APOD: Manhattanhenge: A New York City Sunset (2014 Jul 06)

[APOD Robot]

Manhattanhenge: A New York City Sunset

Explanation: This coming Saturday, if it is clear, well placed New Yorkers can go outside at sunset and watch their city act like a modern version of Stonehenge. Manhattan's streets will flood dramatically with sunlight just as the Sun sets precisely at each street's western end. Usually, the tall buildings that line the gridded streets of New York City's tallest borough will hide the setting Sun. This effect makes Manhattan a type of modern Stonehenge, although only aligned to about 30 degrees east of north. Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21, the only two days that the Sun rises and sets due east and west. Pictured above in this horizontally stretched image, the Sun sets down 34th Street as viewed from Park Avenue. If Saturday's sunset is hidden by clouds do not despair -- the same thing happens twice each year: in late May and mid July. On none of these occasions, however, should you ever look directly at the Sun.

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[geckzilla]

This was back in the day before Neil did Cosmos and had a chance to venture out on the street and even stop to take a photo without being accosted by fans.

[neufer]

This was back in the day before Neil did Cosmos and had a chance to venture out on the street and even stop to take a photo without being accosted by fans.

He was still a well placed New Yorker then.

Miracle on 34th Street (Thanksgiving Sunrise ~ 34th Street's eastern end)

<<When demonstrating that he has taken several mental examinations in the past, Kris Kringle answers his own question about who was the Vice President under John Quincy Adams as (New York's own) Daniel D. Tompkins. In fact, it was South Carolina's John C. Calhoun [best known for his intense and original defense of slavery as something positive], while Daniel D. Tompkins had been Vice President under Adams' predecessor, James Monroe. The confusion arose because Adams was the 6th President whereas Tompkins was the 6th Vice President, some Presidents having had a different Vice President in each term, and one of the latter having served under 2 of the former.>>

• Kris Kringle: Who was the first president of the United States?
  
  • • George Washington.
    
    Who was vice president under John Quincy Adams?
    
    • Daniel D. Tompkins.
    
    I'll bet your Mr. Sawyer doesn't know that.

[b][color=#0000FF]Daniel D. Tompkin[/color][/b]

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<<Daniel D. Tompkins (June 21, 1774 – June 11, 1825) was the fourth Governor of New York (1807–1817), and the sixth Vice President of the United States (1817–1825). Tompkins would be the last Vice President to be elected to two terms with the same President until Thomas R. Marshall was reelected Woodrow Wilson's Vice President in 1916. Tompkins' immediate successor, John C. Calhoun served two consecutive terms but under different presidents (John Quincy Adams in 1824 & Andrew Jackson in 1828), and resigned the office before completing his second term.

Tompkins was baptized Daniel Tompkins, but added the middle initial "D." while a student at Columbia College to distinguish himself from another Daniel Tompkins there. There is controversy as to what the middle initial stood for; some have suggested "Decius." On February 20, 1798, Tompkins, a 23-year-old lawyer of the City married 16 year old Hannah Minthorne, daughter of Mangle Minthorne. Their children Hannah and Minthorne were named after their mother, and Hannah and Minthorne streets in Staten Island are named for them.

In 1815 Tompkins established a settlement along the eastern shore of Staten Island that came to be called Tompkinsville. He built a dock along the waterfront in the neighborhood in 1817 and began offering daily steam ferry service between Staten Island and Manhattan. Also in 1817, Governor Tompkins suggested that July 4, 1827, be set as the date on which all slaves in New York state-including those who were born before the Gradual Manumission Act of July 4, 1799, (and who were therefore not eligible for freedom)-should be freed. On July 4, 1827, the African-American community celebrated final emancipation in the state with a long parade through New York City.

While Governor of New York, Tompkins personally borrowed money with his own property as collateral when the New York state legislature would not approve the necessary funds for the War of 1812. After the war, neither the state nor the Federal government reimbursed him so he could repay his loans. His financial problems took a toll on his health, with Tompkins falling into alcoholism, and as Vice President he at times presided over the Senate while intoxicated. He died in Tompkinsville three months after retiring as Vice President and was interred in the Minthorne vault in the west yard of St. Mark's Church in-the-Bowery, New York City. Tompkins had the shortest post-vice presidency of any person who survived the office: 99 days (March 4, 1825 – June 11, 1825).>>

[zbvhs]

This is all very confusing. Aren't we in fact seeing sunset at the Summer Solstice or something close to it? At noon on the solstice the Sun is directly overhead on the Tropic of Cancer and is just visible on the horizon on the side of the Earth opposite the Sun on the Arctic Circle. Twelve hours before and after, the Sun is visible on the horizon at midnight on the side opposite. Hence, the appellation, Land of the Midnight Sun, for the territory above the Arctic circle. On the Antarctic Circle the opposite occurs: the Sun is just visible on the horizon at noon on the side of the Earth toward the Sun. At the Winter Solstice the whole thing is flipped. I vividly remember Mr. Offerdahl's demonstration of all this in Eighth Grade Science many years ago.

