I was lucky enough to be taught my Thermo by Hank Van Ness and Mike Abbott.  I am sad to say, that they both were better teachers than I was a student.  My grades in the subject were atrocious; but throughout my professional career I was seen as the go-to guy in when it came to VLE calculations.

Almost all engineers and scientists have some training in Thermodynamics, and almost all of us know the Four Laws of Thermodynamics.  In reality, there are only 3 laws and an assertion.  The assertion is sometimes referred to the 0th Law of Thermodynamics, and can be summed up by the statement Temperature Exists.

Everyone should be familiar with the First Law – Conservation of Energy.  As any Chemical Engineer can tell you, if you model a system and you cannot complete a simple energy balance, the model is basically worthless.  This is comparable to the mass balance.  It is so fundamental that it is to be taken for granted that any system that violates either of these truths is not to be trusted.

The Third Law, the one that states that the absolute entropy is zero for all perfect crystalline substances at absolute zero, is rarely invoked by the vast majority of scientists and engineers.  It probably comes into play for the wizards who dabble in extreme cryogenic temperatures, but for the rest of us in the room temperature realm, it matters little.

But the Second Law of Thermodynamics, that is another question all together.  The Second Law puts limits on changing heat into work.  It is the reason why perpetual motion devices can never work.  It is fundamental to our understanding as to how the universe works.

Entropy – the measure of disorder – surrounds us.  Look at your desk: the piles of papers there did not spontaneously grow by themselves.  You added to them probably until you needed to find something in one of them.  At that time, you probably spent far too long going through the papers until you found what you were looking for.  That expenditure of work – sorting through papers – was fighting the disorder that is your desk.  Of course a filing system is a method to contain entropy, but it takes effort and energy to stick to it.  Creating order out of chaos takes work and it is a constant struggle.

While there are many who can recite the textbook definition –the total entropy of any system can never decrease – there are few who understand its philosophical underpinnings.

We believe in the Second Law because we have observed it to be true.  After all, your mug of tea does not spontaneously warm up as it sits on your desk, just as your can of Coke does not get colder without some outside influence.

Of course, we see this in the expanding universe.  As the universe expands, disorder increases.  This is not rocket science, it is common sense.  There are some hardy souls in the astrophysics community who are on the search for “dark matter”.  Seems the visible mass floating around out there is not enough to eventually slow the expansion of the universe.  If they can find enough of the missing mass, there might be some point at which the universe would begin to collapse to a new singularity, followed by another “big bang”.

If there is enough mass for the universe to begin contracting, wouldn’t that violate the Second Law?  A contracting universe would imply a spontaneous decrease in the entropy of the entire universe.

So the question boils down to: Is the Second Law of Thermodynamics truly a universal Law, or is it a byproduct of an observable expanding universe?

If it is indeed a universal law, then the search for “dark matter” is pointless, because there will not be enough mass to induce the universe to contract in on itself.

However, if sufficient “dark matter” can be found to ensure the collapse of the universe to a new singularity, then the Second Law is simply an artifact of observation.

It will be interesting to see what develops.