Article View: sci.math.symbolic
Article #1075Re: Another factorization request.
From: Lambert Meertens
Date: Sun, 16 Nov 1986 16:22
Date: Sun, 16 Nov 1986 16:22
76 lines
4994 bytes
4994 bytes
In article <2380002@hpsadla.HP> jimh@hpsadla.HP (Jim Horn) quotes from the
"Canadian Farm & Home Almanac" the following "Argument Clincher":
> The possibility of two persons having identical fingerprints is one chance in
>
> 1606937974174171729761809705564167968221676069604401795301376.
The number quoted is suspiciously close to 2^200 =
1606938044258990275541962092341162602522202993782792835301376.
That would correspond to twenty yes/no fingerprint characteristics for each
finger. The question remains where the middle segment of digits comes from.
One guess is that someone determined the leading digits using a six-place
log table, the final digits using modular arithmetic, and proceeded to fill
in the rest at random, thinking no-one would bother to check it out.
Another possibility is that the (human) computer really goofed in doing the
arithmetic. I tried to reconstruct a scenario in which the number is
obtained by repeated doubling in decimal arithmetic while being subjected
to a few random errors in the digits. The simplest I could find (but I did
not try that hard) is given below. A "v" stands for an assumed error. I
have no idea if the number of v's is significantly lower than needed to
explain an arbitrary random middle segment.
22300745198530623141535718272648361505980416 = 2^144
vvvvvv v
22300745198530624250645715272648361505980416
-------------------------------------------- * 2^3
178405961588244994005165722181186892047843328
vvv
178405961588244994005165722270186892047843328
--------------------------------------------- * 2^4
2854495385411919904082651556322990272765493248
vvv
2854495385411919904082651556323700272765493248
---------------------------------------------- * 2^2
11417981541647679616330606225294801091061972992
v
11417981541647679616330606225294802091061972992
----------------------------------------------- * 2^1
22835963083295359232661212450589604182123945984
v
22835963083295359232661212450589604282123945984
----------------------------------------------- * 2^2
91343852333181436930644849802358417128495783936
v
91343852333181436930644849802358417158495783936
----------------------------------------------- * 2^1
182687704666362873861289699604716834316991567872
vvv
182687704666256873861289699604716834316991567872
------------------------------------------------ * 2^2
730750818665027495445158798418867337267966271488
v
730750818665027495445158798418867337268966271488
------------------------------------------------ * 2^1
1461501637330054990890317596837734674537932542976
vvv
1461501637330054990890317596837734674538002542976
------------------------------------------------- * 2^4
23384026197280879854245081549403754792608040687616
v
23384026197280879854245081549403754792608030687616
-------------------------------------------------- * 2^13
191561942608124967765975708052715559261044987392950272
vv
191561942598124967765975708052715559261044987392950272
------------------------------------------------------ * 2^23
1606938044174171889601405952376674162141676069604401795301376
vvv
1606937974174171889601405952376674162141676069604401795301376
--
Lambert Meertens, CWI, Amsterdam; lambert@mcvax.UUCP
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Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: arc1-ca.pugleaf.net!utzoo!mnetor!seismo!mcvax!lambert From: lambert@mcvax.uucp (Lambert Meertens) Newsgroups: sci.math.symbolic Subject: Re: Another factorization request. Message-ID: <7148@boring.mcvax.UUCP> Date: Sun, 16-Nov-86 11:22:06 EST Article-I.D.: boring.7148 Posted: Sun Nov 16 11:22:06 1986 Date-Received: Sun, 16-Nov-86 21:13:06 EST References: <2380002@hpsadla.HP> Reply-To: lambert@boring.uucp (Lambert Meertens) Organization: CWI, Amsterdam Lines: 75 Summary: 2^200 with some pseudo-random digits Apparently-To: rnews@mcvax