Brownian Movement and molecular reality

Beautiful coffee

beauty in a coffee, coffee beauty

Interference patterns on bubbles in a coffee cup.

In the UK Science Museum’s library there is a book, written in 1910, by Jean Perrin called “Brownian Movement and Molecular reality”. To some extent, there is nothing surprising about the book. It describes a phenomenon that occurs in your coffee cup and the author’s own attempts to understand it. Nonetheless, this little book is quite remarkable. It is perhaps hard, from our perspective in 2016, to imagine that at the time of Perrin’s work, the idea of the existence of molecules in water was still controversial. It was even debated whether it was legitimate to hypothesise the existence of molecules (which were, almost by definition, un-detectable). However, none of that is really relevant to the question confronting today’s Daily Grind. Today, the question is how can this book help us to find beauty in a coffee cup?

What does a one hundred year old book have to do with finding beauty in a coffee cup? Perrin received the Nobel Prize in 1926 for his work establishing the molecular origins of Brownian motion and, associated with it, his determination of the value of Avogadro’s constant. It is perhaps why he wrote the book. (The experiment that he used to do this is described in a previous Daily Grind article that can be found here.) It is in his description though, both of the theory and the experiments involving Brownian motion that this little book is relevant for today. One word repeatedly crops up in Perrin’s description of Brownian motion. It comes up when he describes the theory. It comes up when he describes other people’s experiments. It comes up when he describes bits of the maths of the theory. The word? Beautiful*.

Michael Polanyi

Michael Polanyi,
by Elliott & Fry, vintage print, (1930s),
Thanks to National Portrait Gallery for use of this image.

Throughout history, many scientists have recognised, and worked for, the beauty that they see in the science around them. In a 2007 TED talk, Murray Gell-Mann said

“What is striking and remarkable is in fundamental physics a beautiful or elegant theory is more likely to be right than a theory that is inelegant.”

So it is interesting that, although we may agree that scientific theories can be “beautiful” or “elegant”, we do not seem to have a way of quantifying what precisely beauty is. It is similar for those things that are beautiful that we find in every day life. The beauty of a sunset, or the way the light catches the ripples on the surface of a lake, these are things that we recognise as beautiful without being able to articulate what it is about them that makes them so. Instead we recognise beauty as something that strikes us when we encounter it. Elaine Scarry has talked about this as a “de-centering” that we experience when we come across beauty. Scarry writes that, when we encounter the beautiful:

“It is not that we cease to stand at the center of the world, for we never stood there. It is that we cease to stand even at the center of our own world”.¹

It is therefore quite concerning that she goes on to suggest that conversations about beauty (of paintings, poems etc) have been banished from study in the humanities “…we speak about their beauty only in whispers.”¹ This does not seem to have happened yet in science where it is still common to hear about a beautiful equation or an elegant experiment. But is there a creeping ‘ideological utilitarianism” in the scientific community? According to Michael Polanyi ²

“Ideological utilitarianism censures Archimedes today for speaking lightly of his own practical inventions and his passion for intellectual beauty, which he expressed by desiring his grave to be marked by his most beautiful geometrical theorem, is dismissed as an aberration.”²

While we may recoil from this sentiment, what do we write (or expect to read) in grant applications, scientific papers, popular science or even scientific outreach? How often is the utility of a piece of research emphasised rather than its elegance?

Earth from space, South America, coffee

Does an appreciation of beauty help with a wider understanding of justice and environmental concerns?
The Blue Marble, Credit, NASA: Image created by Reto Stockli with the help of Alan Nelson, under the leadership of Fritz Hasler

Another interesting question to ponder is whether our ability to appreciate (and discuss) beauty has wider ramifications. As many others have argued before her, Scarry suggests that the appreciation of the beauty in the world connects with our sense of justice¹. Recently the Pope too, in his great environmental encyclical, Laudato Si’ wrote³:

“If someone has not learned to stop and admire something beautiful, we should not be surprised if he or she treats everything as an object to be used and abused without scruple.”

Could it be true that part of the motivation that we need to change our ecological habits or stimulate our search for wider social justice is enhanced by our ability to slow down and appreciate the beautiful, wherever and whenever we find it?

So to return to our coffee. Is there something, anything, about our coffee or our tea that gives us such a radical de-centering experience? Can we, like Jean Perrin, appreciate the subtle beauty of the molecular interactions in our cup? Do we appreciate the moment as we prepare our brew? Or are we ideological utilitarians, seeing in our cup just another caffeine fix?

 

* Technically, the book in the Science Museum Library is a translation of Perrin’s work by Frederick Soddy. It is possible that it is Soddy’s translation rather than Perrin’s work itself that uses the word ‘beautiful’ repeatedly. It would be interesting to read Perrin’s book in its original French.

I would like to take this opportunity to say thank you to the Science Museum Library for being such a valuable resource and to the staff at the library for being so helpful.

 

“Brownian movement and molecular reality”, Jean Perrin, translated by F. Soddy, Taylor and Francis Publishers (1910)

1 Elaine Scarry, “On Beauty and Being Just”, Duckworth Publishers, 2006

2 Michael Polanyi, “Personal Knowledge, towards a post-critical philosophy” University of Chicago Press, 1958

3 §215 Laudato Si’, Pope Francis, 2015