The Tuning Problem in Physics

The tuning problem in physics is the question of why the constants of the laws of nature have assumed their values relative to one another that they have. In order to have a chance of answering the question we must rephrase it in a way that it could possibly be answered scientifically. That is, not why the values are what they are, but rather how it is that they are what they are. The distinction may seem subtle and unnecessary, but it shifts us from trying to assign a reason (an unscientific task) to one of understanding a process (an eminently scientific endeavour).

I say tuning problem because these constants appear as tunable parameters in the natural laws. Assuming they could assume any value relative to one another, for we have no knowledge of how they might be constrained, we find that there is an extremely narrow range in which a universe such as our own is made possible. But the term also suggests a process, one of adjustment - that of the parameters being tuned with respect to one another.

If we hold the constants as having been constant back to the very beginning of the universe then it seems any explanation will be very elusive indeed. Using our process-based methodology, we will be led to speculate about a time before the universe and thereby a universe beyond the universe. Even if we could extract answers from such a line of inquiry, ultimate knowledge would forever elude us, as this 'rabbit hole' is one of infinite depth. Then there is the possibility that time (at least as we know it) emerged with our universe, so that extracting sensible answers out of 'the time before our universe' is a fool's errand.

It seems to me that a different tack suggests itself. Instead of holding the constants as constant, we assume that they are tunable and inexorably linked to one another by feedback mechanisms. There is at the beginning of the universe (perhaps in actuality some time afterwards) either an arbitrary assignment to these constants or a unity between them or some other relationship that we can imagine and hopefully justify. As we proceed in time, a process unfolds whereby the parameters adjust themselves relative to one another until at last a universe not unlike our own is arrived at. We then need to discover and explain this process. The task appears daunting but also more promising than the route of trying to go back to before the beginning of time.

Such an approach is not new. There are many theories that take the constants of nature (or at least some of them) as non-constant during the early days of the universe. There are variable speed of light theories that attempt to explain cosmic inflation, and ideas that hypothesize a varying gravitational constant. However, simply asserting that these constants changed is not enough. What is necessary at bare minimum is an explanatory framework for how they changed. I suggest simply that such a framework may perhaps be found not by considering each of the constants individually, but rather by considering them altogether as part of a feedback mechanism.