What's the Buzz? The BZ reaction

The Belousov Zhabotinsky oscillating chemical reaction is the reason I ended up in a graduate program because I learned about it in one of my upper division mathematics courses : the geometry and dynamics of chaos. Oscillating reactions tie together cool mathematics and chemistry.  We'll get to heart of the  mechanism and math later, but here's an intro.

Here's a sweet little vid from youtube. This reaction is able to sustain oscillations for up to an hour depending on the recipe. The oscillations and spatio-temporal patterning that you see is the state of one of the chemicals in the system, the catalyst Ferroin. Feriin which is blue can be reduced (given an electron) to form Ferroin which is red. The red Ferroin can in turn be oxidized back into Feriin.
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 If you stir the reaction, the reaction oscillates in time, which in this particular reaction mixture has a period of about 20 seconds. ( 2 video seconds * the time-lapse rate of about 10 x).  At 0:56/3:47 in the vid,  the stirring is stopped, and you can see the patterns start to form in space. This happens where symmetry is broken in the system. A little bit of dust or a local fluctuation in concentration of the chemicals at one point in space makes that point in space just different enough from its neighbors to trigger a wave.

You see about thirty of these points to start out-- more appear later, and as the video goes on you see that some of them oscillate at different frequencies, which you see as how close the waves are together.  The ones with small wavelengths will win and kill off the ones with larger wavelengths. Another feature that is neat in this system is phase wave which shows up at 1:02/3:47, see the fast propagation of blue through the system? Ultimately, the spatiotemporal pattern formation will stop as the system comes to equilibrium and dies.

Many research groups use the BZ. Some use it to look at pattern formation and dynamics. Shout out to the Solomon Lab at Bucknell who uses the BZ to look at chaotic mixing. And the the Steinbock group in Florida who has their own youtube channel.  Some people focus more on the materials aspect. If you put the BZ in a gel, you can couple the chemical oscillations to the mechanical ones, many people are working with different aspects of this, but MIT has a nice video for you. We use the BZ a couple of different ways in our lab and on campus with some nice basic research into dynamics as well as a some applied work for patterning of neurons and the heart.