The Renormalisation Group

A new video which more or less completes the critical phenomena series. Jump straight to it if you want to skip the background. One of my favourite topics is the critical point. I’ve posted many times on it, so to keep this short you can go back here for a summary. In brief, we’re looking at a small point on the phase diagram where two phases begin to look the same....

April 25, 2012 · 5 min · Douglas Ashton

The thermodynamic limit

This post has been at the back of mind for a while and written in small, most likely disjoint pieces. I wanted to think about connecting some of the more formal side of statistical mechanics to our everyday intuitions. It’s probably a bit half baked but this is a blog not a journal so I’ll just write a follow-up if I think of anything. I’m often accused of living in a rather idealised world called the thermodynamic limit....

April 18, 2012 · 7 min · Douglas Ashton

A phase diagram in a jar

One of the things I love about colloids is just how visual they are. Be it watching them jiggling around under a confocal microscope, or the beautiful TEM images of crystal structures, I always find them quite inspirational, or at least instructional, for better understanding statistical mechanics. Sedimentation Just to prove I’m on the cutting edge of science, I recently discovered another neat example from 1993. At the liquid matter conference in Vienna Roberto Piazza gave a talk titled “The unbearable heaviness of colloids”....

November 7, 2011 · 3 min · Douglas Ashton

Universality at the critical point

Time for more critical phenomena. Another critical intro I’ve talked about this a lot before so I will only very quickly go back over it. The phase transitions you’re probably used to are water boiling to steam or freezing to ice. Now water is, symmetrically, very different from ice. So to go from one to the other you need to start building an interface and then slowly grow your new phase (crystal growth)....

July 9, 2011 · 3 min · Douglas Ashton

Colloids are just right

All being good it looks like I’ve secured employment for a tiny while longer. Hooray! The place I’m moving to is a big place for synthetic colloids, so it seems like a good time to go through what I know about colloids. If nothing else it’ll be interesting to compare this to what I’ll know in a year’s time! So, here is a theorists perspective on colloid science. I’ll spare the usual introduction about how colloids are ubiquitous in nature, you can go to Wikipedia for that....

February 3, 2011 · 6 min · Douglas Ashton