

First glider discovered in a cellular automata on an aperiodic tiling - tim_hutton
https://plus.google.com/110214848059767137292/posts/ZBdwythH2RF

======
ForrestN
This looks fascinating; any chance someone can easily explain the significance
of the terms and the image? Seems daunting to look everything up and try to
understand as a layman.

Edit: Awesome, thanks everyone! <3 HN

~~~
devindotcom
A 'glider' is a self-propagating pattern generated in Conway's Game of Life.
It's a basic simulation of complex behavior using a grid governed by simple
rules made to suggest isolation, reproduction, and overpopulation. These
simple rules produce some incredibly complex patterns, some of which can be
likened to creatures. The 'glider' is a very basic one that travels in a
relatively straight line and can be used to activate or transmit information
between other patterns.

One actually showed up drilled into the side of a new retina Macbook Pro; I
wrote it up for TechCrunch (with suitable woolgathering):
<http://techcrunch.com/2012/06/23/laocoon/>

This Game of Life uses a totally different grid style, which changes the
patterns that emerge and the math involved. This guy has created a glider for
a rhomboidal grid environment, and that's... pretty cool.

~~~
melloclello
Hey man I gotta say I dug that writeup - did any more information surface
regarding whether that pattern is indeed inside _every_ retina Pro?

~~~
devindotcom
No word on that - not very many people want to drop two large on a laptop and
then peel back every layer. But I'd say if we see it even once more that's a
sign that it's probably a constant. Glad you liked the article.

------
pax
haha, I just found an Google Easter Egg, while reading this thread :)

> Google "Conway's Game of Life"

PS. Also, somebody posted it on HN 3 weeks ago, but got no love:
<http://news.ycombinator.com/item?id=4224926>

------
SilasX
How exactly did they go about proving that it continues to glide forever,
despite the lack of periodicity? Is there some finite combination of
subsequent tile groups in aperiodic tilings, such that you just have to show
that all of them involve a transition another part of the glider cycle?

~~~
Pinckney
Watch the cyan tile carefully in the animation. It always propagates to
adjacent rhombi across edges, all of which are parallel.

------
nraynaud
isn't this pattern the 2D projection of a periodic 5D pattern ?

what would it mean for the glider's path in 5D (well, 6D with time) ?

~~~
tim_hutton
Yes, I think that's right. This page talks about De Bruijn's pentagrids
method, which uses the same rhombi ribbons as the glider travels on as the
axes of the 5D space: <http://www.ams.org/samplings/feature-column/fcarc-
ribbons>

Five possible directions for the glider to travel in = Five dimensions of
space.

(Is that right?)

------
pohl
Awesome! For years I have had a desire to see "life" on a penrose tiling. Are
there more examples out there?

------
tim_hutton
New Scientist wrote an article on this:
[http://www.newscientist.com/article/dn22134-first-gliders-
na...](http://www.newscientist.com/article/dn22134-first-gliders-navigate-
everchanging-penrose-universe.html)

------
jongraehl
This explanation of the work the automata rule needs to do was interesting:
<http://mrob.com/pub/math/quad-grid-glider.html> (from g+)

------
blaines
I have to sign in to read this? =/

~~~
dangrossman
You have to sign in because you're signed in to a Google account but not
Google+. If you were either signed in to Google+, or not signed into Google at
all, you would see the article without a sign-in prompt.

~~~
tsahyt
That's just plain stupid and annoying. I didn't notice yet since I've
abandoned my Google Account a few months back and am therefore not signed into
Google at all.

However, why do they do that? Hasn't it occurred to them that not everybody
with a Gmail Account wants to be on G+?

~~~
lmm
>Hasn't it occurred to them that not everybody with a Gmail Account wants to
be on G+?

Of course it's occurred to them. Why else would they be trying to force them?

