
The Disappearing Physicist and His Elusive Particle - sctb
http://nautil.us/issue/13/symmetry/the-disappearing-physicist-and-his-elusive-particle
======
atemerev
"A child prodigy, capable of doing cubic roots in his head as a kid"

I'll teach you. I used to do that when I was 10. Easy enough.

Let's say you want to take a cubic root from 148877. Looks scary enough?

First, look at the last digit. It's 7. Map it through the following
correspondence:

1 -> 1, 2 -> 8, 3 -> 7, 4 -> 4, 5 -> 5, 6 -> 6, 7 -> 3, 8 -> 2, 9 -> 9, 0 -> 0

(basically, each digit maps to itself, except (2, 8) and (3, 7) which map to
the other one in the pair).

So, the last digit of the cubic root of 148877 is therefore 3.

Now, erase the last 3 digits. You are left with 148. To figure out the first
digit of the answer, you have to memorize the cubes of 1 to 10, you probably
already know most of them:

1, 8, 27, 64, 125, 216, 343, 512, 729, 1000. (You probably know 343 from Halo
series, and 729 is 1729
([http://en.wikipedia.org/wiki/1729_%28number%29](http://en.wikipedia.org/wiki/1729_%28number%29))
without one, so the only hard thing here is 216).

So, 148 is between 125 and 216. Take the lesser one, 125 is 5^3. So the first
digit is 5.

The answer is therefore 53. It only works with two-digit numbers, but with
some practice you can do it in seconds.

Now go impress someone.

~~~
sampo
> _So, the last digit of the cubic root of 148877 is therefore 3._

So your algorithm only works for numbers that are cubes of an integer, right?

~~~
araes
I believe the first digit trick still works with off-numbers, but the second
digit trick definitely fails, as it depends on tricks of cubics.

1=>[1], 2=>[8], 3=>2[7], 4=>6[4], 5=>12[5], 6=>21[6], 7=>34[3], 8=>51[2],
9=>72[9], 10=>100[0] (or 0=>[0])

Basically, if you memorize the first 10 cubics, then you can do the next 10
cubics (and actually, there's probably a trick for doing all the integer ones
recursively)

If you're really good at this trick, I'm sure you can bound non-integer
numbers with referenced cubics and then do something like Newtonian descent.

Its kinds of like building a lookup table of lookup tables in your head for
integer cubics.

------
roywiggins
"he carried into adulthood the concomitant problems in relating to others—and
very pertinently to women—ensuring the prerequisite internal pool of
frustrations essential for lateral thinking"

I don't think this follows at all, honestly. Frustration begets more
frustration, not lateral thinking.

~~~
InclinedPlane
Indeed. Richard Feynman is the classic lateral thinker but he didn't exactly
have a problem relating to women.

~~~
thret
This comment was screaming for an xkcd:
[http://xkcd.com/182/](http://xkcd.com/182/)

------
MaysonL
<<There are several categories of scientists in the world; those of second or
third rank do their best but never get very far. Then there is the first rank,
those who make important discoveries, fundamental to scientific progress. But
then there are the geniuses, like Galilei and Newton. Majorana was one of
these.>> —(Enrico Fermi about Majorana, Rome 1938)

quoted in Wikipedia

~~~
femto
The story is just begging for a Dan Brown style book: a missing genius, a
Majorana codex containing the secrets of the Universe, the power that goes
with knowing those secrets, a secret Illuminati with connections to Galilei
and Newton, a connection to the Cosa Nostra, throw in a Roman/Vatican
connection, a WWII connection... A rip roaring novel (with screen rights) is
in there somewhere!

