11.01.2010

Perspective.

Perspective - What engineering and a lot of curiosity can teach you.

(Dedicated to the ultra strong coffee that just made my morning today. You'd better have one too, in case this gets too much on your nerves and you end up like this.)

I'm gonna take the example of the modern day machine - the aircraft. A teeny weeny bit of its HUGE system. A tiny bit of the whole stuff that happens during operation, the take-off. Even more particularly, one operation - the engines pushing you forward. I might not be exactly technically correct to every detail, I wish I was, but I'm kinda not far off. Now you've fastened your seatbelt after repeated requests from the pretty hostess, looked around and are tapping your fingers. The plane has taxied away from the base and is RIGHT NOW, about to take off.

The pilot up front, after receiving clearance, enables the necessary switches, checks that the gauges and instruments are all right, and in one fluid move, moves the thick lever (that sits between the pilot and the co-pilot) forward.

Pause.

Now. Moving the big bad lever forward. The lever is connected via a cable to a sensor system. The sensor is simply a device that 'reads' how much the lever has moved forward and in turn, sends an electrical signal to another system. (Warning: For the uninitiated, this is gonna be like Inception, only with a lot more levels)

Zoom in on the electrical signal. It is just a potential difference (in layman's words, Voltage) that exists between the wire and parts that are not connected to it.

The cable goes through a lot of other systems (filters, digital signal processors, etc which one needn't bother about), and reaches the main control computer. The computer, in turn is made up of a couple of hundreds of integrated circuits (ICs), connected together via metallic wiring etched onto a circuit board or as normal cables. Our voltage signal that set off from the sensor attached to the Big bad lever, has reached one of these ICs in the tiniest fraction of a second.

Zoom in to one of the ICs. The signal is processed and the computer now knows the pilot has engaged the lever. Now, during the time the IC was made, it has been taught to do its job, by programming a lot of code into it. This code now resides INSIDE the IC and is continuously running, monitoring any incoming signals and doing what must be done. Zoom in, fellas.

The code that we talked about, was written in some programming language, compiled and finally 'burnt' onto the IC in a way the machine can understand. Zooming in again, you see a tiny slab of Silicon on which a lot of etching, metallisation and doping is carried out. Now, on this slab are billions of transistors, which are the building blocks of an electronic circuit. To give you an indication of size, each transistor is around a few nanometres (that's one 100,000,000th of a metre) across. Zoom in. These transistors store a tiny bit of charge in a part of their body called the 'floating gate'. Depending on whether this charge exists or not, each transistor is considered to be on or off, and thus, (lo and behold) comes the 1 and 0 that we know in binary. No it's not over yet.

When the program was written, by a geek sitting miles away in some airconditioned office, he did it in something like C. The thing got translated from all those "int main(void)" stuff to hexadecimal code that looks like rows of rows of something like like 0xABCD12340. And THIS code is stored as BINARY, as those little ones and zeroes indicated by the thousands of electrons that store the charge in each transistor.

(Remember, it is just a few hundreds of microseconds since the pilot moved the Big bad lever high up in the cockpit..)

ZOOM IN.

Inside each transistor are thousands of electrons, flowing across 'junctions' that came into being when they were being 'fabricated'. (The beauty of the whole thing is, all this is exactly under our control). Now, once the signal had reached one of our computer's ICs, a part of the signal goes through these transistors, and automatically, a particular piece of the IC, which handles what must be done when the lever is being engaged, gets activated. This is how the code works, deep inside.

Plane --> Pilot --> Lever --> Sensor --> cables --> Computer --> IC --> flip flops --> Transistors --> gate-charge --> electrons.

Zoom out (whew).

A couple of hundreds of transistors actually form the inside of a few dozen flip flops, which are set to perform what the computer wants to do. The flip flops have been triggered, and they generate a control signal that (zoom out) goes out of the IC we talked about, through a lot of cables, onto the actuator system.

The actuator system has a lot of electrical power circuits connected to the engine to control its firing. The signals that reach the actuator undergo a similar electron-driven transistor-poking, and a few microseconds later, a power signal hits the engine control unit. The engine control unit now assumes power, and begins conducting its own show... Zoom out to watch!

The drama begins. The compressor sucks in air, as millions of air-molecules from outside. The fuel is drawn from the pipes, and the valves are instructed to open, admitting a spray of fuel into the jet turbine engine. Simultaneously, the control unit has initiated (think electron-transistor-powerAmplification again) the sparking system in the same engine to fire. The spark happens. A chemical reaction between the hydrocarbon in the fuel and the air, molecule-by-molecule, happens.. and the highly charged aviation fuel ignites, sending a mass of hot gases out through the engines back.

