Why Is the Pentagon a Pentagon? | Hacker News Reader

Why Is the Pentagon a Pentagon?

smithsonianmag.com

156 pointssohkamyung129 comments

It was obviously designed to be a cunning way of limiting the expansion of the military-industrial complex; they can't just keep building adjacent pentagons because they don't tesselate.

I had always assumed it was the single exposed face of a mostly subterranean dodecahedron.

That is correct, but the subterranean dodecahedron itself is merely the portal that the interdimensional lizard beings use to move between our world and the 4-dimensional hyperdodecahedron.

Your comment made me check if it actually was possible, and what the platonic solids in higher dimensions were.

http://math.ucr.edu/home/baez/platonic.html

https://en.wikipedia.org/wiki/120-cell

There's also this fantastic Numberphile: "Perfect Shapes in Higher Dimensions"

https://www.youtube.com/watch?v=2s4TqVAbfz4

At last, I've found the end of the internet!

But they do in 3 dimensions.

Is the future of the Pentagon the Dodecahedron?

The Pentagon might actually just be the top face of the massive subterranean Dodecahedron.

I don't see the problem with including the occasional courtyard among adjacent pentagons, though.

Perhaps the military was a fan of Roger Penrose, and really did want to expand. Or perhaps they intended to tile the entire world with a geodesic grid.

They would be building adjacent hexagons, to follow the curvature of the Earth. There would be at most 11 other pentagons.

For those who don't get this - it is a clever reference to Euler's Twelve Pentagon theorem : "any closed polyhedron composed no polygons other than hexagons and pentagons and having no holes must have exactly 12 pentagons."

They can just keep adding concentric rings, and the military-industrial complex expands exponentially with each new one.

(Pedantic/educational): quadratically (ignoring the bending of spacetime due to the mass of the military-industrial complex)

That's also assuming that the thickness of each ring is constant. If they increased the thickness by a certain percentage relative to the previous band, then you'd have exponential growth.

But the existing rings are equal-width, and wider rings do not make sense (the buildings would get less and less daylight)

Fair point. I guess there's another assumption, that the rings are built at a constant rate. In fact, if we make the typical assumption that the economy grows exponentially (which might hold for all but the longest term models), it could be possible to build newer rings at an exponentially faster speed by constructing more and more of them simultaneously.

even more pedantically: sub-quadratically since it's being built on a positively curved manifold. As the Pentagon approaches the size of a hemisphere, growth will stop and then reverse.

If they wanted to add concentric rings, then they screwed up big-time by sticking the thing next to a river.

Though with the military budget, rerouting the river shouldn't be that hard to do. But the river also constitutes the boundary between Virginia and DC, so there may be political problems with that.

I always thought it was kind of weird choice. You'd think one of the requirements for your primary military building would be that you wouldn't want it to be easy to pick out from the air by potential bombers. Especially in WWII, when aerial bombardment was such a major part of the war, and such bombing relied heavily on visual recognition of the target. But the Pentagon isn't just architecturally distinctive, but is so in such a way that's primarily appreciated from above, and than they named it to draw attention to the fact. (the article does mention that this objection was at least briefly considered during the buildings planning).

And indeed, the building was bombed from the air in 2001. One wonders if the 9/11 hijackers would've chosen it as a target if it wasn't so easy to pick out by eye.

Probably because the US hasn't had a foreign army on its soil since like...1812

Pearl Harbor, although pedantically maybe that was just an air force/navy instead of an army.

Pedantically? If we take your new definition, how many countries is the US currently invading with its airforce (particularly drones)? It isn't invading them because it's armies aren't in them and that's what the term "on its soil" means.

Well, the parent was talking about _bombing_, so Pearl Harbor is a reasonable point.

The Japanese also used ground troops to take over several Aleutian Islands during WWII.

Pancho Villa's raid on Columbus, NM, a few decades earlier was clearly an army, and well after 1812.

But you don't need a foreign army around to launch bombing raids. The Doolittle raid (US bombing of Tokyo in response to Perl Harbor) was only a few months in the future when the Pentagon was started.

> Perl Harbor

That's when Ruby overtook Larry Wall's language, right?

Yeah, but then Larry dropped a couple nukes on Matz.

> Probably because the US hasn't had a foreign army on its soil since like...1812

Inserting the clearly implied "hostile" before "foreign army", that's still off by more than a century, since we had one in 1916, even if we only consider the CONUS and so exclude some things in WWII.

The US faced a hostile foreign army on CONUS in 1916?

Pancho Villa's Division of the North attacked Columbus, NM, provoking the Punitive Expedition.

