Comment by jgrahamc | Hacker News Reader

Comment by jgrahamc | Hacker News Reader

"What will future civilizations think of Manhattan Island when they dig it up and find a carefully laid out network of streets and avenues? Surely the grid would be presumed to have astronomical significance, just as we have found for the pre-historic circle of large vertical rocks known as Stonehenge, in the Salisbury Plain of England. For Stonehenge, the special day is the summer solstice, when the Sun rises in perfect alignment with several of the stones, signaling the change of season."

No, if they notice this they'll go: "Any grid on the Earth's surface has the same effect, it's just question of the angle" and then they'll be quiet about it. Stonehenge is interesting because its alignment is specific to the solstice so anyone digging it up can see that it was built for a purpose. Manhattan on the other hand doesn't seem to have any specific purpose from an astronomical perspective and if you look at the shape of the island you'll see that the avenues were built parallel to the long 'sides' of it. So, I hope future people will be sensible and not start looking for some astronomical significance to Manhattan.

Tyson has enough street-cred as a skeptic

http://www.skepticality.com/neil-degrasse-tyson/

that I'm sure his tongue is firmly in his cheek when he writes of future civilizations speculating on cultural reasons for Manhattan's grid alignment.

By the way, I especially like the last paragraph of the submitted post, which assumes a readership mostly in the temperate zone of the Northern Hemisphere: "While we are on the subject, when viewed from all latitudes north of the Tropic of Cancer (23.5 degrees north latitude), the Sun always rises at an angle up and to the right, and sets and an angle down and to the right. That's how you can spot a faked sunrise in a movie: it moves up and to the left. Filmmakers are not typically awake in the morning hours to film an actual sunrise, so they film a sunset instead, and then time-reverse it, thinking nobody will notice."

Tyson had a funny bit when he recently appeared on the Daily Show - he noted that the spinning Earth at the beginning of the show was spinning backwards.

Any examples of this on YouTube? What movies have sunrise scenes long enough to see sun motion?

Plenty of movies have time-lapsed scenes of the sun going up and coming down. Vampire movies are a notable example, because of the significance of the sun. I'm pretty sure "Blade" had a couple of examples.

Films featuring people trapped and forced to survive in the desert are probably also good candidates. And some romances where the couple watch the sun set on a beach, or possibly watch it rise having had that "first talk" all through the night.

...which assumes a readership mostly in the temperate zone of the Northern Hemisphere...

should be: which assumes a film industry mostly in the temperate zone of the Northern Hemisphere

GUYS! I am pretty sure those little Stonehenge references are are just humor. The author is not REALLY suggesting that future civilization would be puzzled by Manhattan's grid. The comparisons with Stonehenge are just an amusing way of pointing out this phenomena that many people are probably not aware of.

Personally I think it is pretty cool that the perfect conditions for observing this are only available in a few cities - despite the fact there must be a lot of cities around the world with skyscrapers and grid like street plans.

If everything is the same every year, though,

> Future anthropologists might conclude that, via the Sun, the people who called themselves Americans worshiped War and Baseball.

doesn't seem entirely implausible to me. (Of course, the anthropologists would be in error, it's just vaguely reasonable if you haven't seen anything else.)

"For 2012 they fall on May 29th, and July 12th" and "These two days happen to correspond with Memorial Day and Baseball's All Star break".

More mystic crap. Memorial Day in 2012 is May 28, not May 29 and the MLB All Star Break beings July 9. Neil deGrasse Tyson shouldn't even write like this, getting drawn into mystical interpretations, even in jest, just reinforces the idea that it's worth thinking about crap like that.

Believing in mysticism might be crap, but it's certainly worth thinking about. Anthropological study of belief is highly valid and valuable. Even in jest.

Memorial Day observed is on the 28th. Actual memorial day is on the 29th according to my calendar.

I'm pretty sure this is an article that has been updated for years. It probably fell perfectly on those dates early in the series, then the deviations weren't enough to sacrifice the humor later on.

a classic well-actually (see http://tirania.org/blog/archive/2011/Feb-17.html)

Agreed. I ignored the hyperbole about future anthropologists and took this as tips for photography in Manhattan.

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