The Ride Home

Premonition

Reports were submitted, to-do lists composed, goodbyes bade, farewell meals cooked (and consumed), bread purchased, chocolates stuffed into impossible suitcase crevices, clandestine discussions carried out, sleep foregone, batteries recharged, to-do lists misplaced, buses boarded at ungodly hours- and I found myself on the same train as I had seventy six days ago. Admittedly, I was too preoccupied with the Deathly Hallows to soak in the sights this time, but Frankfurt airport brought me back to the muggle world with a resounding thud that must have sounded similar to an egg cracked too hard on the edge of a pan.

Why, you ask?

Yes, the airport was mind bogglingly monstrous (more easily navigated by segways, I would think) and bustling with people scampering in all directions except towards where the signs point to. What really made me put down the book, though, was my boarding pass, and the smattering of forty twos on it- the gate I was supposed to board from, the seat I was alloted, and the number on a baggage identification tag.

42.

Forty two.

Something was up- and I was determined to keep my eyes open for something unusual.

Revelation

About two hours into the leg-space-less flight, it struck. What struck is irrelevant- Something that hadn't made sense in a long time- happened (and made less sense than ever), and I realized that had the conspicuous forty twos not preceded the incident, I might have missed it completely.

The rest of the flight was spent in trying to make sense of what had happened, and in trying to find a way to put it up here without being explicit.

Homecoming

The roads seemed tiny, the traffic crazy, the smoke stinging, the weather damp and foul, the time lead disconcerting- but these quibbles disappeared in the elation of reaching my destination- home.

And so it ended.

The Right Pinky of God

Digression: An excerpt from Neal Stephenson's "In the Beginning was the Command Line" :

In his book The Life of the Cosmos, which everyone should read, Lee Smolin gives the best description I've ever read of how our universe emerged from an uncannily precise balancing of different fundamental constants. The mass of the proton, the strength of gravity, the range of the weak nuclear force, and a few dozen other fundamental constants completely determine what sort of universe will emerge from a Big Bang. If these values had been even slightly different, the universe would have been a vast ocean of tepid gas or a hot knot of plasma or some other basically uninteresting thing--a dud, in other words. The only way to get a universe that's not a dud--that has stars, heavy elements, planets, and life--is to get the basic numbers just right. If there were some machine, somewhere, that could spit out universes with randomly chosen values for their fundamental constants, then for every universe like ours it would produce 10^229 duds.

Though I haven't sat down and run the numbers on it, to me this seems comparable to the probability of making a Unix computer do something useful by logging into a tty and typing in command lines when you have forgotten all of the little options and keywords. Every time your right pinky slams that ENTER key, you are making another try. In some cases the operating system does nothing. In other cases it wipes out all of your files. In most cases it just gives you an error message. In other words, you get many duds. But sometimes, if you have it all just right, the computer grinds away for a while and then produces something like emacs. It actually generates complexity, which is Smolin's criterion for interestingness.

Not only that, but it's beginning to look as if, once you get below a certain size--way below the level of quarks, down into the realm of string theory--the universe can't be described very well by physics as it has been practiced since the days of Newton. If you look at a small enough scale, you see processes that look almost computational in nature.

I think that the message is very clear here: somewhere outside of and beyond our universe is an operating system, coded up over incalculable spans of time by some kind of hacker-demiurge. The cosmic operating system uses a command-line interface. It runs on something like a teletype, with lots of noise and heat; punched-out bits flutter down into its hopper like drifting stars. The demiurge sits at his teletype, pounding out one command line after another, specifying the values of fundamental constants of physics:

universe -G 6.672e-11 -e 1.602e-19 -h 6.626e-34 -protonmass 1.673e-27....

and when he's finished typing out the command line, his right pinky hesitates above the ENTER key for an aeon or two, wondering what's going to happen; then down it comes--and the WHACK you hear is another Big Bang.

Now THAT is a cool operating system, and if such a thing were actually made available on the Internet (for free, of course) every hacker in the world would download it right away and then stay up all night long messing with it, spitting out universes right and left. Most of them would be pretty dull universes but some of them would be simply amazing. Because what those hackers would be aiming for would be much more ambitious than a universe that had a few stars and galaxies in it. Any run-of-the-mill hacker would be able to do that. No, the way to gain a towering reputation on the Internet would be to get so good at tweaking your command line that your universes would spontaneously develop life. And once the way to do that became common knowledge, those hackers would move on, trying to make their universes develop the right kind of life, trying to find the one change in the Nth decimal place of some physical constant that would give us an Earth in which, say, Hitler had been accepted into art school after all, and had ended up his days as a street artist with cranky political opinions.