The last time there was a flagged and uniformed foreign military on US soil was in 2005. The Mexican army assisted with aid work in the aftermath of Hurricane Katrina.

https://en.wikipedia.org/wiki/Mexican_response_to_Hurricane_...

I would think https://en.m.wikipedia.org/wiki/Holloman_Air_Force_Base#Germ... has uniformed German military and flies German flags.

I think "and hostile" was implied.

The aerial bombing in WW2 was so spectacularly inaccurate that being the aiming point was possibly safest place to be. It was the fires that did the most damage. For something that consumed so much resources it is very contraversial - not helped by German production going up during the period of heaviest bombing.

Before the Pentagon, the largest office building in the world was the Luftwaffe headquarters[1]. Unlike the largest synagogue in Berlin, tt was not damaged by Aerial Bombardment.

[1] https://en.wikipedia.org/wiki/Detlev-Rohwedder-Haus

Thanks!

There is a good book on the topic by Richard Overy, The Bombing War. It left me with the impression that the bombing morphed into vindictive civilian punishiment.

There's something to be said for the emotional value of a recognizable symbol for the most powerful military in the world.

"But as a symbol... As a symbol, I can be incorruptible, everlasting." - The Batman

"Did you think to kill me? There's no flesh and blood within this cloak to kill. There is only an idea. And ideas are bulletproof." -V

There is a certain irony, given that "The Pentagon" has become at least roughly synonymous with, "Unbelievably bloated and corrupt". If the F-35 were a privately funded venture, everyone involved would have probably shot themselves.

Business fails all the time usually does not result in seppuku. The problem with government bloat is the lack of death for the business, not its purveyors. The plane is not built by the government, but Lockheed Martin, a private company. If government cut funding a while ago, they would've stopped working on the plane.

To be clear, I was hyperbolically trying to make that exact point... I'm not truly suggesting death as an option.

> Unbelievably bloated and corrupt

Pretty sure that impression is government in general: elected politicians, pensioned workers, IRS, public utilities, etc.

Of which the largest government body is... the military. "Healthcare" is the largest expenditure, but largely to a collection of unconnected private industry... the military is a different matter.

US intelligence in 1940/1941 had a pretty good idea that the Germans were nowhere near the ability to build a bomber that could make the flight from France to the US east coast and back. Reference:

https://en.m.wikipedia.org/wiki/Amerika_Bomber

Building something with significantly more range than a B-29 (which at that time existed as preliminary blueprints only) was something they knew the Germans were nowhere near.

> "It is one of the most recognizable buildings in the world"

Why do the USA press and people insist that if it's famous in the US it's famous in the rest of the world? I only guess it looks like a pentagon but for non-English speaking countries (most of the world) I wouldn't say it's one of the most recognizable buildings.

Just do a quick google search (probably with anonymous browsing/VPN?) of "famous buildings" and you'll see it's nowhere near them.

Edit: if you can read this (English + HN) you and your friends/family are most likely not part of the rest of the world, but I agree that I messed up confusing famous with recognizable.

Actually for me, a citizen of a non English speaking country, it is. On the same level with the Eiffel Tower and Big Ben.

Same here. Any movie remotely related to the cold war (or just any conflict involving America) will probably have dramatic views of the Pentagon, often with "The Pentagon" as a caption.

There's a difference between being "an attraction" and "recognizable".

I get your point, but the pentagon is pretty recognisable if only because it's often the backdrop of news reports. That and it's a giant pentagon.

"backdrop of news reports" what? Maybe in the USA, not anywhere else.

in the backdrop of news reports originating in other countries about the USA

I'm getting down voted to oblivion, but in the UK Ive never seen a uk news reporter stand in front of the pentagon. Nore a French reporter. Maybe it's a USA thing?

>>backdrop of news reports

And films, don't forget the films. That is probably how most people know of The Pentagon.

"most recognizable" and "famous" are correlated but not identical. The pentagon is not simply well-known, it's also very recognizable because - well, because it's a huge freakin' pentagon, and there aren't many other buildings that look anything like it.

Same applies to lesser-known Frank Gehry buildings, as one example. Many people might know the Guggenheim Bilbao, but might look at the much less well-known DZ Bank building in Berlin and think "that must be a Gehry!"

If you saw a picture of it (remember, it's shaped like a pentagon), would you recognize it? I'd bet yes, making it recognizable.

Why do certain non-Americans insist on acting like our famous stuff isn't? It's ok if people know some of our stuff, it doesn't diminish you.

They're more than likely American, I know me and a few others have gone through phases of randomly pointing out common "misconceptions" like that to my fellow citizens! Mostly harmless

European here. Never even been to the US.

I'd say that as famous buildings go, the Pentagon is up near the top of my passive vocabulary - instantly recognizable and nameable. Washington, D.C. is rich in those.

