
Ancient Islamic Penrose Tiles (2007) - prismatic
https://www.sciencenews.org/article/ancient-islamic-penrose-tiles-0
======
Zaheer
In case anyone missed it a few days ago - a game based on Islamic architecture
was posted [1]. I've downloaded it and its really quite fascinating. Even with
the geometry laid plain in front of me I'm still always amazed at the tiling
and final outcome.

[1] [http://www.engare.design/](http://www.engare.design/)
[https://news.ycombinator.com/item?id=15546761](https://news.ycombinator.com/item?id=15546761)

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macawfish
Looks like prior art to me

~~~
Someone
You would have to show that they at least knew, and preferably, could prove,
that these patterns can tile the plane.

~~~
partycoder
You would probably need a time machine, going back to the Siege of Baghdad and
look for a proof before the Great Library of Baghdad was destroyed by the
Mongol Empire.

At least we do have proof that they understood the law of refraction, but we
still call it Snell's law instead of Sahl's law.

Maybe the Mayans knew about it too and we will never know thanks to the idiot
known as Bishop Diego de Landa, that burned all thousands of years worth of
knowledge present in the mayan codices for containing "satanic" glyphs.

~~~
candiodari
Nealy every civilization lost their repositories of knowledge at various
points in their history. Usually what gets destroyed is not just the
knowledge, the books itself, but the priests, monks, librarians, ... around it
get massacred too. In all but a few civilizations, it only needed to happen
once. In all where it only needed to happen once, it happened, through various
means. Most often, it was an internal civil war. Other times it was external
military conquest and plundering.

Greek, Roman and Western Judeo/Christian knowledge survived. Not because we
never had civil wars that tried to destroy/eradicate it, or had plundering
armies ransack libraries, but because there were 10 copies and only 6 or so
got destroyed (or in some cases all but one). The copies happened because
since the 4th century or so the Church decided to dedicate quite a few people
to copying all knowledge (all knowledge, not just Christian) (and before the
church state-sponsored educational groups did it). But the amount of effort
should not be understated: you have to understand that this was first
thousands then tens of thousands people entire lifetimes dedicated to nothing
other than creating backup copies of physical documents, a massive cost to an
economy that was a LOT smaller than today's.

The point is, most civilizations develop scientific knowledge. And they
advance rapidly during the formative years of the civilization. Then things
get frozen, and vested interests both prevent further research, limit access
to existing research, and effectively lock up scientists, librarians, etc.
Western civilization (and the Roman empire and a few Greek city states before
it) did not do so, and instead dedicated large amounts of economic activity to
science. This is completely exceptional, and of course, this is the reason
that you're complaining about it, in the sense that you wouldn't be
complaining about it had this not happened.

You should also keep in mind that the Mongol Empire advanced while driven by
hunger, and Bishop Landa by overpopulation and lack of economic opportunity in
Europe. The control those people had over whether or not to destroy things was
very limited or even nonexistent.

For those various reasons blame should not go to the Mongol Empire or Bishop
Landa, or any other conquering tribe/nation/country/..., blame rests with
Islam and Mayans for the loss of this knowledge. They restricted and locked up
their scientific knowledge, to the point of not having backups, and then their
point of control over that knowledge got destroyed, along with all the
knowledge.

Probably, a few families in those empires got to enjoy a very powerful
position for a few centuries and in trade the entire state structure that
millions depended upon got utterly devastated, including probably quite a few
of those people.

There is a famous incident where the Caliph of the Islam has a written
exchange with the remaining Crusader kingdoms, in what is today Lebanon. The
exchange is the kings telling him that if he continues his attack, it may well
succeed, but it would destroy the agricultural base that fed the millions of
Muslims under his rule ... he acknowledges this, states that allah will feed
them ... then attacks ... thousands die in the attack, and millions die from
the resulting famine. The vast majority of the dead ? Muslims. Odds are good
that the Caliph simply did not have the control necessary to stop the assault.

~~~
benbreen
I can't tell if your comment is in good faith, but reading it charitably, it
seems to me that you have gotten your information from a highly biased source.
If we blame the Mayans for Cortez or the Persians for Genghis Khan and
Tamerlane, then we might as well blame the librarians at Alexandria for not
preserving their texts off-site, no?

At any rate, on the Christian monastic tradition and its roots in scribal
cultures that were rooted in the eastern Mediterranean, you might want to
check out the works of Peter Brown - _The World of Late Antiquity_ is from
1971 but is still an interesting read.

And on the deep history of knowledge exchange between the two sides of the
Mediterranean, this Wikipedia page is a good start:

[https://en.wikipedia.org/wiki/Islamic_world_contributions_to...](https://en.wikipedia.org/wiki/Islamic_world_contributions_to_Medieval_Europe)

The Crusades is the famous binary, but when you dig down into actual sources,
you end up in unexpected places, like one of the greatest philosophers of the
Middle Ages (Maimonides) living happily as a Jew in Cairo, or the hugely
inventive and experimental medical school in Norman Salerno which drew on
Christian, Jewish and Muslim works, or Cordoba under the Ummayads, or the fact
that Grosseteste, Bacon and other founders of medieval empiricism were
directly engaging with writings on optics and chemistry from the Islamic
Golden Age (which, incidentally, were better preserved in the eastern
Mediterranean than in the Christian west)... the list goes on.

~~~
candiodari
Nope. I do not blame the Mayans for Cortez. But I do blame them for losing the
knowledge that Cortez destroyed. If it wasn't Cortez (or as some see it: a
civil war caused by the local population being confronted with Cortez showing
them an alternative _)

For that same reason that I'd blame the person who lost their bitcoins by a
phone falling in the water:

If it wasn't that event, something else would have happened and destroyed that
knowledge. It's not the fault of the disaster, rather of the inadequacy of the
measures taken to prevent disasters, whatever they are, from taking it out.
You cannot prevent disasters from happening at all, so you must simply be
ready for them, and there's no excuse for not being ready.

The difference between civilizations with lasting scientific progress and
those without is not Cortez, or flooding, or ... it's whether they had backups
of their knowledge and whether they spread it. Most didn't, and knew perfectly
well that they didn't. They simply preferred having a small group that had
power solidified into that power forever, and locked up everything including
their scientific progress, to that end. That's what happened to Mayan
scientific progress. That's what happened to Islamic scientific progress,
that's what happened in a LOT of places.

_ this is the big missing link in most stories. Why is western civilization
destroying indigenous tribes, e.g. in Africa ? Mostly (I'm not claiming there
were no atrocities, there were. And they're no OK, they are not the major
cause of the destruction though) because their members would much rather be
westerners than tribe members ... That's the local perspective and this does
not seem to be well understood in the West. Life in indigenous cultures is
mostly boring, short, and painful. It has a few positives that we in the west
may or may not have lost, but in general individuals in the west live a lot
better than members of indigenous cultures. That, of course, causes a
systematic "leak" of individuals choosing to "join the West", rather than
maintain their indigenous customs. Often just partially.

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rwnspace
If you find this kind of thing compelling, I recommend 'Finding Moonshine' by
Marcus Du Sautoy. I mostly enjoyed it for the anecdotes about John Conway, but
in any case, it's a good layperson book about mathematics, symmetry, monstrous
objects and pretty things.

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radiorental
A video of them being made

[https://www.youtube.com/watch?v=t-n03ano-
Ak](https://www.youtube.com/watch?v=t-n03ano-Ak)

