To NP, Aleph name , particle physics ?

[akira]

Hi Nelson,

Slightly off topic but I was wondering if the name Aleph was coming from the detector in particle physics. Since you have a patent named supersymmetry, it would be a stange coincidence ...

Akira

[icceman]

Apparatus for LEP pHysics

[massimo]

First letter of the Hebrew alphabet, I think...

[Christer]

No I rather think that Nelson is a mathematician or a theoretical
computer scientist. NP is one of the most important classes of
computational problems, the problems that can be solved in
non-deterministic polynomial time, and the hebrew letter aleph
is used to denote cardinality of infinte sets: Aleph_0 is the
cardinality of countable infinite sets like the integers and
the rationals, Aleph_1 is the cardinality of the reals and then
there is an infinite sequence of more and more infinite infinities.

[vdi_nenna]

aleph null

Aleph-null is the cardinal number of the set of Integers.
(There are as many positive integers as there are both positive and negative integers, and that is Aleph-null. Aleph-null plus aleph-null equals aleph-null.)

http://www.bsu.edu/web/jcflowers1/rlo/mathnumbers.htm

[Christer]

Originally posted by vdi_nenna
aleph null

0 with a / through it.

You're probably right. It's a long time since I took discrete math.
So, change to Aleph_1 and Aleph_2, in my previous posting.

[vdi_nenna]

I'm no math wiz. I remember it from some math class and always thought it sounded cool.

Cool name for a band maybe...

[Sch3mat1c]

Isn't that usually spelled alpha?

Tim

[Dennis Hui]

Originally posted by Christer
No I rather think that Nelson is a mathematician or a theoretical
computer scientist. NP is one of the most important classes of
computational problems, the problems that can be solved in
non-deterministic polynomial time, and the hebrew letter aleph
is used to denote cardinality of infinte sets: Aleph_0 is the
cardinality of countable infinite sets like the integers and
the rationals, Aleph_1 is the cardinality of the reals and then
there is an infinite sequence of more and more infinite infinities.

After hanging around here a while, I now think of NP as initials for
Mr. Pass as opposed to the complexity class.

BTW, the cardinality of the reals is often denoted 'c' (continuum).
The conjecture that c=Aleph_1 actually turned out to be one
of the strangest problems in mathematical logic. (This is
the so-called 'continuum hypothesis'.) Whether this
is true of false (and here's the fun part) turned out to
depend on whether you work in a logic system
which includes something called the Axiom of Choice.

Dennis

[xsnailx]

i have just done search in goggle and
http://www.moonromance.net/storyview.php?storyid=7193
check this one out