Philosophy of Science

Anyone know what the Coulomb Barrier is? Fear not, because that is what I am presently going to write about…

The Coulomb Barrier, named after the physicist Charles de Coulomb, is the electrostatic energy barrier of a nuclei, a barrier which must be breached by a nuclei of like charge in order for nuclear fusion to occur.

Now, classical (read post Newtonian pre Maxwellian) deterministic physics does not allow the fusion of like-charged particles and, though less obvious, neither does Qunatum Mechanics (though with probabilistic undertones that I will get into shortly): the reason we don’t fall through the streeet and end up on the underside of China is essentially because of the Coulomb Barrier between the electrons in our bodies and those comprising the street we are walking on. The point of this rambling is that the fusion taking place in our very own sun is the fusion of single like-charged protons (and a single neutron) comprising the nuclei of two hydrogen atoms in order to form the more complex nuclei of helium. So the obvious question is ‘how do the hydrogen nuclei overcome the Coulomb Barrier in order to initiate the fusion process?’ Well, the answer is that they don’t, probabilistically speaking. Even with the awesome velocities of these nuclei due to the extremely higfh energy environment only about one in one billion potential collision scenarios (these events are called ‘quantum tunnelling’ by the way) actually succeeds in the fusing of two protons in order ot garner a helium atom. What is most astonishing is that this is the same figure that quantum mechanics predicts (given quantum indeterminacy, mind you) should occur on average. And, most importantly, this is the exact figure required to sustain the fusion process (until the sun goes red giant, that is…)

What are the conclusions to be drawn from this? What does this situation say about the laws of physics? More pointedly, what does this say about the structure of the laws of physics? Namely, if we lived in a completely deterministic universe with laws that disallowed margins of error and probabilistic indeterminacy of the metaphysical as opposed to the epistemic sort, then the Coulomb Barrier would disallow the possibility of fusion and, more essentially, if the Coulomb Barrier (interpreted fully deterministically) represented an actual law of nature (a bonafide universal constant, that is) then fusion would not, and physically could not, occur. It is only because of the indeterminate state of fundamental particles that fusion can occur.

So, does the probability exist in our interpretation of the behavior of fundamental particles or does it rest within the structure of the universe itself?