I’m currently writing about energy, and I keep coming up against the concept of negentropy or negative entropy, and I just don’t get it. So it would be great if someone could explain it or point to a good URL. So far the urls don’t explain my issues away.
You will all probably know the background ‘laws’ of thermodynamics of which two are particularly important.
0) Left to itself heat flows from a higher concentration to lower concentration. If two thermodynamic systems are each in thermal equilibrium with a third, then they are in thermal equilibrium with each other.
1) Energy can neither be created nor destroyed. The total energy of the universe remains the same.
2) Any use of energy will result in energy being dispersed and becoming unavailable for use. This is entropy. The entropy of an isolated system [that is a system with no external source of energy] will tend to increase over time [and eventually cease to function].
Entropy is a process, not a thing. It is generally said to be irreversible. As a result, entropy marks time.
The question is what is the use and validity of the idea of ‘negentropy’. People seem to talk about the ‘consumption of negentropy’, which does not make sense to me at all. You cannot consume entropy, so why can you consume its ‘negation’? Are you violating the first law, which says energy cannot be created?
I’m assuming that negentropy arises because people want to make entropy equal to disorder, hence there is a problem of apparent increasing order as with life Life appears to build more and more complex order and repairs itself. (I think Schrodinger invents the term ‘negative entropy’ to solve the mystery of life.
“[an organism can only keep aloof from it, i.e. alive, by continually drawing from its environment negative entropy – which is something very positive as we shall immediately see. What an organism feeds upon is negative entropy”What is Life p,71).
He goes on to ‘explain’:
If D is a measure of disorder, its reciprocal, 1/D, can be regarded as a direct measure of order. Since the logarithm of
IID is just minus the logarithm of D, we can write Boltzmann’s equation thus:
- (entropy) == k log ( riD) .
….. entropy, taken with the negative sign, is itself a measure of order.ibid: 73
I don’t like to think that I’m saying Schrodinger is talking bullshit as its hardly easy to justify, and in his defense there seem a large number of different interpretations of what he said.
What seems to be the case
However, there is nothing in the laws of thermodynamics, which says that with an external energy source, ‘processes’ cannot build what appears to be order, or even temporarily make a place exceedingly orderly. All that seems to be required to be recognised is that the building of order, or regeneration etc., takes energy and disperses energy. so all of that energy is no longer accessible to the system. That is it. Energy is used and dispersed to make order. No need for negentropy, or consumption of negentropy, at all.
After a while, it takes more energy to keep the organism or information going, and it eventually breaks down (unless its a bacteria perhaps, but its not the same being after it has split many times). Again, this is connected to the Second Law in that energy is dispersed in attempting the order, and if something gets way too complicated it can take more and more energy to maintain, and run out of access to enough energy to maintain, and therefore starts breaking down.
Over time, the organism (or an information string if you want to tie entropy to information) tends to fail to replicate properly – there is not enough energy available to each complex organism to ensure that every replication is accurate all the time. Likewise it takes less energy to make up bullshit than it does to make up accuracy. This failure to replicate accurately can lead to evolution if failures prove ‘useful’ to further replication.
Maxwell’s demon sometimes seems to get tied in with negentropy. You all know this involves an imaginary creature opening and closing a door to let gas particles accumulate in one side of a box. The demon’s actions take energy, for it to observe, and for it to open and close the door against friction and inertia. There is no apparent mystery. The box gets organised because the ordering takes and disperses energy.
So what does the idea of negentropy add to anything?
A Social science example
Let me quote:
Our main thesis is that the Anthropocene can be described as an Entropocene, insofar as the contemporary period is above all characterized by a process of the massive increase of entropy in all its forms (physical, biological, informational).Internation. Letter to Antonio Guterres
In 1945… Lotka showed that the production of knowledge is the condition of the struggle against entropy for this technical form of life that is human life.Internation: General Introduction
The general implication is that we must organise to defeat entropy and that life is negantropic.
However, entropy is a measure of dispersal of energy. The more energy is dispersed or wasted, the more likely that we won’t have enough energy to fix things up as they fall apart or get stressed. Therefore we need to make energy usage as efficient as possible, with as little loss as possible. Something no one aims at when energy is plentiful.
Making energy usage efficient does not stop energy being dispersed and entropy increasing. It is not negative entropy, it is not demaking entropy or consuming entropy, it just tries to make energy dispersal as minimal as possible.
Schrodinger tries to clear up his problem, saying
The remarks on negative entropy have met with doubt and opposition from physicist colleagues. Let me say first, that if I had been catering for them alone I should have let the discussion turn on free energy instead.What is life p 74
Free energy as I understand it is easily available energy, which can be extracted by the application of energy. For example, it takes energy to find food, eat it and digest it. So food, in general, has to provide an organism with more energy that it takes to find it, eat it and digest it.
He also says
And that we give off heat is not accidental, but essential. For this is precisely the manner in which we dispose of the surplus entropy we continually produce in our physical life process.
Digestion and the uses of food energy to power and repair the body, disperses energy. There are other things going on as well such as maintenance of the body between a small range of temperatures. In other words all he requires is normal transformatio of energy.
Negentropy seems largely to arise, because he wants a direct equality between disorder and entropy, rather than an indirect and complex connection