[owlice]

This is all very confusing. Aren't we in fact seeing sunset at the Summer Solstice or something close to it?

No. From today's APOD:

This effect makes Manhattan a type of modern Stonehenge, although only aligned to about 30 degrees east of north. Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21, the only two days that the Sun rises and sets due east and west.

[zbvhs]

But, the streets of Manhattan are not aligned east and west, they are offset by 30 degrees. So, the view is that which occurs at the Summer Solstice, i.e., the beginning of summer, which occurred two weeks ago. The Vernal Equinox has nothing to do with the promised view.

[alter-ego]

On June 25, 2003, it was pure happenstance that I realized this sunset scenario. I captured this shot outside of my hotel looking down 35th towards 6th Ave (about 2½ blocks from Niel's location). Being a few weeks early it shows the Sun is still setting slightly northward from the street grid. Not expecting this at all, I was surprised and taken aback by the striking sunset sneaking through New York's skyscrapers. I remember wishing that I could be there for the ideal sunset alignment.

Near-sunset view looking down 35th street, Manhattan.

[owlice]

But, the streets of Manhattan are not aligned east and west, they are offset by 30 degrees. So, the view is that which occurs at the Summer Solstice, i.e., the beginning of summer, which occurred two weeks ago. The Vernal Equinox has nothing to do with the promised view.

Focus on east-west. That's what is being discussed. The equinoxes have everything to do with east-west.

From the APOD:

Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21, the only two days that the Sun rises and sets due east and west.

But they are not perfectly aligned to east and west, so this effect -- the view of the sun from the cross-streets (such as 23rd and 34th), which are the "east-west" streets in Manhattan -- occurs instead in late May and mid July. If the streets were perfectly aligned with east-west, the cross-streets would see this effect on the equinoxes when the sun rises and sets due east and west, as shown in this APOD or

this drawing:

or this video:

Click to play embedded YouTube video.

The equinoxes are good for photographing DC monuments with an east-west orientation, too, as seen here and here, or any monuments with an east-west orientation.

Though offset, Manhattan still gets its east-west (just not due east-west) moment in the sun.

[owlice]

Nice shot, alter-ego!

[FloridaMike]

I was thinking that the farthest north the sun sets is 23.5 degrees. How can this align with a street that has a bearing of 29 degrees north?

[DavidLeodis]

I will be grateful if someone could please inform me of the date when the image was taken (it is copyright 2001) as I do not seem to be able to find out (at least not fairly readily). The information brought up through the "Pictured above" link does not give the date. In the explanation to the APOD it states "Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21" but I'm unsure if the "today's" means July 6 2014 (the APOD date) or the "This coming Saturday" in the explanation.

[neufer]

I was thinking that the farthest north the sun sets is 23.5 degrees. How can this align with a street that has a bearing of 29 degrees north?

The farthest north the sun sets at the equator is 23.5 degrees.

On the Arctic Circle the sun can "set" at 90 degrees.

[FloridaMike]

I was thinking that the farthest north the sun sets is 23.5 degrees. How can this align with a street that has a bearing of 29 degrees north?

The farthest north the sun sets at the equator is 23.5 degrees.

On the Arctic Circle the sun can "set" at 90 degrees.

Thanks, I'm such a plane guy the nuances of spherical geometry sometimes elude me.

[alter-ego]

Nice shot, alter-ego!

Thanks, owl.

[alter-ego]

... This effect makes Manhattan a type of modern Stonehenge, although only aligned to about 30 degrees east of north.

This statement was confusing to me. I thought it referenced the street axis, but it's for the avenues instead. The view to the sunset is ~300° from north, or 30°north of west. The avenues are indeed 30° east of north. I guess street grid "alignment" naturally is wrt north.

[alter-ego]

I will be grateful if someone could please inform me of the date when the image was taken (it is copyright 2001) as I do not seem to be able to find out (at least not fairly readily). The information brought up through the "Pictured above" link does not give the date. In the explanation to the APOD it states "Were Manhattan's road grid perfectly aligned to east and west, today's effect would occur on the Vernal and Autumnal Equinox, March 21 and September 21" but I'm unsure if the "today's" means July 6 2014 (the APOD date) or the "This coming Saturday" in the explanation.