Zoom right out. Out and out, to the first layer.

*static* "You have control."

ONE SECOND or so after the lever has been moved forward, the pilot smiles smugly hearing the whirr of the engine slowly building up, gaining amplitude, to what is pretty loud inside and definitely a deafeningly friggin LOUD roar outside. Every fraction of a second is being monitored and controlled by the onboard computer, and the maze of wires, cables and copper strips are kept ever busy by the (deafening?) sea of electrons that are sent from one place to another, in some way, completely under human control.

The engines build on power and a few seconds later, the aircraft is pushed forward by one giant invisible hand of hot gases, rapidly building speed till the tyres lift off the ground and the big bird is airborne.

All this in a few seconds of your life.

So the next time my dad gets started onto me about "looking at life in the proper perspective", I'm gonna get him to read this post.

15 comments:

/urgu said...

It is mind-boggling, isn't it? You've been as accurate as possible without actually delving into the minutae. If you think in terms of input and output, a flow of invisible, practically massless particles causes a goddamn AIRCRAFT to fucking FLY! If that isn't surreal, I don't know what is.

I experienced the very same feeling when I was going home for midsem vacations. We had just been taught Power Systems, and so I kept marvelling at the minds that could contemplate such intricate and roughly precise power distribution methodologies. Really, as Atlas Shrugged puts it, modern machinery and technology are WAY better monuments than normal architectural wonders.

It is this sentiment that ought to be inculcated in engineering students, this sense of wonder and awe at minds far more superior than oneself. I promise a blog post on this.

Balu Raj said...

Awesome post mate. Engineer you are my friend and one heck of a perspective to have:)

*movie ideas looming*

infernal-tranquility said...

Whoa!

Its not everyday you come across engineering students who actually know and care a damn about how the course is finally implemented.

Ahem.You only come across specimens like myself in abundance.. :P :D

So..Respect! ;)

Sriram said...

@guru: Totally, man! It's the sense of wonder. And, this morning I was looking at the trees opposite my house, thinking.. and a plane that flew by started the train of thought.

@balu: Had I been Jiji CV, I'd have talked about this on the first day of class :P #justsaying

@akanksha: Heya.. welcome :) Not exactly a bloggy topic to have read as the first post, but anyway :D Thanks for dropping by!

Akshay Mallan said...

mind boggling. esp when you come to the point when you realise that this is jus one of billions of actions taking place every second on this earth

totalliemeh said...

I used to like aeroplanes. tch.

Vivek said...

Haha!Nice one bro. Engineering is so intriguing at times dont you think ;) Also, Id love to have the recipe of that coffee that you had.

P.S. I'm disappointed that you din't go into how that combustion actually takes place :P

Sriram said...

@Mallan: Well dude I was thinkin of writing this based on the dippy, but thought people would connect better with a plane :D Thanks for stopping by!

@chyech: Tch. lol :D

@vkm: Man when I was writing this I discovered I didnt know how exactly a jet engine works, beyond the obvious stuff. Hence the lack of detail. And combustion is chemistry, I shall not step into that, goddammit!

vanwinkle said...

Whoa man u make me wish i d taken up apec,this is totally badass:D and the thing u experience during take off is exhilarating,to put it mildly.. and as for your assertion about this being caffeine fuelled, i m inclined to ask:dude,what ve you been smoking?

Man u ve made a blazing re entry into blogospher,cheers!

Gautam Sasi said...

Hmmm..speechless mach...Wen u said something mindboggling ws up and about i surely dint expect u to pull up something lyk dis..Seems u made it a point to reply to one of my queries the other day..Well seems i lurve Engg now..;)

Gautam Sasi said...
This comment has been removed by the author.
hollowmaniac said...

Weed. Macha. Very weed post. I likey. I likey. Awesomeness. No long comments like guru,brajesh,vivek n the like. I just likey. Awesomeness indeed. Very.

Srivardhan said...

Beautiful post, bro! 'admire the way you've nurtured your spirit of inquiry! Lucid narration and excellent perspective!

As NatGeo puts it, 'Live Curious!' :)

Anonymous said...

A good article Thank you!

Mahadev said...

"@balu: Had I been Jiji CV, I'd have talked about this on the first day of class :P #justsaying"

priceless !! sums up everyting in the blog ! :D