Let's engage the first law of thermodynamics.
Classical Thermodynamics. So, thermodynamics has at its foundation
three fundamental laws. And with considerable lack of
imagination, they are named the first law, the second law and the Third Law.
There are no known exceptions to these laws.
You might recall in the first week I discussed an attempt by an American
inventor to manufacture an exception to the First Law, it was unsuccessful.
We're going to study the First Law, which is remarkably simple and yet remarkable
powerful. And you can answer important questions,
such as does a gas cool upon expansion? What are energy changes associated with
chemical reactions? Exclusively from knowledge of the first
law of thermodynamics. The first law can be expressed in a
variety of ways. A colloquial one that's reasonably simple
to remember and reasonably accurate is to say that energy can be neither created
nor destroyed, but it may be distributed in different ways.
And put even more succinctly, we could say: energy is conserved.
So, let me spend a little time talking about the history of the first law before
we dive into any equations. And shown on this slide is Antoine
Lavoisier. So, a father of modern chemistry.
It turns out if you trace research advisors back, I trace back to Lavoisier.
So, I just love looking at my great great great dissertation grandfather, perhaps.
And he's shown here with Madame Lavoisier, who helped him in his
scientific studies. So, they were a team, and it looks like
they have some interesting piece of apparatus there, along with a feather
quill. One did science in different ways back in
those times. So, this was not one of Lavoisier's
glorious moments. in fact, when it comes to thermodynamics,
and in particular, what I want to talk about is heat.
So going back to the ancients, there has been considerable philosophic and
philosophical, and scientific discussion of what is heat?
And so, Lavoisier who did wonderful things for chemistry.
He eliminated the phlogiston theory of chemistry, which said that when you
burned things, stuff left those things, as opposed to actually oxygen adds to
those things we know now. But at that time, people thought
phlogiston was being liberated when you burn something.
So, score one for the Lavoisier there. But when it came to heat, actually he had
an incorrect view of things. He said that heat was an invisible fluid
and it was called caloric, and it flowed from warm bodies to cooler ones, that's
how heat was transferred. There was this flow of heat, and you know
given the opportunities to do experimental science at the time, that
was an assumption that people bought into.
Lavoisier, as long as we're doing history, he had sort of an unfortunate
end, he was guillotined in the terror of the French revolution.
It turns out, it was hard to make your living as a scientist in those days.
instead he was also a tax collector for the royal family.
And as, as a farmer generally it was known as these tax collectors, that did
not endear him to the French people when the revolution came along.
So, it was said that Europe's best head was severed from its shoulders when he
was guillotined. But he did make wonderful contributions
to chemistry, and we remember them even if caloric wasn't one of them.