
Was Alan Turing right about mechanism behind tiger stripes? - digital55
https://www.quantamagazine.org/20130325-biologists-home-in-on-turing-patterns/
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gilgoomesh
The article doesn't actually mention the specific Turing paper. It's "The
Chemical Basis of Morphogenesis":

[http://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphogen...](http://en.wikipedia.org/wiki/The_Chemical_Basis_of_Morphogenesis)

It should be noted that Turing was a mathematician, not a scientist. He wasn't
trying to prove that tiger stripes occur in a specific way but instead he
wanted to model mathematically how such large scale structure _could_ arise
from uniform homogeneous structure.

~~~
unwind
The article _linked to_ a PDF of the paper in question, in the first opening
paragraph. That's pretty decent.

Also, isn't mathematics considered a science? What?

~~~
gilgoomesh
Oops, I didn't see the link. My mistake, then.

Is mathematics a science? I always say "no" but there are different
definitions (it's an old word and originally just meant "knowledge").

Abstract fields like mathematics are certainly excluded from the purer
definition of "natural sciences" (physics, chemistry, biology, geology)
because it doesn't require interaction with the physical world.

Relevant xkcd:

[http://xkcd.com/435/](http://xkcd.com/435/)

Mathematics is sometimes called a "formal science" but the term isn't widely
accepted. In general: if it doesn't follow the scientific method (which
requires experimentation, which mathematics doesn't include) it isn't
considered a science. Some mathematical fields do experiment; computational
and statistical mathematics can employ stochastic experimental procedure –
making them scientific or at least science-like – but they're still abstract
and certainly not natural sciences.

~~~
wolfgke
> Mathematics is sometimes called a "formal science" but the term isn't widely
> accepted.

In German this kind of science is denoted as "Strukturwissenschaft"
(structural science) to close mathematics and theoretical computer science off
(empirical) sciences.

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demallien
Is this news? I don't know about anyone else, but ever since my undergrad
days, I see repeating patterns in nature and I just say to myself "oh, there's
another partial differential equation"

~~~
amelius
I guess most of nature is described by differential equations, starting with
fundamental physics. So in the end, that statement does not add much. It is
the kind of differential equation that actually matters. In this case it is a
non-linear DE, which means that it is probably not really a fundamental
process, but a more complicated, derived process.

Besides, there are also non-repeating patterns in nature that are governed by
differential equations. Very basic examples are the temperature across a
heated room, and the voltage across a resistor.

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rch
> (FGF) serves as the activator, and a gene variant dubbed Sonic hedgehog
> (Shh) acts as an inhibitor.

"SHH is the best studied ligand of the hedgehog signaling pathway. It plays a
key role in regulating vertebrate organogenesis"

\--
[https://en.wikipedia.org/wiki/Sonic_hedgehog](https://en.wikipedia.org/wiki/Sonic_hedgehog)

~~~
agumonkey
May I be downvoted, but I was just opening
[http://www.sonicstadium.org/music/](http://www.sonicstadium.org/music/) when
reading your comment.

Turing coincidence.