It's all cracked up to be- and worth a read. In one giant text file, Neal Stephenson goes from the war of the OS's to Milwaukee drills, the Egyptian taxi culture, arcane abbreviations, the Morlocks and the Eloi (Read Wells!), the virtues of indigence, and contemplates taking a menu driven GUI enabled car out for a ride. Allusions to media steepage, metaphor shear, geek fatigue, the importance of wanton fecklessness, the Disneyland experience, and the wisdom of maintaining bug reports all tie in to explain why people abdicate their will to learn, and why everyone is willing to be taken for a ride.

The art of mental math is fast disappearing. Today, the sight of a double-Fourier-integral sends shivers up the spines of many, and the unfortunate few who must live with it scamper to the nearest terminal loaded with Mathematica/Matlab. Master computers like Fermi, Bethe and the no-adjective-suffices Feynman-

Never mind.

At this point of the composition, I googled to find an excerpt from 'Surely You're Joking, Mr. Feynman', one where he describes how he computed e to the {something} in his head faster than his mates could on paper, and one from 'Genius', where Gleick details Feynman's unconventional methods of summing sequences.

Neither of these excerpts turned up. Instead, I spent two and a half hours re-reading (now) familiar trivia about him, which was the time I had allowed myself for this post- and must now move on to other things. I no longer remember what I intended to write, or why I had planned to mention Bessel functions.

{Shrug} I give up. (And Feynman is God. No, really, Murray Gell-Mann said something of the sort.)

Looking for the light switch

The roller I was supposed to work on has been dispensed with, for the most part, and owing to an over-abundance of free time, I have turned my attention towards dilettantish attempts at resolving fundamental inconsistencies in fluid mechanics- or at least, to seek a compromise as only an inexperienced, intuition deprived tyro can.

This post is not about these inconsistencies.

Instead, I intend to remember what two weeks of intense brainstorming and (slight) sleep deprivation (read: work) felt like, and will attempt a vivid, voluble description/recollection of this period of time here.

Working on an unsolved problem that is so deceptively simple in its statement that it conjures an image of a jigsaw puzzle with a pivotal element missing seemed like an award in itself- but as I soon discovered, things change when you stoop down to the equations and get your hands dirty. (If you must know, it's #3 here.)
To put it simply, it feels like groping in the dark, looking for a light switch, and bumping into walls, table edges and bed posts every now and then. You never quite know if what you're doing is leading somewhere, or whether you will be starting over in a short while. Intuition fails miserably, and you realize the jigsaw puzzle is missing its defining piece- I've lost count of the number of times I recalled Thomas Kuhn's words- and the number of times I've vowed to read through his magnum opus again.

Collaboration, I realized, is good. Five heads are better than one, as long as they're all thinking along different lines. It also becomes evident why much of today's science rests heavily on collaboration; deplorable one-upmanship and egoistic concerns lose all meaning in the face of the problem at hand.
I really couldn't care less about who solves the problem- that the problem is resolved will imply a small, but firm step ahead in our understanding of nature- an understanding that I will share- no matter who stumbles upon the missing piece. (It is with this reassurance that I go back to my banal, platitudinous life at college.)

This post will, in all likelihood, appear to have made a mountain of a proverbial molehill once the issue is resolved, (quite obviously, not by me!) but with Kuhn's words ringing in my ears, that's a chance I'm willing to take. It is unlikely, perhaps impossible, that I will look any sillier than I already do.

So what is it like figuring out the Galilean invariance of Momentum Transport Equations?
Two parts enervating, two parts humbling, and one part inspiring, but mostly scary. If this is what fundamental research feels like, though, sign me up any day. I'm game.

You notice the strangest things about fluid motion if you're paying attention to nature. This, for instance:



No prize for guessing what's happening (or why), of course, but I would sure like to simulate this on my box once I get back to college. As of now, I'm trying to compute the frequency of oscillation based purely on order of magnitudes of the flow parameters. (The Rayleigh, Reynolds, and Strouhal numbers, to be precise. Perhaps the Froude number as well- I don't know yet.)

