May 3, 2020 – Deep, Dark, Endless Night

Following up from last week, our universe is expanding.  Not just expanding, but at an increasing rate and no one knows if it will ever slow or even stop.

What if our universe’s expansion doesn’t stop?  Let’s take a step back and talk about energy, and entropy.

Disclaimer:  I do not pretend to understand entropy as expressed in the laws of thermodynamics.

Physicists in the mid-19th century (Carnot, Clausius, Joule, Boltzmann, Maxwell, and others) recognized that some of the energy in a system such as a steam engine, was transferred out of the system via dissipation without producing work.  Now, the person running a steam engine might say, so what?  But physicists realized this had a significance for how our world works.  Later physicists would further refine the understanding of energy transfer within and out of a system in terms of a system’s organization and stability.

So, while there is no loss of energy, the transfer processes cause a reduction of the systems organization.  A common physics class example is a glass of ice in a warm room.  Over time the ice melts and the resulting liquid water’s temperature equilibrates with the surrounding room.  A transfer of energy from the room to the ice resulted in a reduction of organization as ice crystals became liquid.  The overall result is a more stable condition in the room as air and water are in equilibrium.  Less organized but more stable.

This concept is generally known as entropy, but there is so much more to it, not suitable for my brain or this column.

Think of it this way, it takes energy to keep things organized, like your closet, and our universe is one really-big-thing!  Entropy is the result of energy transfer where energy gets spread over a larger space.  In theory entropy always increases. Locally it might decrease as energy is injected or produced but in the big picture as energy gets spread thinly entropy increases.

A mysterious form of energy we call, for no better word, dark energy (DE), is thought to be driving the acceleration of our universe’s expansion rate.  Some say this will result in a universe at equilibrium (in trillions of years). No star formation, ice melting, closet organizing.  Everything will eventually vaporize, even atoms, neutrons, protons.  Will all that remains be energy fields and elementary particles?  Will it be a quantum universe, vacuum energy, absolute zero?

Will all physical existence end this way?  Will it end as a Deep, dark, endless night?

The steam engine operator might say, so what?  Physicists argue possibilities.  I scratch my head.

As the Beach Boys said, God only knows…