Life seems to define bodies that move with a self-directing intention we call consciousness.  At first glance, it can seem that life, which is exactingly organized, violates the natural tendency of systems toward entropy.  This tendency is known as the second law of thermodynamics.  Of course, when we dig in a bit, we realize that this thermodynamic law only applies to closed systems, and the biosphere of Earth is simply not a closed system.  

Indeed, life on Earth is the continual recipient of energetic light pressures from the sun:  plenty of fuel to keep us organisms comfortably propagating for eons to come.  But is there a closed system to which living bodies do belong?  If so, then 

life must be creating more entropy externally than it subtracts internally through its seemingly inexhaustible layers of complexity.   

It is, however, quite difficult to find a local closed system to which life belongs.  It seems that the solar system itself receives electric, magnetic, gravitational, and photonic drive from its surroundings as well.  However, if we zoom out to the entirety of existence, we can begin to make sense of the second law of thermodynamics as it relates to life. 

Let’s assume the universe is defined by all of the materials in existence with respect to the space between them.  This leaves us with the necessary concession that there is no outside to that system; and without an external source of energy there can be no input power.  At the same time, the universe as defined cannot actually lose energy either since there is nothing external to sop up motion.  The gravitational cohesion of matter seems to support this idea, such that materials appear to coalesce at least as much as they dissipate.  Some go further to speculate that gravity will eventually override galactic recession and existence will suffer a “big crunch”.  

Under these apparent conditions, the universe very much begins to resemble a classical thermodynamic system.   Since we can safely assume the laws of thermodynamics to be inviolable, insomuch as we’ve never witnessed an exception, the only possibility remaining is that life externalizes more entropy in the universe than it takes away via its own thorough self-organization.  This notion has been called the law of maximal entropy production by Rod Swenson, although the idea has been stumbled upon by many others under various guises.  

However, it seems that as our universe naturally rushes toward maximal entropy as the second law would suggest, it hits a speed limit.  At some point the production of chaos can only unfold so fast through basic chaotic dissipation of elements.  Here, 

in order to break through the rate-limiting entropy barrier and churn the environment more efficiently, the universe begins to retain chance structures which actually facilitate and hence promote chaos.  

We living beings are the product of this evolution.  MIT’s Jeremy England made headlines by testing this notion in simulations, though the logic seemed solid without such a demonstration. 

Indeed, it seems that if consciousness is merely a living being’s awareness of its surroundings, then this quality can be seen in all lifeforms.  Even the most minute bacteria are capable of orienting themselves to their trophic surroundings, exhibiting a hyper-primitive level of conscious awareness.  If we consider the physical meaning of life to be the maximally efficient production of this external entropy, then consciousness is merely a necessary tool for executing of our physical purpose: deconstruction of our surroundings.  

In fact, by tearing down our environments during metabolism, humans externalize more heat per unit volume than the sun.  

This is a consequence of Galileo’s Square-Cube law, which relates how increase in size does not affect increase in volume and surface area equally.  Because bodies can only dissipate heat through their surfaces, which vary as a function of their length squared, and heat is generated as a function of volume or length cubed, a large body like the sun can only give off a small portion of its heat at any given moment. 

So while the sun is hotter than a human it dissipates less heat per unit volume.  We are, in fact, extraordinary little dissipation machines.  Our consciousness appears then to be a mandatory bit of software necessarily evolved to meet the demand that our physical existence depends entirely upon the maximally efficient location and deconstruction of our surroundings.  So yes,

physics can explain consciousness as the process by which life is oriented toward its indisputable physical duty:  the maximally efficient disassembly of its surroundings.