1 post tagged “thermodynamics”
Bill Bryson, in A Short History of Everything, includes a section on most major fields of scientific inquiry, and makes them accessible to us amateurs. In a section on the laws of thermodynamics, here's how Bryson clarifies each law for us (except the zeroth, which states, "If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other."
First law:
"for a thermodynamic cycle the sum of net heat supplied to the system and the net work done by the system is equal to zero"
Bryson translation:
"you can't create energy"
Second law:
"The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium"
Bryson translation:
"a little energy is always wasted"
Third law:
"As temperature approaches absolute zero, the entropy of a system approaches a constant"
Bryson translation:
"you can't reduce temperatures to absolute zero - there will always be some residual warmth"
To be certain we understand how these laws came about, Bryson quotes the following from P. W. Atkins:
"There are four Laws. The third of them, the Second Law, was recognized first; the first, the Zeroth Law, was formulated last; the First Law was second; the Third Law might not even be a law in the same sense as the others."
If only they'd have made it this clear when I was in school.
First law:
"for a thermodynamic cycle the sum of net heat supplied to the system and the net work done by the system is equal to zero"
Bryson translation:
"you can't create energy"
Second law:
"The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium"
Bryson translation:
"a little energy is always wasted"
Third law:
"As temperature approaches absolute zero, the entropy of a system approaches a constant"
Bryson translation:
"you can't reduce temperatures to absolute zero - there will always be some residual warmth"
To be certain we understand how these laws came about, Bryson quotes the following from P. W. Atkins:
"There are four Laws. The third of them, the Second Law, was recognized first; the first, the Zeroth Law, was formulated last; the First Law was second; the Third Law might not even be a law in the same sense as the others."
If only they'd have made it this clear when I was in school.
