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This is amazing. Thank you.


Probably not. Knowing the speed-of-light round trip time to a network location gives you a bound on how much you can improve the performance of remote operations.

For example, I'm in Austin, querying a database hosted in Amazon's us-east-1 data center ("Northern Virginia"). Call it 1000 miles away, 2000 mile round trip.

    You have: 2000 miles
    You want: millilightseconds
            2000 miles = 10.736388 millilightseconds
If I have a query that's taking < 1ms, no optimization of how that query is executed by the database can possibly improve the overall performance.


  MCMLXVII + LXV
   = MCCCCCCCCCLXVII + LXV (canonicalize)
   = MCCCCCCCCCLXVIILXV    (concatenate)
   = MCCCCCCCCCLLXXVVII    (sort)
   = MCCCCCCCCCLLXXXII     (combine, VV => X)
   = MCCCCCCCCCCXXXII      (... keep combining, LL => C)
   = MMXXXII               (... C{10} => M, nothing left to combine)
   = MMXXXII               (optionally, look for ways to re-write with the subtraction rule)


I originally thought canonicalize was an important step, but it actually isn’t for humans. For humans, CCCCCCCCC requires a lot more tedious counting than CM or even DCCCC, leading to more errors than simply allowing the human to notice that CM+C=M.


I think the practical way of thinking would be:

- seeing L + L = C and converting CM to M ( basically striking L L and C )

- then V + V = X, ( striking Vs and add an X)

Then write whats left:

MMXXXII

Then try to re-write.


I choose to believe it's a prophecy, foretelling the coming of a Universal search engine that will someday make that joke stop working.


All hail the universal search engine!


You're recalling a different incident: engine-out problems are a routine part of flight training at every level.

You're thinking of https://en.wikipedia.org/wiki/United_Airlines_Flight_232

where so much of the plane broke that they had to invent a new way to fly it.

I can't turn up a reference right now, but like you say, in the next few years that failure was repeatedly simulated, and all the simulated planes crashed.

(IIRC, Haynes declined to try his hand at any of the simulations, explaining that the one time when it really mattered was enough for him.)


Looks like Wikipedia thinks they also simmed the Gimli Glider incident with other aircrews, though it may well be wrong: https://en.wikipedia.org/wiki/Gimli_Glider#cite_note-19

Flight 232 is another very interesting story, for sure.


You're right, thank you.


Certified Programming with Dependent Types

http://adam.chlipala.net/cpdt/


You'll also need to know that e^x = sum{0 -> infinity} x^n / n!.


Not so stupid: Start with the phrase "Hoteling's rule" for a century of academic analysis of that question.

If you own an oil field, you have to balance a number of factors:

* How is the price of oil changing, relative to overall inflation? You mentioned this one.

But also,

* Are technological improvements (either increasing the total amount of extractable oil in the world, or outright oil replacements) going to dramatically lower the price if I wait too long?

* Is it still going to be my oil next year, or am I going to be first against the wall when the next revolution comes?

My (unsophisticated, outsider) opinion is that if you see oil-producing countries selling as quickly as they can, that's weak evidence that they're worried about the last two bullets.


I enjoyed it: not a sports fan, knew little of baseball except that the one game pro game I've seen in person was super-boring [to me].

_Moneyball_ isn't about baseball so much as it's about how easy it is for humans to be tricked by our intuitions and habits. Moneyball talks about baseball from the point of view of someone who everyone just assumed would be good -- and wasn't -- as he's trying to make more and more objective assessments of players, and wielding his conclusions against competing, more traditional managers.


It's because "latitude lines" aren't really lines in this context (except the one at the equator).

If you took two points from one of those latitude "lines", you'd always be able to find a shorter path between them than the path along the latitude. If you take the shortest path between the two points and extend it all the way around the sphere, you'll end up with a great circle. That great circle is an actual "line" in this geometry.

https://en.wikipedia.org/wiki/Spherical_geometry


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