
The Corpus Christi Prime - mkeeter
https://friendlyfieldsandopenmaps.com/2017/09/08/the-corpus-christi-prime/
======
eadmund
I was curious about this:

> Finally, I generated random fluctuations in the number and tested each with
> the Miller-Rabin primality test. This produced a shortlist of numbers which
> were very very likely to be prime. I used Dario Alpern’s fantastic tool to
> determine whether any of them actually were prime.

I thought that in crypto one normally just repeats Miller-Rabin enough times
that it's infinitesimally improbable that the candidate isn't a prime, and
that the reason for doing this is that it's too expensive to actually prove
it. This indicates that it's now feasible to just prove that a number is
actually prime; should crypto libraries now switch to a different method of
ensuring primality?

~~~
krastanov
From an engineering point of view it really does not matter. The chance that
the probabilistic algorithm fails is so insignificantly small, that cosmic
rays hitting your CPU registers is probably a bigger problem.

From a mathematical/CS point of view, indeed it was a fairly recent, and
fairly pleasant discovery that the primality testing algorithm can be
derandomized while still retaining its low complexity (it was suspected for a
long time, but proving it was awesome).

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martinmj
If you enjoy watching videos with prime numbers, you may try to watch some of
these - [https://goo.gl/Gvr7Yd](https://goo.gl/Gvr7Yd) \- it's 11 hours of HD
entertainment. :)

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kafkaesq
This guy's pretty cool. Check out his modular multiplication tables:

[https://friendlyfieldsandopenmaps.com/2017/09/07/beauty-
in-m...](https://friendlyfieldsandopenmaps.com/2017/09/07/beauty-in-
mathematics-modular-multiplication-tables/#more-55)

~~~
theoh
Visually reminiscent of
[https://en.wikipedia.org/wiki/Munching_square](https://en.wikipedia.org/wiki/Munching_square)

More recreational math from Cambridge students here:
[https://www.archim.org.uk/publications](https://www.archim.org.uk/publications)

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maximilianroos
Would there be a way of doing this systematically? i.e. input an image and
find a prime that represents it?

~~~
ehsankia
Here is one script [0] that was posted on Github yesterday, I believe a few
others have been popping up ever since this video [1] by Numberphile on
Thursday.

[0]
[https://github.com/jorants/PrimeImage](https://github.com/jorants/PrimeImage)

[1]
[https://www.youtube.com/watch?v=fQQ8IiTWHhg](https://www.youtube.com/watch?v=fQQ8IiTWHhg)

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l0b0
Cue logo_prime_finder.py in 3…

~~~
ehsankia
[https://github.com/jorants/PrimeImage](https://github.com/jorants/PrimeImage)

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sarreph
A more challenging 'edition' is to find a number that spells out one of its
prime factors.

But then, that long number wouldn't be a prime, so it's more like prime-
ception. :)

~~~
madez
That isn't very difficult. Choose a prime, say 2. Now pick a sufficiently
large number of digits to get a high enough resolution. Pick a number that
graphically spells out 2. Replace the least significant bit of the number with
a zero. You are done.

In general, "fixing" a number such that it is divisible by a given prime is
easy.

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wglb
Shades of Carl Sagan's Contact!

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Rapzid
What's going on in the upper left there? :)

~~~
clemParis
The first paragraph of the articles says "The top left corner encodes my
initials, JRH, in ASCII. The bottom right corner is my date of birth."

