[Edu-sig] busy with Martian Math...

kirby urner kirby.urner at gmail.com
Sun Aug 1 00:31:35 CEST 2010

```I'm packaging up some Python for a next course that I'm teaching
(a relatively busy summer for me).  I've also got the J language in
the docket. The computer lab is all state of the art Macs, so
we'll see how we fair with IDLE.

I've appended some source code I just wrote in the last hour, while
watching a geometry show on public TV (math-dimensions.org --
on Portland, Oregon's cable network these days).

The source won't run without an additional dependency though,
which I call stickworks.py -- features in some of the Showmedo
episodes and other places.  This module provides simple Vector
and Edge classes for working with VPython (another dependency).

The course materials I'm developing may be previewed at this URL:

(cover page index.html not yet crafted)

I will conclude with a repost of something I just posted to my little
engineering list, headquartered at the so-called Pauling House
(Linus Pauling's boyhood home), FYI.

Keith was a presenter at OSCON this year, regarding his Server Sky
idea (orbiting server farm) while Allen Taylor is the esteemed author
of 'SQL for Dummies'.

====

Re: [wwwanderers] Mars aressync orbits

OK, thanks to both Keith and yourself for all the discussion.  I'd not
seen that "fourth power" argument before, but then this literature is
fairly alien to me.

Back on planet Earth (and Keith's gardening concerns), I was just
seeing on public TV about how Salem has yet to permit urban farmers to
keep chickens.  I'd just assumed that chicken coops were legal
throughout the Willamette Valley, silly me.

I caught this show while waiting for another public TV show about
hyper-dimensional geometry.  We were informed that higher dimensional
spaces "really exist" base on the analogy that if two dimensional
beings can think about three dimensions, then so should we, be able to

As a database guy, my bias is to think of n-tuple addressing as just a
fancy way to store/retrieve records, like URLs for storing/retrieving
web pages (there's a reason it's called hypertext).  Sure, you can
come up with fancy analogies to polyhedra, but I'm not sure this
"really exists" argument is important to the mathematics.  Seems more
like mysticism (or even organized religion).

In any case, the Martian Math I'm busy concocting has a different
meaning of "4D".  I thought it was poetic that I was working on my
uploads at the same time I was catching this Earthian Math show on
public television.

Kirby

On Sat, Jul 31, 2010 at 2:07 PM, Allen Taylor <allen.taylor at ieee.org> wrote:

Kirby,

The magnetic launcher you are thinking of works because of hyper-fast
acceleration. This causes two problems:

1. Any organic matter, such as us would be turned into jelly.
2. High velocity at ground level would cause tremendous heating due to
atmospheric friction, even with Mars thin atmosphere.

The magnetic launcher makes sense on the Moon, which has a negligible
atmosphere, but only for cargo that can stand thousands of g's.

The pendulum from Phobos as well as the Lofstrom Loop are viable for
Earth to orbit or Mars to orbit because velocity is low at ground
level where the atmosphere is densest and because g-forces are
relatively moderate.

Allen

====

"""

by K. Urner for Saturday Academy, Martian Math

Summer camp 2010 @ Reed College

"""

from stickworks import Qray, Edge, getedges
from visual import *

def setscene ( ):
"""set the stage for our little drama"""
scene2 = display(title='Drawing a Duo-Tet Cube',
fullscreen= True, autoscale = False,
background=color.white, scale = vector(0.1, 0.1, 0.1))
return scene2

def ccp(  ):

"""
draw 12 spheres around 1
"""

scene = setscene( )
scene.select( )

# 26 points in space (as sums of Qrays)
a, b, c, d = Qray((1,0,0,0)), Qray((0,1,0,0)), Qray((0,0,1,0)),
Qray((0,0,0,1))
e, f, g, h = -a, -b, -c, d
i,j,k,l,m,n = a+b, a+c, a+d, b+c, b+d, c+d
o,p,q,r,s,t = i+j, i+k, i+l, i+m, n+j, n+k
u,v,w,x,y,z = n+l, n+m, j+l, l+m, m+k, k+j

# 12 around...
for locus in [o,p,q,r,s,t,u,v,w,x,y,z]:
ball = sphere(pos = locus.xyz, color = color.orange, radius = 0.5)

# 1 at the center (nuclear ball)
center = sphere(pos = (0,0,0), color = color.red, radius = 0.5)

print "OK, done..."
return

if __name__ == "__main__":
ccp( )
```