Evolution is still all too often (but wrongly) downplayed as “just a theory” in public discussions. This is partly due to an unfortunate misunderstanding of what a theory means in science, as opposed to its common language meaning. Evolution by natural selection is much more than just a hypothesis, and is as much a valid and well-accepted scientific theory as the theory of gravitation. What Darwin did for biology is on par with what Newton did for physics — and mathematics plays an important role in both theories.

Read the full article in Plus magazine…

Last night a rare event happened: the summer solstice and a full moon at the same time. So I went up Kahlenberg, a hill above the city of Vienna, to have a good view of this special full moonrise. Unfortunately my cheap little point-n-shoot camera is almost useless in low-light conditions, but I got a few halfway decent shots anyway. Click each pic to see a larger version.

Continue Reading

I’ve made a short movie showing autocatalytic sets arising in a dynamical simulation of a simple polymer model. It shows how autocatalytic subsets appear, one after another, and then grow in concentration. This provides a nice visual and dynamical example of our usually more graph-theoretical analyses. Continue Reading

A key result of last year’s UN climate change conference in Paris is that we now have a new international deal to curb climate change. However, it seems primarily focused on reducing greenhouse gas emissions to limit global warming. A significant step forward, no doubt, but it does not address the more difficult, and perhaps also more relevant question of how to deal with the inevitable consequences of climate change. Are we able at all to predict what those consequences will be? And, more importantly, will we be able to do something to reduce, or even prevent, some of these consequences? When it comes to biodiversity and the distribution of species, some researchers believe this is indeed possible.

Read the full story on Plus magazine.

“Please hold the line, your call is important to us.” It’s a sentence we’re all frustratingly familiar with. Just as familiar as we are with standing in line at the supermarket or post office, with the other queues seeming to move much faster than the one we happen to be in. Thankfully, mathematics can help. Queueing theory studies such situations mathematically, and tries to find solutions that minimise the average customer waiting time while also limiting the average time a queue server remains idle. This double constraint makes the problem a difficult one. An additional source of difficulty is the randomness involved. Customers usually do not arrive at regular intervals, but their arrival times are what is called a stochastic process. Coming up with a general formula that provides a solution for such stochastic problems is generally difficult, and sometimes even impossible. Recently my uncle Arie Hordijk and I studied such a queueing problem, and came up with a solution based on the movements of a ball on a billiard table…

Read the full story on Plus magazine.

What is life? This question is still much debated in science. After the discovery of the structure of DNA by Watson and Crick in 1953, and the more recent advances in DNA sequencing technology, living organisms have become primarily viewed as being defined by their genes. However, there is more to life than genetics alone. In fact, a more “holistic” view is emerging in which the essence of life is considered to reside in the complex collection of chemical reactions that enable an organism to grow, repair, and reproduce itself. In other words, life as a network of self-sustaining chemical reactions. This alternative view could have important consequences for many areas of science, for example the way we might treat diseases like cancer, search for possible life on other planets or grow artificial donor organs. And now there is mathematical evidence that at least one particular living organism (the well-studied bacterium E. coli) is indeed such a self-sustaining reaction network, thus formally supporting this alternative view of life.

Read the full article on The Naked Scientists.