But actively? No. If tasked with naming ten or twenty world famous buildings, I simply wouldn't think of it. Eiffel Tower, Sydney Opera House, the Pantheon (oh yes), and somehow, Word Trade Center, even if it is no more, but no Pentagon would occur to me.

[Edit: The usual typos]

You'd put The Pantheon above The Parthenon? Or do you too suffer from my problem of having to check which is which?

I'd put the Pantheon obove the Parthenon, yes. For one thing, it is - magically - a functioning building, which just happens to have been going for 1800 years.

I do know the difference :-)

It's great - I assume the hole had a cover of some sort as a damp day makes it less functional (though just as impressive).

>instantly recognizable and nameable. Washington D.C. is rich in those.

I'm curious as to what other instantly recognizable and nameable buildings are in Washington D.C. to a non-American. I can think of the Pentagon and the White House. I can't really think of any others I would think a non-American would immediately recognize and be able to name. The Capitol, maybe? The Washington Monument?

I'm also wondering, with time, if the rebuilt World Trade Center will become just as recognizable. It certainly is striking in the Manhattan skyline, but it just doesn't seem "the same" to me for some reason I can't put my finger on.

Lincoln and Jefferson Memorials, respectively. (American, guessing from the recognizable structures that show up in our cultural exports)

That just about sums it up, yes. Not too bad for one city.

Nope. I couldn't identify those, and I visited DC when I was about 14.

The Washington Monument (the big obelisk thing?), the White House, and the Pentagon -- the last as much because it's used in the news in the same way that "10 Downing Street" is, but unlike a London street, the Pentagon is a unique, distinctive structure.

They are commonly shown in tv and films but I doubt many outside the US could actually name them.

And they're on our currency :)

That Obelisk thing and the house with the Lincoln figure in it that is in the same park (or whatever).

That park or whatever: https://en.wikipedia.org/wiki/National_Mall

"Recognizable" is not the same thing as "famous."

As the article mentions, the Pentagon was a target in the 9/11 terrorist attacks. So, a billion people have probably seen it on TV.

Its continuos involvement in international politics since the Cold War made the Pentagon universally famous (mostly in the bad sense). Also, its milimalistic fascist-like architecture makes it more easily recognizable than other simmilar symbols like the White House or the Kremlin (who actually knows what the Kremlin looks like?).

Many Westerners are under the impression that St. Basil's Cathederal is the Kremlin. It's a bit like thinking that the Washington Monument is the White House.

https://en.wikipedia.org/wiki/Saint_Basil%27s_Cathedral

The Kremlin is a whole bunch of buildings, kind of like the Tower of London. It contains multiple palaces and churches, built over the course of ~400 years, in somewhat of a variety of architectural styles. What it looks like depends on which of those buildings you're looking at.

Before I had seen it myself, I knew the name but I would not have recognized it from pictures.

If you had pictures of ten different buildings and knew that one of them is called Pentagon would you be able to reason which one that might be?

Maybe because I am German I wouldn't connect the word "Pentagon" with the geometric shape. In German a Pentagon is a "Fünfeck".

In some sense you don't have to recognize the Pentagon to know it when you see it. Everyone knows that the words "the Pentagon" are used as a metonym for the US military, and it's pretty much the only pentagonal building. So if you saw a pentagonal building you'd say "Hey I bet that's the Pentagon" even if you'd never seen it before.

Correct. It had absolutely nothing to do with the representation of masonic principals through architecture. Niether does the washington monument. Masons have had absolutely no influence on american federal buildings. All that symetry and numbers stuff happened purely by chance.

For the pentagon, I have seen no evidence to the contrary, but the rest of your statement is wrong. Sorry I don't have time to go on a chase for citations for you, but there is plenty of evidence of Masonic influence (not that this is a bad thing) on the general layout of the DC area.

I forget. HN has no concept of humor. Absolutely ever word in this place is to be taken literally.

Oh, sorry, my sarcasm detector is broken... always has been. One of my greatest weaknesses. Oops.

Which, to be fair, is a large part of why it is what it is. There are plenty of spaces where sarcasm, cynicism, and humor are not discouraged. There's something... peaceful about HN's norms.

yes, that sense of analness, like half the time you are talking to Sheldon Cooper.

Sarcasm doesn't translate to text very well at all. The comments that come after when people are mistaken about the lack of/use of sarcasm are pretty pointless and detract from actual discussion.

It does where readers understand the conventions. Repetition of words or absolutes points to sarcasm. "I never smoked pot" or "I have absolutely never ever under any circumstances even been in the same room as pot."

Repetition of words with similar meaning is also a common literary and oral communication technique for emphasis of important points you want the audience to take away.

