Rammed Earth Building (like the Great Wall)

Rammed Earth or Stabilized Earth building technique is basically building solid earth walls by compressing/compacting a mixture of earth, sand and may be some cement in place, using "forming" devices like a wooden shell. Once the earth is dry, the forming device is removed, and the next section of the wall is rammed in.

Benefits:

Thermal Flywheel Effect - the earth stores heat during the day and releases it at night
Indoor air quality
Longevity, durability, low-maintenance
Fire and Insect resistance
Environmentally Friendly
Intangibles - great feeling, quietness of solid earth walls...

Recently, MIT researchers experimented with a building technique used more than 2000 years ago in the Great Wall of China. They used local Boston blue clay, mixed it with two parts sand and gravel, packed the mixture by hand and a pneumatic compactor into a wooden shell that was removed once each section was complete and dry. The wall which was started in September 2005 is apparently doing just fine 2 months later.

This technique will not be suitable for applications where strength is important. However, a neat application, for example, would be for building the acoustic proofing walls by the side of highways. Apart from looking more aesthetic, thanks to the wall essentially being made of the same material as the surrounding land, it'd be environmentally friendly too, as much of the material used uses little processing.

eh, well, freakonomics :(

Don't get me wrong: I love this freakonomics thing. I just finished the book (in audio form), and have thoroughly enjoyed it. But what bothers me is that it's become so "hip". Somehow all this hype lessens the legitimacy of the thing. Nevertheless, the basic philosophy of the book is well in line with the way I think, and that's great. If anything, this book is going to make me even more skeptical of conventional wisdom.

Also, the book is a mild wakeup call for me during a time I have been growing more and more gullible to the "experts". And it's a breath of fresh air to see how economics is much more than mere numbers - it's music to the ears of someone who's been professing a fascination for economics oflate, but has always been wary of the mathematics involved!

Clair Patterson: The Man Who Found Out Earth's Age

Clair Patterson invented a method of isolating/estimating minute quantities of lead isotopes present in rocks, and this led him to determine the age of the earth (something like 4.6 billion years) for the first time in human history.

He later went on to show that human industrial activity was causing the lead levels in the atmosphere (and so in the rocks and antarctic ice) to increase to dangerous levels. He fought a lone battle against the Ethyl corporation, the manufacturers of tetra-ethyl lead, the anti-knock additive in gasoline. It was largely becasue of his effects that the "Clean Air" bill was passed and TEL was banned in the United States.

(First learnt from Bill Bryson's "A Short History of Nearly Everything")

Central America Deforestation

In 1986 Tom Sever, NASA's only archaeologist, acquired a satellite image of northern Guatemala to examine it for archaeological sites. As soon as he glanced at the image, Sever "was stunned that he could see the political border between Guatemala and Mexico, because of the deforestation in Mexico,".



Above: The razor-sharp border between Mexico and Guatemala, as seen in this 1988 Landsat image, shows the impact of rural settlements on the rainforest.


The image was so powerful, it was published in National Geographic magazine, and became a catalyst for the president and congress of Guatemala to set up what they call the Mayan Biosphere Reserve—Guatemala's largest protected area.

Bigger picture:


Credit: Science@NASA

Douglas Adams' Babel Fish

Adams at his best!

"The Babel fish, is small, yellow, and leechlike, and probably the oddest thing in the universe. It feeds on brainwave energy received not from its own carrier but from those around it.It absorbs all unconscious mental frequencies from this brainwave energy to nourish itself with. It then excretes into the mind of its carrier a telepathic matrix formed by combining the conscious thought frequencies with nerve signals picked up from the speech centers of the brain which has supplied them. The practical upshot of all this is that if you stick a Babel fish in your ear you can instantly understand anything said to you in any form of language. The speech patterns you actually hear decode the brainwave matrix which has been fed into your mind by your Babel fish. Now it is such a bizarrely improbable coincidence that anything that mindbogglingly useful could have evolved purely by chance that some thinkers have chosen to see it as a final and clinching proof of the nonexistence of God. The argument goes something like this: "I refuse to prove that I exist," says God, "for proof denies faith, and without faith I am nothing." "But," says man, "the Babel fish is a dead giveaway, isn´t it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don´t. QED." "Oh dear," says God, "I hadn´t thought of that," and promptly vanishes in a puff of logic. "Oh, that was easy," says man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing. Most leading theologians claim that this argument is a load of dingo´s kidneys, but that didn´t stop Oolon Colluphid making a small fortune when he used it as the central theme of his best-selling book, Well That about Wraps It Up for God. Meanwhile, the poor Babel fish, by effectively removing all barriers to communication between different races and cultures, has caused more and bloodier wars than anything else in the history of creation."

