Janet Eniraiyetan (Laidlaw Scholar), BA Philosophy & Physics

The Double-slit experiment demonstrates the indeterminate nature of quantum systems such as photons, electrons and all subatomic particles. It shows that we cannot attribute the wave picture or the particle picture alone to a photon. This is because, to attribute the wave picture, the photon must always have a wavelength, which it does not. Similarly, to attribute the particle picture alone, the photon must always have a single position, which it does not. This difficulty leads us to what is known as the Measurement Problem - the notion that we are unable to reach a definite conclusion on the nature of a quantum system as there are different fundamental laws describing the system before and after observing/measuring the system. From this, we must conclude that the position of a photon is indeterminate before observation.

But how does this indeterminism affect our understanding of reality? And is this indeterminism of the world itself or due to human limitations?

Looking specifically at how two different philosophical theories, Quantum Metaphysical Indeterminacy and Fragmentalism interprets indeterminism, I assessed the strength and weakness of each interpretation and found that our understanding of reality is flawed. However, quantum mechanics shows that the idea of real metaphysical indeterminacy, one which has no epistemic or semantic limitation plays a genuine explanatory role in our understanding of reality.