So, yeah, it can indicate sarcasm, but it can also indicate the exact opposite. It oral communication, tone would usually disambiguate between the two intents.

Humor, which includes sarcasm, is the only one of those you won't find here in spades. One could drown in the cynicism.

It has been long established that sarcasm and text communications go together about as well as peanut butter and urine.

Citation please?

I choose to interpret this as a humorous jab at another of HNs endearing norms.

Wait for it ...

The entire top comment thread belies this statement. HN humor just has a particularly nerdy bent, in a way entirely unlike the bleeding sarcasm you'd find on, say, Reddit.

If you divide the globe into hexagons there's only one missing piece and it'll only fit a pentagon. the pentagon is the centerpiece of that grid. no units can land on it.

I was under the impression that the pentagons would be 12, care to elaborate how it's only one?

e.g. http://math.stackexchange.com/questions/2121175/is-it-possib...

my bad :)

You're not allowed to talk about the others.

source?

I was wrong about just the 1 pentagon.

http://stackoverflow.com/questions/749264/covering-earth-wit...

I always assumed it was a reference to the pentagonal shape of many star forts (despite not being a star shape itself).

I assumed it was a reference to the five armed service branches, but I was wrong.

Note that at the time of construction there were only four - the Air Force was established post-WWII.

My totally unresearched guess was that it referred to the five armed services: Army, Navy, Air Force, Marines, Coast Guard.

"Because that was the shape of its originally intended building site" is so delightfully mundane.

That's probably a side-benefit. If it had been an irregular pentagon (or any other shape), the inter-service rivalries would still be going on about who has the better office space (not kidding - you think vicious politics is only on capitol hill?)

Yet sometimes the simplest answer is the best if not correct one. My pot roast story tells it well, http://selfdefinedleadership.com/blog/?p=158

don't overlook the obvious

Counterpoint by H.L .Mencken: "Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong."

Construction complete Jan 43 Air force birthday Sept 47. Plausible to plan for it, but unlikely.

Indeed. I thought it was a reference to many pentagonal forts from the Middle Ages, like Castel Sant'Angelo on the banks of the Tiber.

https://upload.wikimedia.org/wikipedia/commons/e/eb/Castel-S...

They didn't stop building pentagonal and star forts in the Middle Ages. Some of the most important fortifications in US history are pentagon plus bastion star forts.

https://en.wikipedia.org/wiki/Fort_Sumter#/media/File:Fort_S...

https://en.wikipedia.org/wiki/Fort_McHenry#/media/File:Fort_...

I figured it was just in reference to how often the USA/Military uses 5-pointed stars on things.

Obviously it's a pentagon because the shape allows it to contain Yog-Sothoth. Have you people never read Illuminatus!

Not everyone can see the fnords

I was going to say something along the lines of a pentagram being too obvious, but your explanation wins!

"Are you really keeping him in the Pentagon?" https://books.google.com/books?id=gnO76vZELmQC&lpg=PA356&ots...

tl;dr: because it was designed for a weirdly shaped parcel of land, but then it wasn't put there, but they stuck with previous designs anyway, because the president thought it was a neat design .

17 months to build it; 17 years to renovate it!

I'm sure the renovation was also many times the cost of construction.

It is a lot harder to modify a building that is in use. Plus, pork.

A plane did crash into it partway during that renovation.

> 17 months to build it; 17 years to renovate it!

So kind of like software, then.

"17 months to build it;"

They wrote the pentagon in Scala?

Well, they weren't trying to continue using it during construction...

It was going to be a circle, but there were 5 rounds of cuts.

surprised no one noticed this: a circle encloses the greatest area with the smallest circumference (a fundamental calculus of variations result). A pentagon being a crude approiamtion of a circle , is more efficient than a square building, which means less building materials. A a pentagon-shaped building is also structurally stronger than a square building.

Build as it is the saving is minimal if any at all. It's donuts, not a circle.

> A a pentagon-shaped building is also structurally stronger than a square building

That isn't the case for the Pentagon. It's not a single, simple, unbroken structure and does not meaningfully benefit from that premise. The Pentagon is a lot of building segments connecting to form a shape. It would be equally strong as a whole had it been built in the shape of a rectangle or square.

I thought I recall reading someplace that the angles and the walls constructed from them created some kind of auditory dampening/scrambling effect so that sounds did not emanate out from the structure in any intelligible way. That may have all been speculation of sorts, I can't recall the source I got that impression from :(

Wasn't the Pentagon meant to be made into a Library post war? That's why the floors were so thick and sustained less damage from the plane impact.

Its so you can renforce one side, so when a missile hits it on 9/11 it wont do loads and loads of damage!

She felt the need to use the word absurd.

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