Commentary

The First Law, at right, implies this rule only applies to Closed Systems. It also implies it is only true of Increasing Energy. So Energy can decrease any old time. Most important, the law appears to be a Law about Systems, not about a fundamental property of Energy.

Second law is stated as a negative. Never a good beginning. And the use of the word "spontaneously", implies that heat can flow from cold to hot, as long as its not spontaneous. And it says nothing about what will happen, it says only a very specific thing will not happen in a very specific circumstance.

Third Law as stated sounds like it means something. If only we knew what Entropy means.

(Same source) Entropy is a thermodynamic property that is the measure of a system’s thermal energy per unit temperature that is unavailable for doing useful work. In a gas, Thermal Energy per unit temperature is a constant. So if Third law on the right is true, the energy from a 1 degree drop in heat goes down, as we approach absolute zero. Helium comes pretty close to a gas all the way down to absolute zero. Ideal Gas law says 1 degree is always the same energy, the "law" on the right says its not.

But the ideal gas law requires each additional unit energy creates the SAME increase in volume. If pressure is held constant, the amount of Energy it takes to grow the helium Volume 1 degree and 1 unit of volume is always the same at all temperatures. The work produced is always 1 unit Volume x 1 Unit Pressure.

So now we get to choose which to believe, the Ideal Gas law, or this version of the third law of thermodynamics.

Back to first law, same source, item "b" is similar to "a", but uses the word "change" instead of "increase". Mathematically about the same, language, not the case. "Change". Item "c" appears a direct contradiction of a and b, as "isolated" and "closed" have similar meanings. Item "c" states a true but imprecise property of Energy. The important concept, is not just that the total energy is constant, but that it is not created and destroyed, but converted from one form to another. The sum can be constant if energy is popping up from nowhere and disappearing at the same rate (which is a quantum thing). None of these statements actually mentions the central point to the First Law, energy changes form, but the total remains the same. Lets take case "a", work is both added or subtracted to the system. One cannot subtract more from the system than is there. The equation allows Energy to become negative. Item "b" has the same flaw, just less obvious. "d" comes from the first paper Physics book cracked, and is similar in form to "a" with similar flaws. Do any of these convey you get equal energy for equal energy? "d" at least defines its mystery letters. Note there is no universal convention. Q and H often represent Heat, E and U total Energy, you should really already know the First Law before you read about it, or you just won't get it.

Second Law(s) Note that a, b and c all say very different things. So What's the Law? Specifically "b" is completely incorrect. Look for windmills under chapter Theorems. Item "c" sounds like it must be true of Clausius's actual version of the law is true. However, Clausius is right, this is not. An Enclosable heat engine has this property. Clausius states the opposite, which paraphrased is "If heat flows from cold material to hot material, something else also had to happen". Any reversible engine can make heat flow from cold to hot. But they do the "something else" to make it happen. "d","e" and "f" all come from the same source. "e" and "f" both make clams about disorder, but not the same claim. "d" and "c" say approximately the same thing. "d" is true if you include the rest of the engine as "surroundings", although that's not the apparent meaning of it.

Third Law, we covered 1 above. The amount of work has to be proportional to the heat it consumes. If it consumes 1 degree worth of work, you get 1 degree worth of heat. Not only the ideal gas law requires this, but law of conservation of Energy, or Energy=Work+Heat. Notably missing is "unless a system approaches absolute zero".

Now, for really cold Crystal's. Somewhere this made sense in some context. But it does not convey any useful message about thermodynamics or heat engines, which do NOT run on crystals.

The AUTHOR of the third law, Some guy named Nernst, said the law is that you can't reach absolute zero in a finite number of steps. (next page). Not getting crystals out of that nor am I getting "infinite steps" out of crystals. Sounds like those are more like laws of Crystals, not of thermodynamics. The point is "infinite steps", easy to prove for gases (above right). Takes someone clever for solids and liquids. Which may be why Nernst got a Nobel prize. I wonder if anyone asked him, when you say "infinite steps to 0", did you really mean "something about crystals" instead? "d" is from the paper Physics book, and ironically was disproved by the crystal guys.

Perhaps the bit about crystals (A. Proves, or B. Disproves), the original third law, its not clear. Which is the point. Its not clear what this has to do with the original.

Author's note: Humor is used here to make a point, not to belittle the important work done with thermodynamics of Crystals. The laws regarding crystals built on earlier work, but by no means replaced it. Is absolute zero only of interest for crystals? The science of Thermodynamics began by Carnot was about converting between heat and work via material in the gas state. It is an important proof that absolute zero is unreachable. For gases, it is easy to prove from asymmetric heat conversion. For liquids and solids, different rules apply, there is great difficulty in converting heat to work at all in those states. Determining material characteristics at extremely low temperatures. was a significant accomplishment.