newsletter November 2008-December 2009 from www.flyingcircusofphysics.com

Maybe you can help on this matter: Certain, potentially lethal bacterial infections produce a red line, marking the infection’s location and progress, much like a line on a graph. The red line might start low on a leg at the initial site of the infection and then travel up the leg. If the infection reaches the heart, the damage to the heart can be lethal, and so the march of the red line toward the chest is a sign of acute danger.
Here’s my question: What factors determine the rate at which the red line progresses? It is not at the speed at which blood flows through the veins. Is it, instead, the speed of a gradual diffusion of the bacteria through the muscular regions?

With the holiday seasons approaching, I hope that you might consider The Flying Circus of Physics book as a gift to give. There are also many more books displayed in the Store section of the FCP web site --- the links there are to Amazon.com in the United States. The books range from sports science to cooking science to traditional physics subjects (such as special relativity). Here are two excellent choices:
1. The Self-Made Tapestry: Pattern Formation in Nature by Philip Ball. It explores (without equations) how patterns, even complex patterns, occur in natural settings, something that fascinates me. In fact, show a naturally occurring pattern to any scientist, and the heart rate measurably increases. This book is jam-packed with examples along with their explanations (at least as currently understood --- this is ongoing science for many researchers).
2. Einstein’s Dreams by Alan Lightman. Each chapter in this slender book is a story about how people would live if the nature of time were different or if the curious aspects of time in Einstein’s general theory of relativity were more apparent. The book is highly acclaimed and even beautiful, based on hard-core physics but as delicate as a poem. It is a book I reread frequently (and dream about).

At the FCP site for December and January, I’ll post my two Scientific American articles about using polarizing filters (such as from polarizing sunglasses) to transform the polarization of sky light into colors, so that you get a sensation of what some polarization-sensitive insects see when they navigate by using the polarization of skylight. Many of you can actually detect the polarization of light with just your eyes, without the need of a filter. I explain how.

Here are some of the subjects coming up at the FCP site:

1. Fireflies are the summertime insects that briefly emit light. Such light emission is interesting because it is “cold,” that is, it occurs with no loss to thermal energy, in contrast to other sources of light. However, even more interesting are the swarms of fireflies that will lock-step their flashing, so that, say, a nighttime riverfront will flash on and off with firefly light, as if the riverfront was rigged with advertising lights. How do the fireflies flash in synchrony?

2. Tornadoes have both horrified and intrigued me since I was a child growing up in Texas. Indeed, I have often imagined what I would see if caught in a tornado. I can only imagine that it would be an utterly helpless situation, where survival depended only on chance, and yet some people have recorded videos of the experience, as I shall describe. Here is a basic question. When a tornado moves down your street, blowing out your windows, do the windows blow inward or outward?