Viswanathan K's Thoughts

One of Isaac Asimov’s tales is titled The Final Question . Well into the future, the very hi-tech inhabitants of the future are worried. By the second law of thermodynamics! Or rather, the implied consequence of that law.   Without getting into the details of what the law is, let’s focus on the consequence that is scary. The law implies that everything in the universe will eventually cool down and decay. In that setup, no free energy will exist to drive any further processes. It is called the “heat death of the universe”.   Or as TS Eliot poetically put it: “This is how the world ends. Not with a bang, but with a whimper.”   So these hi-tech inhabitants ask their cosmic supercomputer: How can the second law of thermodynamics be overturned?   The supercomputer starts working on the question. Eventually, long after all life has ended, the stars have died out, and as nothing new emerges in the universe, and the universe is on the cusp of the gloomy end...

Given the future we are headed towards with its AI, self-driven cars and drones (and who knows what other forms of “smart” software”?), governments world over worry about security implications. And yes, governments can look outside the bureaucratic box, as seen in Bruce Schneier’s description of one such US initiative a decade back: “The Department of Homeland Security hired a bunch of science fiction writers to come in for a day and think of ways terrorists could attack America. If our inability to prevent 9/11 marked a failure of imagination, as some said at the time, then who better than science fiction writers to inject a little imagination into counterterrorism planning?” Schneier though sees a problem with consulting sci-fi writers: “More imagination leads to more movie-plot threats -- which contributes to overall fear and overestimation of the risks. And that doesn't help keep us safe at all.” Rather, he prefers this model: “Science fiction writers are c...

Ever since Newton, one would think that the position of any planet can be predicted for all time. Except that one would be wrong! Just having 3 objects in the scenario makes calculations very tough! That’s the (in)famous “three-body problem”. (And in case you wondered, yes, the first three-body problem people tried to solve involved the sun, earth and moon). You might be thinking if it’s so tough for humans, why not just throw a computer at the problem? Aha, but the point is in this line from Wikipedia : “There is no general closed form solution for every condition.” Put simply, the problem is that, for almost all starting positions, there is no equation into which you plug in the masses, coordinates and velocities at time zero and then find where they’ll be at all instants in the future. Sure, you can calculate positions instant by instant , but that still means we don’t the answer for all time. For example, consider the more general form the problem, the n-body problem (wh...