The timing for this shot is a bit squishy. Without a timestamp, and without accurate coordinates for the sun's center (it's too bright!), there is a few-day time window within which the streets are flooded with sunlight. However, with some knowledge of local and horizon terrain (Google), an estimate for the APOD field of view (approximately 38°x50°), and a rough estimate for the sun's center(radial flare rays), I think that time window can be reduced.

It turns out there are two timings that differ by ~5 days: 1) When the technical sunset is aligned with 34th St, and 2) When the full-sun is just above the local horizon and aligned with the street. For case 1), I believe the sunset occurs on Thursday 7/17/14 ± 1day. For case 2), the lowest full-sun, street-center illumination occurs on Saturday, 7/12/14. According to Google, the heading for 34th St is 299.2 ± 0.1°. The time difference between these cases is due to a local horizon having a ½° altitude (formed by a hill between Hoboken and Union City NJ), and that the sun moves at ~40° wrt the horizon.

For Neil's APOD photo, the sun appears slightly to the left of street center, but nominally positioned for full-sun street illumination (case 2 above). The ideal timing for this image would also have been 7/12/01 8:20pm EDT. Judging by the slight leftward decentered sun position, the picture could have easily been taken a couple minutes earlier. This is probably within my position errors. It is also possible the picture was taken the next day just before horizon contact. The sun's azimuth would be ~0.2° to the left. However, I'd bet the shot was planned and that Neil was not a day late.

Without a timestamp, you can see how squishy this timing can be.

[DavidLeodis]

Thanks alter-ego for your informative reply, which is very much appreciated. It must have taken you some time and effort.

[alter-ego]

Thanks alter-ego for your informative reply, which is very much appreciated. It must have taken you some time and effort.

Your welcome David. Yes, it takes some time but good questions aren't always easy to answer.

By the way, the treat of the sun touching the street between skyscrapers is equally, if not more, dramatic for the sunrise. If one stands on 7th ave & 34th St (4 blocks west of Park Ave), the sun will flood 34th St. on Nov 28, 2014 7:05am EST and on Jan 13, 2015 7:25am. These days are optimum but ± 1 day would be just fine. Unlike the sunset, where the visual horizon is the hill in NJ, the visual horizon for the sunrise will be Park Ave which is the highest point on 34th St. Traffic would be silhouetted against the sun!

[DavidLeodis]

Cheers alter-ego. If you are in the area I hope it will be a nice sunset sight on and around those dates. It's a bit far away though from where I am in Yorkshire (in England).

As a non-related note I thought I would mention that some noctilucent clouds were very recently seen at Scarborough (a nice seaside town in Yorkshire) that were even mentioned on the local news being so extremely rarely seen around here. They are getting seen ever further south, but sadly I've not yet seen them. Apologies to APOD discusssers for going off-thread.

[neufer]

By the way, the treat of the sun touching the street between skyscrapers is equally, if not more, dramatic for the sunrise. If one stands on 7th ave & 34th St (4 blocks west of Park Ave), the sun will flood 34th St. on Nov 28, 2014 7:05am EST and on Jan 13, 2015 7:25am. These days are optimum but ± 1 day would be just fine. Unlike the sunset, where the visual horizon is the hill in NJ, the visual horizon for the sunrise will be Park Ave which is the highest point on 34th St. Traffic would be silhouetted against the sun!

[b][color=#0000FF]Snoopy & Woodstock's genuflection to sunrise: Nov 28, 2013[/color][/b]

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The 87th Macy’s Thanksgiving Day Parade in Photos
By Anthony Quintano on November 29, 2013

<<This was a shot I took as the sun began to rise filling the skies with a beautiful vanilla coloring. The best thing was that the Snoopy and Woodstock balloon was facing the sunrise. Since much of the conversation that morning was wondering if the balloons were going to be able to fly, I thought this was a powerful image to start the morning.>>

[alter-ego]

Thanksgiving Day no less, what a coincidence for the Manhattenhenge Sunrise.
I happened to find 2010 picture of exactly the view I suggested (having the Empire State Building on the right side).

Eastward view on 34th St.

Monica Morrison
http://untappedcities.com/2010/01/20/in ... sunrise-2/

Check this very nice time-lapse video of the 2014 sunrise looking down 23 St.

Click to play embedded YouTube video.