And then this, which doesn't look like much here, but was mesmerizing when I saw it happen:



Reflected and incident waves interfering to create slinky like seemingly transverse waves. A deception, of course- I know there's a considerable longitudinal component to surface waves in water, and I think there's a considerable longitudinal component to the resultant here, as well. This was, by the way, at the lake here.

Weird, eh?

Levity (and persiflage) on demand

"Mr. Chik-mal..."
"Mr. C"
"Mr. Ka..."

By the gods, I'm yet to meet someone who can pronounce my name right. I don't blame them though, I get it wrong myself half the time.

Like the penurious gentleman who dons tattered apparel because he couldn't care less about what people who don't know him think about his attire, and because people who know him couldn't care less about his attire, I'm stuck with a name that I can make as much sense of as my hosts here. People who just don't get it don't care anyway, and people who do get it think its a private joke.

I'm not sure what requirement my name serves, save for sending both kinds of people into fits of laughter. Including me.

Private joke, indeed.

On mind-numbing inconsistencies in momentum transfer, and Galilean invariance

1. Imagine a layer of air moving across a water surface. If we observe the situation sufficiently "downstream", the water surface is moving too. It follows that the velocity of the air and the water at the interface is the same. Air molecules move into the interface with a certain momentum, but emerge, several collisions later, with the velocity of the water at the surface- its the same with the water- so both move at the same velocity.
Now, let's look at the momentum(s). The velocities are the same, but the momentum of the air and the water at the interface are not- Water convects about a thousand times more momentum than the air. (This is the ratio of their densities.) And yet, the net momentum transfer through diffusion is from the air to the water- the air set the water in motion, remember?

2. A fluid flows over a flat plate- and you get to see a boundary layer form. A nice velocity profile develops, and the net result is the transfer of momentum from the water to the plate. This vague expression manifests itself in the gradient of the velocity component perpendicular to the plate. In particular, towards the edge of the boundary layer, the gradient of the perpendicular component of the velocity is greater than zero. (Think continuity, and the fact that the parallel component of the velocity at the edge of the boundary layer decreases along the length of the plate as the boundary layer grows.)
Now drag the plate instead. At the edge of the boundary layer, the parallel component increases along the length as the boundary layer grows. The result, therefore, is that the gradient of the perpendicular component (along the perpendicular direction) decreases.
The reason for the emphasis? The aforementioned situations are, at the face of it, the same, save for a change in frame of reference.
And yet, the gradient of the perpendicular component, which is unaffected by the coordinate transformation, is simultaneously positive and negative!

3. The Navier Stokes Equations are not Galilean invariant. Beats me, but its true. There's a hint of broken symmetry here- and a flaw that is as elusive as it is enigmatic.

I'm being peppered with paradoxes all day long- I'm not surprised I can't get any real work done nowadays.

EDIT: (1) is now resolved. There is no inconsistency. Both thumbs up to Mr. Sambashivam and his penetrating insight into the issue. On the off chance that the garbled, obfuscating, voluble description of the apparent inconsistency made sense to you, and that you're curious to know what the resolution is, comment, and ye shall find the elucidation you seek.

On notice boards

The local university has an Institute of Fluid Mechanics, and an Institute of Computational Engineering. (I do not work at either of these places.) Not surprisingly, these two buildings are neighbours- one of them frames problems for the other to solve.

What really tickles me, though, is what the computational engineers have on their walls. At the entrance to the local supercomputer room:















(If you knew German, you'd be cracking up about now.)

Their notice boards are a crack!

(Humorous Sysadmins?)


I know- its blurred- but I've read the original, and I have no clue either. Blurting "Neumann!" a few times didn't work.

Here's how you write "Hello World" in every programming language known to man:

I don't know what this is about, but hey, Homer-



Vollwaschmittel translates roughly to "whole washing powder"- but whether its an actual product or an obscure, elaborate practical joke is anybody's guess.


UPDATE: Their sense of humour goes beyond notice boards- gaze at the door to the washroom:



And finally, a painting that is simultaneously anachronistic and incongruent. If it serves any purpose in the computational engineering department other than to puzzle the viewer, I am unaware of it.

The dilemma

How does one design an experiment?

'll be darned if I know.

{Shrug}

Food Update V

Noodles. You can't mess this up. Even I can't.



As for the following exhibit, I'm not sure if it was intended to be pulav, rice bhat or khichdi. It tasted like none/all of the above and still managed to taste good.

I got it right the second time, though. I think the powers that be willed for it to be khichdi. I would have settled for less.


I know- it looks nice.