

Slime mold grows network just like Tokyo rail system - j_baker
http://www.wired.com/wiredscience/2010/01/slime-mold-grows-network-just-like-tokyo-rail-system/

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10ren
A fun experiment with a striking result.

The environment provided for the slime molds doesn't seem to record mountains
and lakes etc, so they can't be expected to choose the same system.

When we find that engineers and nature have arrived at similar solutions, I
think it's the engineers that we should marvel at.

Even soap bubbles organize themselves to minimize surface area.
<http://www.soapbubble.dk/en/bubbles/geometry.php> and apparently _Centuries
ago, architects discovered that experimenting with soap bubbles could help
them define the most economical form for the actual structure._
<http://www.encyclopedia.com/doc/1G2-3407500197.html>

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RiderOfGiraffes
Dup: <http://news.ycombinator.com/item?id=1071568>

Although as so often happens, the first submission sinks without a trace, a
subsequent duplicate submission gets an upvote on the "newest" page, makes it
to the front page and thereby gets noticed generally. This is one argument to
suggest why the duplication detection algorithm should not be tightened
significantly - if a link has any real merit, and it's news rather than
something old that someone has run across, then it has several chances of not
being missed, becuase it will get submitted several times.

Earlier submissions of the same story also sank (mostly) without trace:

<http://news.ycombinator.com/item?id=1071533>

<http://news.ycombinator.com/item?id=1071093>

~~~
Confusion
The submission could also be counted as an automatic upvote, achieving the
same effect, while still allowing tightening of the duplication detection
algorithm. One article with two votes is better than two articles with one
vote. For low numbers of votes, I guess it shouldn't matter the first few
votes are old.

~~~
ars
"The submission could also be counted as an automatic upvote"

It does already. If submit a url that is already there, it gives it an
automatic upvote.

~~~
Sukotto
That's only worthwhile if you also reset the time decay. upvoting something
old has virtually no impact on its chance of moving to the front page

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zemaj
I don't get it...

It's this just a variant on the shortest path problem. Even a bad solution is
going to look similar to a real rail network. There are plenty of good, easy
algorithms to solve this, much faster than waiting a day for slime to grow.

Confused as to how this got in Science & Wired. What am I missing (I didn't
read the Science report, so maybe there's something there?)

~~~
jvdh
It's actually a lot more like the travelling salesman problem, for which there
are no algorithms (well, some heuristical algorithms).

~~~
Sukotto
It's actually more of a traveling salaryman problem :-)

------
ambition
_Like the slime mold, the model first creates a fine mesh network that goes
everywhere, and then continuously refines the network so that the tubes
carrying the most cargo grow more robust and redundant tubes are pruned._

Hey, that's like how brains mature!

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dtegart
I attended a lecture about this at Oxford. It has also been done for Britain's
railway system and came quite close to the post-Beeching layout.

~~~
jermy
A recent paper uses it to model the UK Motorway network -
<http://arxiv.org/abs/0912.3967>

Any references to the work on using slime to mimic the UK rail network that
you mentioned? The best I could find was the following from
<http://www.springerlink.com/content/7tw4745823645128/>

"In practical terms such a process may also be witnessed in the evolution of
real infrastructure networks, such as British railways following the Beeching
reviews in the early '60s [8,9]. In these reviews, the flux along various
routes was measured and routes with too low a level of traffic, mainly branch
lines, were targeted for closure. At the same time, major routes were
strengthened to cope with the expected source-sink relationships for both
passenger and freight traffic. Interestingly, the reports focussed on
efficient rather than any explicit consideration of resilience, which may
explain the sensitivity of the current UK rail network to disruption."

Where: [8] British Railways Board: The development of the major railway trunk
routes (1965) [9] British Transport Commission: The reshaping of british
railways - part 1: report (1963)

~~~
dtegart
I can't seem to find anything either. It was part of Silicon Valley comes to
Oxford 2009 if that helps your search.

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JCThoughtscream
I wonder if this applicable to city planning? Constructing a plexiglass
landscape in miniature, scattering a few flakes in the right places, then
letting loose the mold... let nature calculate maximum efficiency for you!

~~~
blasdel
<http://en.wikipedia.org/wiki/MONIAC_Computer>

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ax0n
This is cool, but the headline looks like something written for Fark!

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naz
My, that looks like a yummy slime mold!

~~~
obneq
Aloha obneq, welcome to NetHack! You are a neutral male human Tourist. You are
in non-scoring discovery mode. What do you want to zap? [p or ? _] You may
wish for an object. For what do you wish? slime mold q - a slime mold. What do
you want to eat? [b-jq or ?_ ]

My, that was a yummy slime mold!

