascinating way to determine the bonding of chemicals. It tells us that the electrons live in pairs, and has a variety of “exceptions”. And yet, without knowing what electrons were, this book spelled out all of the rules of bonding before electrons had even been completely established.

Oh, they didn’t call them electrons. They discussed “open valences”; two open valences would form a bond. As it turns out, the idea of valences came from hydrogen. Hydrogen always formed the same number with itself. In other words, carbon can form compounds with one or two oxygen (carbon monoxide or carbon dioxide), so there had to be some variable for carbon or oxygen or both (it turns out to be both). But when it’s just carbon and hydrogen, it’s always four hydrogen to one carbon. Always. Without exception. So, the assumption became that hydrogen had one “open valency”.

If hydrogen has one open valency, then that leads to the assumption that carbon must have four open valencies, and oxygen has two. When just carbon and hydrogen are in a compound, it’s 1 carbon to 4 hydrogens, so if hydrogen has one open valency, then carbon must have four. Oxygen, on the other hand, has two hydrogens for one oxygen (water, H2O). Thus, oxygen must have two open valencies.

It’s interesting how much has been deduced from pure logic in science. Gallileo figured out that objects must fall at the same rate were it not for air resistance. The “common knowledge” of the time was that heavier objects fall faster than smaller. For example, if you drop a hammer and a feather at the same time, of course the bowling ball will fall faster. Try it, Go ahead. I’ll wait.

Gallileo developed a “thought experiment”. He considered two masses one heavier and the other lighter. By the belief of the time, the heavier mass would fall faster than the lighter. Then, he suggested, that they be tied together. Now, how fast will they fall? If the lighter mass falls slower than the larger, then it should act like a drag and the two together would fall at a speed between the large and small. But,, tied together, their total mass is greater than either alone, so it should fall faster than the largest.

So which is correct? Honestly, they’re both correct. But, they cannot both be correct, so the only conclusion is that the initial assumption, that the heavier mass falls faster than the lighter, must be in error. If that’s wrong, then both objects must fall at the same rate, regardless of mass. In 1971, during Apollo 15, astronaut David Scott performed the experiment on the moon. Dropping a feather and a hammer at the same time, both fell at the same rate.

By the way, look for the video. It’s fun to watch.

Around 500 BC, a group of Greek philosophers called “Atomists” asked the question of if one split a stone in half, then split a half in half again, and split a quarter in half and so forth, could you split the stone forever, or would you eventually reach a point where one more division would result in something more fundamental, something…more elemental. A lot of people took a stone and spent a lot of effort and realized that it becomes harder, but the stone is always stone. The Atomists suggested, however, that eventually you would get something more elemental, and suggested that everything in the world is made of four basic element, earth, air, fire and water. Burning logs seemed to support these elements; you see the fire being released, once burned the ash looks a lot like earth, you can see the air rising from the log as it burns, and often you’ll see steam and boiling water coming out of the end of the log, so, the log must contain all four elements.

But, the point is, the model developed by the Atomists about five hundred years before Christ was strikingly similar to the Atomic Theory proposed by John Dalton in 1803, which is still the foundation of chemistry and largely taken as accurate today.

And all based on logic.

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