Stephen Chu’s White Roof Proposal and Rush Limbaugh’s Response

White roofing on urban row homes in Philadelphia

White roofing on urban row homes in Philadelphia

It does not surprise me that Rush Limbaugh would think that Energy Secretary Stephen Chu’s proposal to paint flat roofs white is idiotic, but I found it rather amusing that he couldn’t even figure out how reflection works on his radio talk show this morning. This is a very simple idea, light colors are brighter or lighter than dark colors because they reflect more light. The key is to understand that light is energy and light that impinges upon dark surfaces is far more likely to be absorbed and converted to kinetic energy, a.k.a. heat. Although I’m not sure, I bet the reason for only painting flat roofs white is because slanted roofs will reflect the light such that it will travel through far more of the earth’s atmosphere and therefore almost certainly be absorbed by the air, whereas a flat roof will reflect the light nearly vertically and thus the photons will be far more likely to escape our atmosphere back out to space. The solution is simple and cheap, yet elegant in its simplicity.

I feel that anybody who has completed a high school education in this country should be able to come up with the explanation that I just gave above, but the sad fact is that probably the majority of American’s could not give such an explanation, despite the fact that the overwhelming majority of Americans have completed high school. Science has been the hallmark of the advancement of all civilizations, why is “illiteracy” in science (and innumeracy) so acceptable in our society? Although left wing extremists will jump at the opportunity to make Rush look stupid, the general public won’t care. Although it is possible that Rush was being disingenuous and really did understand the simple ideas behind the proposal, but feigned ignorance for political reasons, I am more inclined to believe that he was being honest when he said he didn’t understand how it works.

We really need to look at how we teach in this country, and start experimenting with radical new approaches because this perfectly illustrates how inadequate current methods are. I realize changes in how science is taught have been made since Mr. Limbaugh attended school, but I am quite certain that most recent graduates would respond similarly.

Books: “Euler’s Gem The Polyhedron Formula and the Birth of Topology” by David S. Richeson

Euler's Gem book cover
This book is a beautifully illustrated gem! It examines Euler’s famous formula: V-E+F=2 which holds for all polyhedra or surfaces which are topologically equivalent to the sphere. The formula is an example of a topological invariant, something which can be computed for any surface, and thus allows one to categorize surfaces. The book also covers the famous classification theorem which categorizes all surfaces as either homeomorphic (topologically equivalent) to a sphere, n-handled torus, or sphere with n cross-caps (projective plane). Next it dives into knot theory and Seifert surfaces, before moving on to the interplay between topology and geometry, and ends by mentioning homology and how topology is done in higher dimensions.

Creating Printable PDF Flash Cards Using LaTeX

This post details how to make high quality, printable flash cards like I have available at my web site. I am assuming you are using Ubuntu Linux. I did this on Ubuntu 8.04 (Hardy Heron), but it might work on some previous and later versions as well.

First you want to install LaTeX, plus Andrew Budge’s flashcards package. Open a command terminal and type in the following command to install TeX and LaTeX. The flashcards package resides in the texlive-latex-extra Ubuntu package.

$ sudo apt-get install texlive texlive-latex-extra

I also recommend installing Kile which is a great program for editing TeX/LaTeX documents. You can do this with the following command. Depending on your system configuration, apt-get might require you to install several extra packages. The following is optional:

$ sudo apt-get install kile

At this point, if you try to compile a latex document that uses the flashcards package, you’ll get the following error:

! Package geometry Error: You must set \paperwidth properly.

To fix this, we need to create a small file called geometry.cfg, which tells the geometry packages which type of paper we will be using. Create the file using the following command:

$ sudo gedit /usr/share/texmf-texlive/tex/latex/geometry/geometry.cfg

Now copy and paste the following into gedit, save the file and exit from gedit.

%% This is file `geometry.cfg',
%% generated with the docstrip utility.
%% The original source files were:
%% geometry.dtx (with options: `config')
%% File: geometry.dtx Copyright (C) 1996-2002 Hideo Umeki
%% (
%% This package may be distributed under the terms of the LaTeX
%% Project Public License, as described in lppl.txt in the base
%% LaTeX distribution, either version 1.2 or (at your option)
%% any later version.

%% Uncomment and edit the line below to set default options.

%% End of file `geometry.cfg'.

Now, you should be able to compile a LaTeX document that uses the flashcards package without errors, but there will be some warnings. To fix the warnings, we need to change one line in flashcards.cls.

$ sudo gedit /usr/share/texmf-texlive/tex/latex/flashcards/flashcards.cls

The following diff command shows the change you need to make:

$ diff -ru flashcards.cls.bak flashcards.cls
--- flashcards.cls.bak 2009-01-26 17:15:27.000000000 -0700
+++ flashcards.cls 2009-01-26 19:43:57.000000000 -0700
@@ -83,7 +83,7 @@
- twosideshift=\oddevenshift,
+ twoside=true,

Now you should be able to compile a LaTeX document without any errors or warnings, excepting for any errors in your own markup of course.

Books: “Particle Physics A Very Short Introduction” by Frank Close

Particle Physics book cover
I found this book in the library the other day and found it to be a very good introduction to the basics of particle physics. I liked the fact that it explains the basics of the experimental side of particle physics as well as introducing the three families of leptons and quarks. Too often, popular science books explain the various subatomic particles with out giving you any idea of how we actually know of their existence. Because of this, I think disbelief tends to creep in. But Close does an excellent job of explaining the basics of how accelerators operate and also the basics of how detectors work. And he does all this in only 129 pages! Very short indeed, and highly recommended.

Algebraic Geometry: “Ideals, Varieties, and Algorithms” C++ Code

Ideals, Varieties, and Algorithms book cover
I did an REU (Research Experience for Undergraduates) this summer and we used the textbook “Ideals, Varieties, and Algorithms” (isbn 978-0-387-35650-1) by David Cox, John Little, and Donal O’Shea. As the title mentions, algorithms are an important tool in the study of varieties via their corresponding algebraic ideals. One of the main tools used in algebraic geometry is what is known as a Groebner basis, which is somewhat akin to a basis set in Linear Algebra. Anyway, I wrote some C++ code which implements a few of the algorithms in the book, but stops short of implementing Buchberger’s algorithm for computing a Groebner basis. The code should be useful as a starting point because it implements a Monomial class and a Polynomial class both with lots of useful methods thus eliminating the drudgery of implementing the book’s algorithms in C++.

The code can be found at: my web site as a gzipped tarball. Please let me know if you find it useful. I developed the code on an Ubuntu Linux machine, but it is generic enough that it should compile on any platform. You will need to read the README to understand the simple input, output format.