Does biology violate the second law?

Question

Are the growth of an organism and the evolution of life exceptions to the tendency of natural processes to become more disordered?

Answer 1

There tends to be a lot of misinformation floating around about the Second Law of Thermodynamics.

Biggest myth: "The 2nd Law only applies to closed systems".

This could not be more wrong. It applies EVERYWHERE. The specific form of the equation describing the relevant thermodynamic variables will change depending upon what type of system you apply it to (see below), but the general form of the 2nd law applies everywhere.

Let's get down to the science. You're asking about biological systems that grow. A biological system takes in heat and mass, and releases heat and mass. In thermodynamic parlance, this is an "open" system. Here are the definitions of thermodynamic systems:

open: permeable to heat and mass transfer
closed: permeable to heat transfer
isolated: not permeable to heat nor mass transfer

Here is the Clausius form of the 2nd law for isolated systems: "The entropy of an isolated system not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium." And this is all well and good, but we're dealing with biological systems which are OPEN systems, not isolated systems. So what is the general form of the 2nd law applicable to all systems?

Here it is, the Clausius inequality:

dS ≥ dQ / T

where S = entropy, Q = heat transfer, and T = temperature, and 'd' is the derivative operator in calculus. Note that this inequality states that entropy flows with heat. For an isolated system, Q = 0 by definition. You can see that Clausius' statement above indeed does hold for isolated systems, since in this case dS ≥ 0 which means that entropy will either stay the same or increase in an isolated system, but never decrease. Again, while the general form of the 2nd law applies to all systems, it reduces to dS ≥ 0 for isolated systems only.

However, for open systems such as biological cells, tissue and organisms, Q is non-zero. These systems exchange heat and mass with their surroundings, and by virtue of the Clausius inequality that also means that entropy can flow in and out as well (entropy flows with heat). The implication for biological systems is that they CAN become more ordered as a natural process simply because they can exchange entropy with their surroundings, and this is completely in accord with the 2nd Law of Thermodynamics. If dQ is negative for an open system (heat outflow), then dS can be negative as well (reduction in entropy). There is no thermodynamic violation. In fact, biological organisms only reaffirm the validity of the 2nd Law of Thermodynamics.

Answer 2

There are many local violations of the Second Law of Thermodynamics; the Law applies to a closed system over a period of time, and since a biological system is not closed, it is largely exempt.

If, however, you place ice cubes in a container of bowling water, and have some way of excluding both heat and cold from outside sources, the entropy of said water would increase over a period of time, so that no further activity was possible.

But, as you can see, that is actually a very special set of conditions...and is largely a convenient fiction.

Answer 3

Lancenigo di Villorba (TV), Italy

YOU WROTE BAD!
Biological remarks OBEY TO THE "Thermodynamic's Second Principle"!!!
AMONG THE MEN PRECEEDING ME, SOMEONE TRIED TO ADAPT THE MATHEMATICAL TERMS DEFINED BY CLAUSIUS.

ABOUT 2nd PRINCIPLE
A german physician, R. J. Clausius, stated a well-known affirmation :
"Entropy is a Thermodynamics System's Function related to Heat's Exchanges passing through the CLOSED System's Boundaries ; at differential level, it may write

d[S] >= d[Q] / T

where d[.] is the Differential Operator, S is Entropy, Q is Heat's exchanged and T is Boundary's Temperature".
Furthermore, Clausius himself stated :
"Any ISOLATED System cannot exchange any Heat's Amounts, hence ITS ENTROPY's VALUE CANNOT DIMINUTE."
IF I THINK BIOLOGY AS AN ISOLATED SYSTEM, I MUST ASSUME d[S]biol >= 0.

ABOUT EARTH's ENTROPY
I MAY THINK BIOLOGY AS A CLOSED SYSTEM, because Earth Planet represent the entire ensemble of its Biological Habitats : this portion, the Whole Portion, is exchanging Energy instead Matter.
I must start from Clausius statements, nonetheless I evoke other statement one about Entropy. The american physician J. W. Gibbs introduced its "Differential Disequations" (in a second time modified by a scothish physician, J. C. Maxwell) among those there is the following one

d[E] =< T * d[S] - p * d[V]

where E is Inner Energy of the System, V the volume occupied by the System and "p" is the Pressure's Value at the Boundary System. As in the previous writing, this differential relation interests ONLY the Closed Systems, that is the System CANNOT exchange matter across its boundaries. Hence, at differential level I offer an estimation of smallest Entropy's variances related to any phenomena running in CLOSED Systems

d[S] >= (d[E] + p * d[V]) / T

In any instant, Earth Planet soaks Energy from the Sun
(e.g. d[E] > 0) while its volume is maintained (e.g. d[V] = 0).
IF I THINK BIOLOGY AS A CLOSED SYSTEM, I may rescue
d[S] >= d[E] / T > 0.

LIVING's ENTROPY
Among living systems there are "Microrganismes", e.g. molds, bacteria, etc. I may think to a simple microbe-system constituted by two Microrganismes Strains leading to
PREY-PREDATOR MODEL.
PREY is a simpler microrganismes taking Organic Carbon and Energy by the Medium while PREDATOR is a more complicated one, it is able to eat the PREY. At differential level, lab's data (see colonial units) agree these differential writings

d[Food]/d[t] = 0 - k1 * |Food| < 0
d[Prey]/d[t] = k1 * |Food| - k2 * |Prey| * |Predator|
d[Predator]/d[t] = k2 * |Prey| * |Predator| - k3 * |Predator|

This is the SIMPLEST MODEL among many other ones ;
I can rescue some informations :
-) in the short-time period, PREY and PREDATOR are continuously increasing bother, despite FOOD ;
-) in the middle-time period, PREY begins to disappear because PREDATOR becomes greater and greater number ;
-) few times later, PREDATOR begins to disappear because PREY join to its minimum ;
-) finally, PREY rise to greater values during PREDATOR's death.
By sketching these evolutions in a PREY vs. PREDATOR's Chart, I study a differential form belonging to TOPOLOGICAL CLOSED CURVEs. These mathematical results state that PREY-PREDATOR SYSTEMs COLLAPSE ON THE LONGER TIME-PERIODs BECAUSE LACKs OF FOOD or ASSIMILABLE CARBON-SOURCEs.

I hope this helps you.

Answer 4

I just add that none of the laws of thermodynamics have ever been broken.

Answer 5

I see it as a major violation.