That was the question sung by Dr. Alban, the one hit wunderkind, who, if my poor memory serves me, washed up on the shores of Sweden in the mid-1990s. However, a more interesting answer to this conundrum has been posed by Dr. Paul Davies, an Australian astrobiologist. Davies argues that the primary quality of life is the ability to replicate information, and that this process can be viewed as a quantum phenomenon.
Viewed this way, the problem of life’s origin is switched from hardware to software. The game of life is about replicating information. Throw in variation and selection, and the great Darwinian experiment can begin. The bits of information have to be physically embodied in matter somehow, but the actual stuff of life is of secondary importance. There is no reason to suppose the original information was attached to anything like the highly customised and evolved molecules found in today’s living cells.
Therefore, the origins of life are no longer reserved for chemical structures or the complexities of single-celled organisms. Life is defined as a process for the replication of information and is not limited to one particular source.
All it takes to get life started is a quantum replicator – a process that clones bits of information attached to quantum systems by allowing them to interact with other quantum systems in a specific way. The actual system could be anything at all – the spin of an electron, a meta-stable atomic state, or a molecule that can flip between two conformations. The uncertainty inherent in quantum mechanics provides an in-built mechanism for generating variations.
The leading question from this speculation is why did replication shift towards larger and more complex structures. We are a sturdier and more stable foundation for data storage! No wonder many think that our mind children, with better memory capacity, will replace us.
Try Graham Cairns-Smiths book, “Genetic Takeover”.
Presents an alternative to the primordial soup. Again, his proposal provides an infornation carrier and a replication mechanism.
Raw information storage is insufficient. Differential replication of that storage system, based on selection, is an essential.
The problem with his definition is that it means that computers as they exist today are alive.
It also means that printing presses are alive.
Yep, SDB gets it exactly right. This is silly.
I think Aaron Haspel has a better definition. It’s hard to give in 500 words or less, but I’ll try. From the basic premise that everything is matter and everything that ever happens is an energy transfer, start with the Gibbs-Boltzmann equation for free energy:
ΔG = ΔH – TΔS >= 0
Where G is free energy, H is enthalpy, T is temperature and S is entropy. Now, the thing to remember is that S is composed of many discrete energy transactions which will be either positive or negative, and in accordance with Hess’ Law we can segregate them into positive and negative like so:
ΣH – TΣS neg – TΣS pos >= 0
We can drop G because it’s not what we’re interested in. Then we rearrange the equation a bit, adding (TΣS pos) to both sides and then dividing both sides by the same term. This gets us:
α = (ΣH – TΣS negative) / TΣS positive >= 1
The new term on the right, alpha, is a dimensionless number (the units cancel out) representing the rate at which the free energy in a system is directed toward coherence. (Keep in mind that negative entropy is good because it increases chemical coherence, and positive entropy is bad because it goes in the opposite direction.) If you were to measure this number for various kinds of physical systems, you’d find that things like rocks and machines have a significantly lower alpha number than bacteria or animals.
This gives us a good way to answer the original question: what is life? It’s some number greater than one, though in order to find out the precise value we’d have to do the sums. That can be someone else’s homework assignment. It’s bound to correspond a lot more closely to our intuitive notion of life than this Davies’ fellow’s idea.
Matt,
I have a (potentially really stupid) question, in two parts.
I’m not a physicist / math guy, but I have heard often enough that the entropy of the Universe is increasing. Has that been proven somehow, or is it “just a good theory”?
Second, it seems that life opposes entropy. Life creates order where before there was none (or less, at any rate). The Earth seems to be more ordered with each passing era, as life systems become more complex and sophisticated. So, if life spread out far enough across the universe, bringing its order-creating properties with it, could we reverse the universe’s entropy?
On Stephen’s point, I noticed that too. Computers should not be considered alive yet. They are incapable of creating & preserving information without us. His point is well taken though (and Matt’s too) that life is modality neutral, so long as information (or ‘alpha’ to use Matt’s variable) continues to increase. I would say that computers (and printing presses) have dramatically improved humanity’s ‘alpha’. Does that make us symbiotes? And if the Singularity ever happens, and there’s strong AI, etc., would humans then be beneficial, intra-organism parasites? Like mitochondria in the Earth-wide Skynet organism?
So we are artificial intelligences created by information nexuses?
Brock,
Life has been defined as “localised pockets of negative entropy”. However, this is only possible by increasing entropy around itself. Entropy increases. Full stop.
We decrease entropy locally, but only as a result of energy input, and this energy is released as a result of a localise increase of entropy elsewhere. In our case, the sun.
Water runs downhill, but the only way to get it uphill is to pump it. Utilising energy and increasing entropy by generating unusable heat.
Dave,
So we are artificial intelligences created by information nexuses?
Nope.
Nothing artificial about us, there was no designer or builder.
”Therefore, the origins of life are no longer reserved for chemical structures or the complexities of single-celled organisms. Life is defined as a process for the replication of information and is not limited to one particular source.”
If this were taken literally, aren’t we simply pushing the mystery further back. We will have to find the step from the quantum world to the first primitive RNA precursor. We’ve effectively replaced one mystery with a bigger mystery.
But I shouldn’t quibble, we need speculation like this to move things forwards. Let’s just remember this is only speculation otherwise we may end up establishing a new religion.
James Lovelock suggested to NASA that one way of looking for life on other planets would be to look for localised reductions of entropy, which could be done at a distance. They preferred to send expensive probes to Mars, which was more sexy, but his assupmtions were proved braodly correct.
Also, a computer is no more alive than a fridge, which also reduces entropy.
Also, I think Dr Alban sang ‘It’s My Life’, hence (an advertizing hence) it’s use in a tampon advert.
Brock,
Yes, the second law of thermodynamics is about as ironclad as theories ever get. As Chris Harper says, you can decrease entropy (and thereby increase alpha) locally, but taking the entire universe as a unified block, entropy always tends to increase globally. But this isn’t a big deal. A helpful analogy is to consider living creatures as being like firms in a free market — they’re all trying to maximize their profits (alpha), but there is no way to “win” the game permanently because you can always go brankrupt.
Ah bollocks. Sorry about that, still haven’t mastered the art of the “preview” button. Link.
There’s a faulty premise in this question. Replication did not simply “shift towards larger and more complex structures”. Bacteria – although still quite complex – have admirably small and streamlined genomes. Evolution includes examples of both ‘simplification and streamling’ and increases in size and complexity.
I do not think that a newspaper op-ed can go into the history of this line of thought. It begins at the end of WWII, when the great physicist Erwin Schrodinger, one of the inventors of quantum mechanics gave a lecture titled “What is Life?”, which is still in print. The great mathematician, John von Neumann, who invented game theory and computer science, inter alia, attacked the problem by creating the theory of self-reproducing automata. A later version of this theory is embodied in the Game of Life, which most computer users have played. If you haven’t: try here. More information.
“what is life” was sung by Haddaway, not Dr. Alban
We are meat machines. For the most part genetically encoded. The rest is culturally programmed as in meme, a brain to brain information transfer.
In our case its seems that being able to run with the herd a couple of hours after being born was not important. Mom had the capability to carry us around and protect us as well as herself (well maybe a man helped some). This extended period of bonding and potential for communication meant that survival clues did not have to be genetically encoded but could be culturally encoded. This greatly increased odds of survival which have not been that good for any species.
Modern man is a product of the genetic, pre-programmed meat machine and his cultural programming for survival.