The Kendall Band at the subway station on campus had been rusting away, with only the chimes — the part they call “Pythagoras” — working. The other parts, “Kepler” and “Galileo” I have never seen working in all the years I have been here. Then one day “Pythagoras” too was gone for repairs. They posted this note for half a year until suddenly, it was back!

“Pythagoras” is two identical sets of eight pipes that could be struck by seven different mallets each. The mallets are controlled by a bar that could be swung back and forth by an attached handle which the user controls on the platform. Before the repairs, I had never paid attention to its intricacies, partly because there was not much time to play with them in the time before the next train arrived, and partly because the old rusty version didn’t make great sounds and I thought they were just some randomly sized pipes. Plus, the handle lacked fine control, and the best one could do was to hopefully transfer as much energy as possible to even get the thing going.

When it came back new, it was looking much like a real instrument and now I wondered what else you could do with it besides swinging the handle back and forth like most people do. Surely you could play an actual melody, right?
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Dell Releases Latitude Z With Wireless Charging

Could just use a docking station.

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The New York City subway, in analogy to New York City itself, is an old rat-infested hole prone to breakdown and teetering on the edge of operability. Its layout and signage are illogical but somehow comprehensible, its margin for error is just not there … yet, somehow it manages to run. Dirty, smelly, hot in summers, and generally contemptible, it is oddly alive and orderly. People not only put up with it, they adapt to it.

This is one of the nicer stations. Still looks like a 19th century dungeon, though; which of course, it is.

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I have a good guess now of how cell phone number porting is implemented. Had a number transferred from AT&T to Sprint. The phone actually came with a randomly assigned number and a matching MSID (mobile station id), but Sprint told me to re-program the phone with the desired number and a new non-matching MSID in the area code of the desired number.

The porting process was as follows:

• Immediately, random number stops working, new Sprint-assigned MSID works as phone number!
• Within minutes, AT&T cuts off connection and accounts access to old number, which ceases to work.
• Hours later, MSID stops working as phone number, old number now rings new phone.

The fact that the MSID works as a phone number during porting and remains in the phone’s settings, must mean that it is in fact the true “phone number” identifier for the phone. The phone just gives out its stored “phone number” for the purpose of outgoing calls. I’m guessing every carrier has a pool of phone numbers in each area code to give out, and there is a static allocation database somewhere. During porting, Sprint assigns a new number from its own pool, which becomes the MSID. Then AT&T (who owns the old number) changes its databse to forward calls to the old number on to Sprint, instead of processing them internally. Finally, Sprint changes its database to take those incoming calls and forwards them to the assigned MSID.

When you get a new line, a number from the carrier’s pool is assigned so no forwarding is needed, and that must be why the MSID matches the phone number in that case.

Now, if I were to port again to a third carrier, what would they do? Maybe they’ll look up the number and discover they should talk to AT&T?

Here’s some real information which I haven’t read but maybe corroborates or discounts what I wrote. http://www.syniverse.com/pdfs/GuidetoWNP6thedition.pdf

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