One of my favorite science fiction authors, Arthur C. Clarke passed away yesterday. Back in my school days, his book 2001: A Space Odyssey (the book, not the movie) was probably the first book which had a major impact on me, challenging my preconceived notions about the universe, god, religion etc. It also got me hooked on science fiction books: the smart ones (Clarke, Asimov, Niven etc.), not the Star Wars/Star Trek types. I believe good science fiction is probably the only genre which lets you 'stretch your imagination' beyond what you thought was possible.
I leave you with a video he broadcasted on his 90th birthday, just 3 months ago, in which he talks about the past, present and especially the future. Great stuff.
Showing posts with label science. Show all posts
Showing posts with label science. Show all posts
Wednesday, March 19, 2008
Sunday, November 18, 2007
On Evolution
I often hear people asking the question: Do you believe in Evolution? Well, for starters, Evolution happens. It is a fact, not something you believe or not believe in.
Evolution is one of the topics not taught in schools in India. As a result, many people I speak to have an incorrect notion of evolution. Back in high school, I remember learning about botany and zoology and the difference between classes of animal kingdom, but nothing about how this variation came about. We learn the answer to the 'What' question, totally sidetracking the more fundamental 'How' and 'Why' questions.
In reality the process of natural selection (via which evolution occurs) is a simple and fascinating concept. Unfortunately most of the literature on the net, like this Wikipedia article, is rife with scientific terminology, making it too intimidating for a layman to understand.
Here is an amazing clip from Carl Sagan's Cosmos series where he explains natural and artificial selection using the Heikegani crabs as an example in a very clear and lucid manner. Check it out...
Carl Sagan is one of my favorite authors and the entire Cosmos series is worth watching. Or if you prefer the book, it is equally good. Definitely something worth checking out.
Evolution is one of the topics not taught in schools in India. As a result, many people I speak to have an incorrect notion of evolution. Back in high school, I remember learning about botany and zoology and the difference between classes of animal kingdom, but nothing about how this variation came about. We learn the answer to the 'What' question, totally sidetracking the more fundamental 'How' and 'Why' questions.
In reality the process of natural selection (via which evolution occurs) is a simple and fascinating concept. Unfortunately most of the literature on the net, like this Wikipedia article, is rife with scientific terminology, making it too intimidating for a layman to understand.
Here is an amazing clip from Carl Sagan's Cosmos series where he explains natural and artificial selection using the Heikegani crabs as an example in a very clear and lucid manner. Check it out...
Carl Sagan is one of my favorite authors and the entire Cosmos series is worth watching. Or if you prefer the book, it is equally good. Definitely something worth checking out.
Sunday, February 18, 2007
Us
I like this image of the earth taken by one of the Voyager spacecrafts. From Carl Sagan's book Pale Blue Dot:
Look again at that dot. That's here. That's home. That's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar", every "supreme leader", every saint and sinner in the history of our species lived there — on a mote of dust suspended in a sunbeam.Really puts things in a perspective, doesn't it?
P.S. "thousands of confident religions"?? Nicely put :)
Friday, January 19, 2007
The shortest (flight) path problem
While on the unbelievably long India flight, I was thinking about flight paths that planes take when they travel around the world. I stuck upon this easy way of finding the shortest path between any 2 cities in the world.
Most people believe that the shortest distance between any 2 cities in the world is via the path obtained by drawing a straight line between them on a map. Take for instance Seattle and Paris. Both lie roughly on the 48th latitude. Seattle around 120 E longitude, while Paris roughly near 0 i.e. Greenwich Meridian. So the fastest way to go from Seattle to Paris is to simply go east along the 48th latitude till we hit Paris. Right? Wrong..... The truth is, that unlike a map, the earth is not flat. It is a sphere (It is actually a geoid, but for the sake of argument here we will assume it is a nice symmetrical sphere).
So what is the shortest distance between any two points on the surface of a sphere? Here is a simple way of finding it out:
Draw a circle, centered at the center of the earth and passing through these two cities. The smaller arc of the circle joining the two points is the required shortest path. The 3d symmetry of a sphere dictates that this should be the right answer and I am not gonna take the pains of proving it :). It is true at the poles and true at the equator and you could possibly prove by induction that it is true every point in between.
Thus for any 2 cities in the Northern Hemisphere, the shortest flight path curves northwards and vice versa for cities in the Southern Hemisphere. For cities on symmetrically opposite longitudes, e.g. Seattle (~120 W) and Dubai (~60 E), the shortest path passes through one of the poles (in this case, the North Pole).
Most people believe that the shortest distance between any 2 cities in the world is via the path obtained by drawing a straight line between them on a map. Take for instance Seattle and Paris. Both lie roughly on the 48th latitude. Seattle around 120 E longitude, while Paris roughly near 0 i.e. Greenwich Meridian. So the fastest way to go from Seattle to Paris is to simply go east along the 48th latitude till we hit Paris. Right? Wrong..... The truth is, that unlike a map, the earth is not flat. It is a sphere (It is actually a geoid, but for the sake of argument here we will assume it is a nice symmetrical sphere).
So what is the shortest distance between any two points on the surface of a sphere? Here is a simple way of finding it out:
Draw a circle, centered at the center of the earth and passing through these two cities. The smaller arc of the circle joining the two points is the required shortest path. The 3d symmetry of a sphere dictates that this should be the right answer and I am not gonna take the pains of proving it :). It is true at the poles and true at the equator and you could possibly prove by induction that it is true every point in between.
Thus for any 2 cities in the Northern Hemisphere, the shortest flight path curves northwards and vice versa for cities in the Southern Hemisphere. For cities on symmetrically opposite longitudes, e.g. Seattle (~120 W) and Dubai (~60 E), the shortest path passes through one of the poles (in this case, the North Pole).
Sunday, October 22, 2006
The book of life
In the beginning were the replicators. Their sole purpose of existence was to make copies of themselves. Survival was tough. The environment, the primordial soup was harsh.
As time went by, the replicators became more and more efficient. Some of them roped in the elements and developed effective ways of prolonged survival. Some others found strength in unity and formed extensive colonies of similar replicators. The colonies evolved into complex survival machines. The replicators controlled everything that went on in these survival machines. Survival was easy for the ones better designed, others slowly died out.
The quest for perfection continued. The replicators became sufficiently ingenious to build the most complex machine ever built. They built the "Brain". Deeply embedded in the survival machines, the brain created a process called "thought". Thought was a complex process, which lead to formation of other forms of replicators, such as the memes. They made the machines ignore their real masters, the replicators and made them worship the new ones, the memes and their derivatives. Chaos reigned. The machines misconstrued it as Order......
As time went by, the replicators became more and more efficient. Some of them roped in the elements and developed effective ways of prolonged survival. Some others found strength in unity and formed extensive colonies of similar replicators. The colonies evolved into complex survival machines. The replicators controlled everything that went on in these survival machines. Survival was easy for the ones better designed, others slowly died out.
The quest for perfection continued. The replicators became sufficiently ingenious to build the most complex machine ever built. They built the "Brain". Deeply embedded in the survival machines, the brain created a process called "thought". Thought was a complex process, which lead to formation of other forms of replicators, such as the memes. They made the machines ignore their real masters, the replicators and made them worship the new ones, the memes and their derivatives. Chaos reigned. The machines misconstrued it as Order......
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