Why is there so much symmetry in nature? I shared some examples in an earlier post, and questioned whether there was a link between these and the ‘fine-tuning’ of the universe. I asked Francesca Day, a PhD student at the University of Oxford, if she could investigate. Francesca’s own work is on the astrophysical signatures of dark radiation, and here she explains why she thinks symmetry might lead to a more wonderful explanation of the universe than the mystery of fine-tuning.
Many argue that if the laws of physics had been just slightly different, life – or at least life as we know it – would not have been possible in the universe. The fundamental laws and parameters of physics seem to have conspired so as to make the formation of life possible. To many it seems as if science is pointing to a designer of the universe who set all these parameters just right for us – as if science is pointing the way to God. Continue reading →
Why is there so much symmetry in the world? Sea urchins, jellyfish and other animals that sit still or float around gently have radial or rotational symmetry, so they look the same if they are rotated around a central axis. All other animals – the ones that move around – have bilateral or mirror-image symmetry.*
Flowers often have rotational symmetry, and most leaves have approximately bilateral symmetry. Five-fold symmetry is found in both plants (for an example, cut an apple in half across the core) and animals.
Symmetry can be seen in astronomy, and it is also important in chemistry – biological systems which use a specific molecule often cannot use its mirror-image. We find symmetry attractive, and people we think are good-looking tend to have very symmetrical faces.
I think that the beauty seen in science falls into four broad categories. First, a scientist may find beauty in their experimental system, whether it is a model organism, a certain diagnostic printout, or an aesthetically pleasing series of molecules. Secondly, there is the cleverly devised experiment carried out with skill and patience that results in good clear data: the molecular biologist’s sharp DNA bands on a gel, the organic chemist’s high yield, or the physicist’s precise measurements. Third, the data and the theory that gathers them into a coherent whole may have an intrinsic beauty that is both striking and satisfying. Physicists have appreciated beauty in symmetry, in order, and in complex systems that are reducible to a series of ‘elegant’ mathematical equations. Biological systems are more complex and difficult to describe mathematically, so the beauty observed in the life sciences is more often to do with colour, pattern, shape, movement, or detail. At times, complex biological systems are understood at a level that does reveal their mathematical simplicity. When order emerges out of apparent chaos biologists begin to use words like ‘striking’, ‘beautiful’, and ‘astonishing’. If a theory is developed that can be used to predict further experiments and explain other data, that is also beautiful in its own way. We appreciate the order, unity and simplicity that it brings to our understanding of the world. Continue reading →