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Requiescat In Pace

April 18, 2008

This has been a somewhat sad week for science, physics in particular. John Archibald Wheeler passed away on April 13, and a few days later on April 16, Edward Lorenz died.

I first came across Wheeler’s name as a first year undergraduate student while reading James Gleick’s biography of Richard Feynman, entitled Genius. All I remembered about him from that book (and what most non-physicists might care to remember about him) was that a) he coined the term “black hole” and b) he was Richard Feynman’s Ph.D. advisor.

A wonderful personal tribute to the man can be found here. On that blog, someone kindly posted a link to a series of video interviews about his life and times. Its a wonderful repository of information for anyone curious or just fascinated by the golden age of physics. Other interviews include those of Dyson, Gell-Mann, and Teller.

Edward Lorenz was a name I encountered less than a week ago ! A colleague in Lab, drew my attention to a book, “Nonlinear systems and Chaos” by Steven Strogtaz. I have only managed to go through the first two chapters of the book, in what is my first serious attempt to understand nonlinearity and chaos. Although I had heard of the butterfly effect, I hadn’t connected it to the name Edward Lorenz. During the course of this past week, this oversight has indeed been emended ; by virtue of the book, as well as the sad demise of Edward Lorenz.

There are plenty of videos out there that illustrate nonlinear phenomena, but for me personally, the following was most pedagogically efficacious (and brief):

Hap(pi) Birthday !

March 14, 2008

Today, March 14, (3/14) happens to be π day, as well as Albert Einstein’s birthday. Here’s a nice little article on π from the BBC Science section.

Shock and Ohh !

February 26, 2008

While browsing through my copy of Electric Circuits by Nilsson and Riedel, I came across a table which listed the physiological reactions to current levels in the human body:

REACTION                     CURRENT

Barely perceptible             3-5 mA

Extreme pain                     35-50 mA

Muscle paralysis                 50-70 mA

Heart Stoppage                 500 mA

…and then the quote, “The numbers in this table are approximate; they are obtained from an analysis of accidents because, obviously, it is not ethical to perform electrical experiments on people”.