(First posted on the old Qulog, on Thursday 23rd februari 2006 – 11:05:34 PM)
As promised, although a bit late, the second part of my comparison between Intelligent Design and Quantum Mechanics. I’m afraid there’s no real compelling conclusion, so that’s left as an exercise to the reader.
Einstein famously said he didn’t like QM because “der liebe Gott würfelt nicht”: God doesn’t play dice. And I think many ID-proponents would agree.
While I was thinking about the analogy between ID and QM (see part one), I figured something else was important, something to do with chance, or probability, and with – let’s say world views. Very short version: QM’s problem with chance seems to make it fit in certain world views (like ‘new age’), while ID is a solution to a world view’s (usually christian) problem with chance. The chance aspect of QM is embraced by some people as a way to reconcile physics with things like free will and even telepathy, while ID adds purpose to the ‘blind chance’ of evolution to reconcile biology with a Creator.
In part one, I talked about ID and QM having two mechanisms for change: a continuous evolution and discrete jumps. In QM the Schrödinger-evolution is the ‘normal way’ the state of a system changes, and it is a deterministic way. That is, if you know the state of a system at some time, and you know the interactions that system has with the surroundings, say what the electrical potential is and so on, then you can just plug everything into the Schrödinger equation and calculate the state of the system at any other time, in history or future. (In principle, at least.) Chance doesn’t arrive until you decide to measure something, or predict the outcome of a measurement.
Then the continuous evolution is replaced by a jump. In general, the state of the system we’re talking about will not have one definite value for the quantity you’re about to measure. For instance, imagine the system to be an electron that you set out flying through a grating. After passing the grating, you want to know where it is, so you have set up a screen with some coating that will light up when hit by an electron. The state of the electron, however, will not be an ‘eigenstate of position’, that is, it doesn’t have one position. There are several possible outcomes of a position measurement, and the only thing that the state can tell you, is the probability density, that is: which positions you may find, and what the chances are for each.
This it does very well, as may be verified when you shoot not one, but a whole bunch of electrons unto such a screen, and they fall into the predicted pattern: many where the chances were big, few where they were small. But when you perform just one measurement, on one electron, you’ll of course only gonna find one position. Which one? You don’t know. At this point, when a measurement is done, the wavefunction (or state) is said to collapse into one of the eigenstates of the measured quantity: one of the states that do have a definite value for position, or whatever it is you are measuring. And of course, that value is what you will find – if your measurement is any good.
So, the way in which a system changes over time is completely determined by the Schrödinger equation, and can be (in principle) predicted as accurately as you like, but as soon as there is a measurement, dice are rolled and the outcome can not be predicted other than statistically.
This is all very different from what happens in ID. At first, it may even seem the complete opposite: the evolution is where chance plays a role, it’s one big life-casino, as it were, while the jumps, the design steps, have nothing to do with chance.
However, in QM the choice is between determinism and pure chance, between in principle predictable and principally unpredictable. In ID, it’s between purpose and blind chance, between design for a reason and random changes.
So, if I try to describe what happens in ID, analogous to the story about QM above (but shorter, and less well-informed) it would be this. The normal way that nature changes is through Darwinian evolution, that is, random changes will occur now and then in (the genetic material of) some organisms, and when and if these random change turns out beneficial to them, they may produce more offspring, some of which will have these same new traits. This more or less continuous evolution is replaced by a jump in the case of – let’s say radical change. A new species, for instance.
The idea (I think) here is that parents and children are always of the same species, obviously, so no matter how many generations, you cannot ‘leave’ one species and arrive at another. Which reminds me of a friend who said: you live at walking distance from the park, and so do I, so we live at walking distance from each other. Eh, yeah, but if you stick to that, than China is at walking distance from here. And that’s not what I understand by walking distance. Anyway, at some point, someone decides a new species (or another ‘major step’) has to be designed and does so, intelligently.
So there it is: chance and worldviews. Isn’t it funny how some people prefer to view the world as governed by ‘freedom-ginving’ chance instead of cold determinism (how free are you, exactly, when your thoughts are governed by dice?), while others are more than happy to add some external purpose to chance?