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Physics stream

Craig — Wed, 21 Nov 2007 16:54:24 GMT

Gregg's friend Carl is a physicist his old company hired to come up with new ethanol formulations. He's a full bore stream of consciousness emailer like somebody else I know before they gave up on email :)

========================================

Gregg,

I also thought you'd be amused to find out that despite my not believing in special relativity, my software simulation of Einstein's gravity will be used to help teach grad students at MIT (see below).

Also, there is a full on food fight going on in the physics community with the publication of this paper:
http://arxiv.org/abs/0711.0770

and I think I can connect to it with my preon theory.

Max Tegmark <tegmark@MIT.EDU> wrote:

    CC: Max Tegmark <tegmark@mit.edu>, Enectali Figueroa <enectali@mit.edu>,
    Edmund Bertschinger <edbert@mit.edu>,
    "Scott A. Hughes" <sahughes@mit.edu>, Edwin Taylor <eftaylor@mit.edu>,
    Andrew J S Hamilton <ajsh@origins.colorado.edu>
    From: Max Tegmark <tegmark@MIT.EDU>
    To: Carl Brannen <brannenworks@yahoo.com>
    Subject: Re: River model of black holes and Painleve orbit simulation.
    Date: Sun, 4 Nov 2007 12:55:00 -0500

    Hi Carl,



    Please accept my sheepish apologies for not getting back to you sooner - your message unfortunately slipped through a crack in the spacetime continuum, and I only read it now.



        The wikipedia said that you taught GR with the "river model"

        of black holes.

    I did indeed, in course 8.033.

    Because of this, I suspect you will enjoy

    showing your students my Java simulation,



    Many thanks for pointing me to this! It looks very useful indeed, and I'm sure I'll use it next time I teach GR. I'm not teaching it again anytime soon, but I"m forwarding your email to a few others who I think will like it: Enectali Figueroa, who's teaching it this semester, my GR colleagues Ed Bertschinger, Scott Hughes & Ed Taylor, and to my old friend Andrew Hamilton, one of the river model pioneers.

    Thanks again,

    Max

    ;-)

    --------------------------------------

    Prof. Max Tegmark

    Dept. of Physics, MIT

    70 Vassar Street Rm. 37-626B

    Cambridge, MA 02139







    Carl Brannen wrote:

    Dear Dr. Tegmark,



    The wikipedia said that you taught GR with the "river model"

    of black holes. Because of this, I suspect you will enjoy

    showing your students my Java simulation,

    which does both Painleve and Schwarzschild coordinates.

    It's set up to automatically step through a series of demonstrations

    of various attributes of gravity. The student can halt the

    demonstrations and edit the initial conditions:



    http://www.gaugegravity.com/testapplet/SweetGravity.html



    Right now I've got 8 or 9 demonstrations, but they're easy

    to insert and I keep adding more.



    The comparison between the behavior of Painleve and

    Schwarzschild coordinates is, I think, very convincing.

    I can't see why people would still want to use Schwarzschild

    after seeing Painleve in action.



    The simulation uses equations of motion defined by

    varying the integral of ds rather than by going through

    the Christoffel symbols. This gives just three differential

    equations instead of four, and it turns out that the

    Painleve metric is fairly simple when written this way.

    That is, it's a sum of radial and angular acceleration

    divided by powers of the radial distance.



    The Schwarzschild equations of motion are a sum of

    powers of the radial distance r, and the distance to

    the event horizon, r-2. The calculation for Schwarzschild

    equations of motion is messy, and putting it into

    reduced form is worse. I used MAXIMA as I tend

    to lose minus signs and the like.



    Since the simulation is written as equations of motion,

    it works equally well with massive and massless

    particles (and tachyons).



    Carl Brannen

More from Carl

Craig — Wed, 21 Nov 2007 16:55:34 GMT

From: Carl Brannen [mailto:carl@brannenworks.com]
Sent: Saturday, November 17, 2007 6:29 PM
To: Gregg D. August
Subject: Re: Pencil

Gregg,

I'm not sure I told you this, but there is a massive amount of

work going on related to a paper out by Garrett Lisi a week ago:

http://arxiv.org/abs/0711.0770

This is based on the group E8, and it seems to work well with

my stuff. It's being argued about on the web. For example, see

neutral commentary here:

http://backreaction.blogspot.com/2007/11/theoretically-simple-exception-of.html

anti commentary here:

http://motls.blogspot.com/2007/11/exceptionally-simple-theory-of.html

and pro commentary here:

http://www.physicsforums.com/showthread.php?t=196498

My own contribution to this is a Java applet for the E8 roots

here:

http://www.measurementalgebra.com/E8.html

The above Java applet is now being downloaded at the rate of nearly

once per minute. I'm going to release an improved version later

tonight.

Carl

First post

Craig — Wed, 21 Nov 2007 16:45:26 GMT

I'm at the top of the fractal (is that possible?). Nice navel. Dive, dive, dive!!

where have all the clannies gone?

patty rubin — Fri, 17 Aug 2007 15:50:37 GMT

:-(

and our fearless leader?

snugbug

what next for the rumpus room ?

fractalnavel — Sat, 03 Feb 2007 19:18:05 GMT

my main focus was getting a few extra adventures, so that stuff will stay. but what about the remaining equipment ? thoughts ?

currently i'm saving up for the skillclaw game, but after that, i was thinking comfy couch. that leaves a spot for a meat tree. is 1000 meat a day worth it, for an investemetn of 200k meat ?

clan focus (sort of)

fractalnavel — Sat, 03 Feb 2007 20:00:11 GMT

i set this up mainly to get as many extra adventures as i could ~~eek~~ eke out of the system. kind of a private experience, as it were. but if anyone else wants just that, fine.

beyond this, i'm open to any non-conflicting suggestions.

forum skinning

fractalnavel — Sat, 03 Feb 2007 19:31:59 GMT

the appearance & layout here really needs help. ideas ?

how do you want the clan karma system to work ?

fractalnavel — Sat, 03 Feb 2007 19:15:31 GMT

for now, i'm just leaving it off. this clan is not really for item exchange. ideas ?

no, no, no, no, no, ...

fractalnavel — Sat, 03 Feb 2007 19:07:56 GMT

... yes.

ok, i'll try setting up a forum here for the KoL clan "Void of Antientropic Mechanism". i've never really run a forum before, and the cs version of this is a little odd, so bear with me. anyway, here it is. happy posting, and we'll evolve from this very modest begginning. or not.