August 11, 2022

I, Science

The science magazine of Imperial College

(Photo Credit: Andrew Purcell)

The way we perceive the world is inevitably shaped by the models created in our brains. As a species, we have evolved to understand the world in such a way as to maximise our survival chances out on the African savannah plains of the Pleistocene and this has inevitably had consequences in defining that which we have come to describe as ‘normal’.

Now, we all understand the concept of ‘the visible spectrum’ with regards to light. We know that there are other wavelengths of light out there, but we also know that these are either too fast or too slow for us to be able to see them unaided. The reason that our ‘visible spectrum’ is where it is on the spectrum of all wavelengths is simply because this is the range of light which it was most useful for our ancestors to be able to see. For example, if I were a honey bee, I would be able to see much further into the ultra violet end of the spectrum, as this would allow me to see the markings on flowering plants, guiding me towards the pollen they contain within.

Now, let us take a moment to consider the possibility that analogous phenomena could exist in relation to variables such as objects’ size and speed of movement. As soon as we start talking about things like the distances between stars, or the time required to travel between them, the numbers get so big that we all start to have problems grasping what these values really mean. We inevitably have to resort to invoking logarithms. Equally, in order to understand really small things like atoms, we have to invent models of solar systems with a nucleus sun in the centre, surrounded by orbiting electron planets. But, it’s really nothing like this at all! In fact, that we consider the ground beneath our feet to be solid, when it’s really just a collection of atoms interacting with each other across a void of nothingness, is really weird actually when you come to think about it! We even talk about touching things, but the atoms in your hand are certainly not in contact with the device you are using to read this blog. Mutual repulsion of electrons sees to it that no ‘true contact’ can ever be made between atoms in this way. Push as hard as you like; you cannot make two electrons come into contact. And the electrons will never touch the nucleus.

Here is a picture of a hydrogen atom, consisting of exactly one proton and one electron. In reality, the diameter of this whole atom is only about one ten millionth of a millimetre. However, if the nucleus were really as big as it has been shown here, then the electron would not only have to be about 100 metres away, but it would also still be far too small for us to see with the naked eye.

Thus, as soon as anything becomes really big or really small, really fast or really slow, we start to have major difficulties understanding it. As with light, there’s really just a narrow band of sizes and speeds which we have evolved to understand easily. Anything outside of these bands and we are, quite literally, blind.

So, what fortitude then that the same evolutionary forces driving us to become sufficiently intelligent to be able to communicate verbally and create ever-more sophisticated virtual maps in our ancestral brains of things like where the bushes with the best berries are in relation to our cave, have also allowed us to develop the intelligence to appreciate (and of course compose) the partitas of Bach, the sonnets of Shakespeare and even the Mr Blobby Song.

Perhaps the pinnacle of accomplishment, which our evolved intelligence has enabled us to achieve, is the development of the scientific method. This method has enabled us to peel back the curtains and expand our horizons just a fraction. But perhaps, one day, there will be no horizons at all limiting our understanding of the universe in which we live. On the other hand, perhaps there are things which are just too strange or too complex for our brains, evolved to help us understand what Richard Dawkins has termed our ‘middle world’, to ever fully come to terms with. To borrow a seemingly tautologous phrase, popularised by politicians Donald Rumsfeld and Jack Straw on opposite sides of the Atlantic, perhaps there will forever remain ‘unknown unknowns’.  And perhaps J.B.S. Haldane was right in suggesting that “the Universe is not only queerer than we suppose, but queerer than we can suppose”.

Even if this should prove to be true in the long run, and personally I suspect it won’t, it is thanks to science today that that which is out of sight, no longer has to remain out of mind.