Thursday, August 27, 2009

Robert Heinlein and Specialization

Having spent my life learning more and more about less and less, and being envious of people who know more and more and more of less and less and less, this Robert Heinlein quote offers refreshing perspective.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
"Stranger in a Strange Land" by Heinlein is one my all-time favorite SciFi novels. This particular quote is not from that book, however.

Saturday, August 22, 2009

Returning to India

One of my friends from IIT Bombay, Kashyap Deorah, who moved back to India a couple of years ago has written a couple of absolutely fascinating essays on the subject. Speaking through metaphors, it dwells one level below the completely abstract, and one level above the completely mundane.

Here is are links to the first, and the second essays.

Wednesday, August 19, 2009

OpenOffice Impress + OOoLaTeX = Presentations on Steroids!

Okay, I got carried away with the title, but occasionally things happen, which forever change the way you do many regular tasks. And some irrational exuberance is warranted.

I've successfully weaned myself away from non-free software, over the last decade. So no, I don't use MS Windows, MS Office, Mathematica, SigmaPlot, Material Studio, Fluent, Matlab etc. anymore. Instead, I use Linux, LaTeX+OpenOffice, Maxima, gnuplot+xmgrace, LAMMPS, OpenFOAM, Octave etc. In most cases, my choices are superior, and in some cases, despite their flaws, they are adequate for the types of things I do, and the kind of person I am [I like command lines, can compile things from source, don't mind hacking around a little bit if short term inconvenience ensures long-term peace]. So this entry is heavily biased by my computing habits and temperament.

I've never really liked how equations turn up on MS Office or OpenOffice (without paying for MathType - I'm cheap I told you!). Presentations using a LaTeX class like beamer or seminar, is an option, but most of my presentations unlike my documents don't have too much cross-referencing, structure, etc. What I really miss is professional layout of mathematical formulae. Recently, I started using this plugin called OOOLaTeX. Installing it on OOo 3.0 was a breeze. This is on a Linux machine, on which LaTeX and ghostscript were already installed.

1. Just go to Tools -> Extension Manager -> Get More Extensions here.
2. Search for OOOLaTeX
3. "Get It", which allows to download an "oxt" file.
4. Install it, by choosing "Add" in the extension manager.
5. Download "Bakoma" fonts (which look like the Computer Modern fonts in standard LaTeX documents) and push them into your fonts directory.

You're set. The following is my own document. The one above, obviously, is not mine. I got that from the official Screenshots (the writer is French).

Saturday, August 15, 2009

I love IIT Bombay!

Didn't notice this before, but am glad my alma mater is taking a stand!

I have nothing personally against Microsoft, and I am not against commercial software, although I don't use much of it. But I am most certainly for open formats like PDF, ODF, SVG etc.

Wednesday, August 12, 2009

Does the human skin sense temperature?

The answer is no, if you are in a hurry. But if you have time, let me pose a puzzle:

"Your body temperature is about 37C or 98F depending on which side of the Atlantic you are. If you are like most people it "feels" quite uncomfortable when the temperature outside is 37C. When asked most people say they like 20-27C (or 65-80F). "


The basic point is that our body is constantly producing heat. In fact, most of the food we eat is eventually converted to heat. This should explain why the average daily intake of an adult is approximately 2500 calories, while only about 300 of those are consumed by jogging for 30 minutes.

For heat to flow, it needs a temperature difference. Thus, the 10-12 celcius difference that a 25 celcius environment provides, enables us to efficiently dissipate the heat we constantly generate. This leads us to the answer.

Our skin senses heat flow (flux), not temperature.

There are several manifestations which illustrate this point:
  • When you sleep, you feel colder because your body processes have slowed down, producing less heat.
  • When it is hot your body sweats. Sweat vaporizes, and in doing so takes away a lot of heat from your body (aka latent heat of vaporization).
  • When it is windy you feel colder because heat is being convected away from your body faster (the wind chill effect).
Notice, how the outside temperature is only one of the factors which governs how "hot" or "cold" we feel. The mere fact that other things, such as level of activity, humidity, convection, perspiration affect that feeling suggests that we don't sense outside temperature.

Saturday, August 8, 2009

Feynman Lectures

I found a this link via Simoleon Sense. It is really a fabulous resource, and I highly recommend it, even if your interest in physics is only marginal.

From the blog:
Apparently, Bill Gates has purchased the rights (to many of the Feynman lectures) and posted them for free on his Microsoft Research Labs “Project Tuva”. I can’t recommend these enough, Feynman had the ability of teaching science in a simple, insightful, and eloquent manner.

Often all it taken to enliven a dull subject is a spectacular teacher, and few can doubt Feynman's charisma. What Warren Buffet is to investing, Feynman is to general physics. They serve their specialties with a hearty dose of common-sense and humor.

The only problem with these lectures is that it requires SilverLight!

Sunday, August 2, 2009

Spicy Stuff

One of the blogs I follow, brought my attention to this article, which is an interesting take on the spice: asafoetida or hing. My dad loves the spice, and as kid, I hated it.

With age comes maturity, and a tempering of strong emotions, and these days I don't mind it as much.

Interesting tidbits from the article, which I definitely did not know were:

1. its source:

the farmer digs away the soil around the plant and makes an incision in the top of the thick carrot-like root, which then exudes, for about three months, as much as a kilogram of the milky resin. It hardens on exposure to air and gradually turns brown.
2. that asafoetida means "stinking resin" (very apt!). Sulphides are the culprit, as usual. If you recall, a relative - hydrogen sulphide - is partly responsible for smelly farts, and rotten eggs. By the way, it is also flammable, so don't do it near a campfire or a smoker.
3. This is interesting, even ironical, since,

Not unnaturally, the resin has been thought to have very many medicinal uses. Its most common use is to treat indigestion and flatulence. Even today, a bit of it is pasted on the stomach (belly button) of an infant, with the idea that it relieves “locked” gas and aids in digestion.
Apparently this is one of the reasons why it is usually added to dishes containing lentils and beans.
They contain molecules that disturb the enzyme carbonic anlydrase and thus produce gas. And asafoetida helps in relieving this effect – or so the theory goes.
4. Check out the comments on Guru's blog, if you read the article. I really like the keen observation made in the first comment.