What's heavier: a kg of lead or a kg of cotton?

A few years ago I was idly musing some basic physics when this occured to me. I was quite thrilled to independently hit upon a cute clever physics puzzle :) So here goes it:

What's heavier: a kg of lead or a kg of cotton?

Trick question, huh? No, actually. Just a clever one.

Now, some implicit assumptions have to be disclosed. We are talking about the weight of, say a lead ball vs. the weigth of say, a bundle of cotton, on the surface of the earth.

The answer is that the cotton is heavier!

The reason is the dramatically different buoyancy of these two objects in air. In simple terms, air pushes "up" the lighter cotton more than the heavier lead ball. (Because both are fully immersed in the Earth's atmosphere, they each displace an amount of air equal to their respective volumes. The buoyant force is equal to the weight of the displaced air. So, cotton experiences more buoyant force.) When we weigh the cotton bundle to be a kilogram, we need to adjust for the buoyant force, which makes it seem lighter than it actually is. This adjustment applies to lead also, but to much smaller extent. So, the cotton bundle will turn out to be a wee bit more than 1kg in actual terms (when weighed in vaccum) than the lead ball.

Einstein

(From a Science@NASA article by Dr. Tony Phillips)

Einstein didn't resist being told what to do, not so much, but he hated being told what was true.

In 1905, Einstein had just received his Ph.D. He wasn't beholden to a thesis advisor or any other authority figure." His mind was free to roam accordingly.

In Einstein's day, if you tried to say that light was made of particles, you found yourself disagreeing with physicist James Clerk Maxwell. Nobody wanted to do that. Maxwell's equations were enormously successful, unifying the physics of electricity, magnetism and optics. Maxwell had proved beyond any doubt that light was an electromagnetic wave. Maxwell was an Authority Figure.

... (It was because Einstein didn't care for authority, that he boldly got to solutions for problems like photo electric effect, before more experirnced Physicists like Max Planck did.)

In retrospect, Maxwell was right. Light is a wave. But Einstein was right, too. Light is a particle. This bizarre duality baffles Physics 101 students today just as it baffled Einstein in 1905. How can light be both? Einstein had no idea.

That didn't slow him down. Disdaining caution, Einstein adopted the intuitive leap as a basic tool. "I believe in intuition and inspiration," he wrote in 1931. "At times I feel certain I am right while not knowing the reason."

...
"I have no special talents," Einstein claimed, "I am only passionately curious." And again: "The contrast between the popular assessment of my powers ... and the reality is simply grotesque." Einstein credited his discoveries to imagination and pesky questioning more so than orthodox intelligence.

Einstein: "The fairest thing we can experience is the mysterious," he said. "It is the fundamental emotion that stands at the cradle of true art and true science."

Why?

"Why?" is perhaps the most meaningless question in the universe.

It's a short-coming of the human mind, that it needs a reason for everything. 'Cause and Effect' is the single most important tenet of human thinking. Yet, it could be utterly irrelevant, or worse, counter-productive, when applied to the fundamentals of the universe itself. The ToE or God (or whatever is your favorite omnipotent, omniscient entity - OOE, we'll call it) doesn't need a reason to do things (or not do things). We humans, somehow, always do. Not only do we do, but it's the only way we can comprehend.

"Why did the OOE make us this way?", is a good question, indeed!

Badri Srirangam's Random Walk Thru Life

What the heck? I'll allow myself some vanity, and publish my opinions for all to read (or ignore).