Manhattanhenge and Historical Hengetide
Posted July 8th, 2012 at 05:06 PM by Tobias Binch
Manhattanhenge and Historical Hengetide If it's too hot, I'll be in a pub, but if it's not near 33 (and it's been around and above that temperature for close to a week now) on 12 July, I'll attend a Manhattanhenge sighting.
It's not very popular, well-known, or even with a long folk tradition, but the architectural peculiarities of Manhattan's design make it possible for the setting sun to descend down the streets of manhattan without any obstructing buildings blocking the fully visible disc of the sun. On most days of the year the angle of descent and other factors don't properly mesh -- almost, but not quite, so all you get is a bit of the sun shining down, but around 21 days after the Summer Solstice (and circa 21 days before the Solstice too), an illusion is created so that the reddish-golden sun is perfectly guided to its diurnal slumber by the skyscrapers on each side of it.
A local scientist, Neil deGrasse Tyson, named the effect Manhattanhenge. The ninety degree angles of the streets across all of Manhattan is something you won't find so consistently on every street in London or most old-world cities. On some, yes, but not 90 degrees on every street. The solar effect wasn't part of the 1811 planning of Manhattan's streets. It's a modern aesthetic reimagining and repurposing, one that sometimes catches my attention.
Personally I think it has more of a conceptual connexion with with Egypt and the pylons, with the sun in the center, and obelisks (all the other skyscrapers would be obelisks) than with stonehenge, but that is another topic. 21 days before and after the Summer Solstice and 21 days before and after the Winter Solstice the Manhattanhenge effects occur. For the Summer Solstice, the effects are best viewed when looking for the setting sun and for the Winter Solstice, the effects are best viewed when looking for the rising sun.
I hope this won't be taken as mocking Heathenism/Paganism, but when I was thinking about this manhattanhenge effect a long time ago, I realised that a calendar system could be created around the effect in a way not disimilar to the Anglo-Saxon calendar as described by Bede (which I believe to be similar in concept to the Celtic Calendars based on bits and pieces that survive). I even pondered if such a calendar could be sold, possibly through Llewelyn publication or directly to bookstores, a calendar for every city where a similar effect occurs. If the pictures for each month were of the right quality, it would sell to Rizzoli Bookstores along with most independent stores, the few left.
The rest of this is calendrics, with a wee bit of math referenced. I'm doing this to remind myself of it. If anyone happens to be reading this about calendars (slightly surprising), the Anglo-Saxon calendar reconstruction is based on Bede's De Temporum Ratione. In particular, Chapter 15 and the part that I find most people don't mention when attempting to describe the Anglo-Saxon calendar, this part: ... tunc tres menses simul Lida nomine vocarentur .... meaning a third month also called Lida (or Litha as it is spelled in later texts, with assumes that the d is meant to be a ð, or eth). That third month is an automatic adjuster, which means to me that the metonic cycle could easily be used (though I won't explain that here).
I have seen some reproductions of calendars and mechanisms to measure the skies and I have read other sources besides De Temporum Ratione, but I'm doing this mostly extemporaneously, if you'll pardon the pun, so I'm not bothering to look up or remember names and sources or bothering to reproduce a chart that I would draw in 30 seconds with paper and pencil.
It's not described by Bede in this way, but the Anglo-Saxon calendar sections off the solstice by a cutting away a period of 49 days before each solstice and 49 days after each solstice. The new moon that first falls into that pre-solstice period is the start of the special month, called by the Saxons Pre-Lida for the Summer Solstice and Pre-Giuli for the Winter Solstice. The next month is then called by them Post-Lida and Post-Giuli. Actually according to Bede there is no Pre and Post (or aerra or other prefixes). It's just the same month name again. If the next new moon is STILL within that 49 day period after the solstice, it is again called Lida, which is what Bede means when he talks about a third month named Lida. It's sometimes called an intercalculary month, but I get the sense it was closer to a time set aside, conceptually like Advent Time or even Lenten Time, a time period that contained something. So this was Hengetime, or Hengetide, to use an older word ending.
The Anglo-Saxons gave more importance to the Summer Solstice than the Winter Solstice, so things like the extra month were focused around that solstice. The Celts seemed to give at least equal if not more importance in some ways to the Winter Solstice. The 49 day markers are based on mathematics of a 365/366 day year. Many modern pagans fix dates to what they call the quarter days onto the Gregorian calendar. This 49 day period happens to hover right around these days.
For example, it is now the year 2012 and the Summer Solstice occurred on 20 June (UTC times and dates for everything). 49 days prior to this is 1 May, which happens to be the day most often picked for Beltane (Calan Mai for the Welsh and other names in other languages). This is the start of Summer in those old traditions, with the next new moon indicating the start of the first month of Summer.
Lammas/Loaf-Mass and the other holy days similarly get mapped out. Going by the 49 day period, some of the days are a week later than what is now the more common date. Lammas, for example, would fall on the 8th of August in 2012. But I believe that modern Lammas as 1 August exists on that date because of an attempt to create symmetry with 1 May. In earlier times when the Church tried to cover up Pagan festivals with their own, there was a field blessing day that was on the first or the sixth of August. I have been told (but not seen the text myself) that the Sacramentary of Pope Gregory I specifies the sixth, so there seems to be some variance about the date trying to be covered up.
Halloween as the beginning of the new year in some Celtic calendar traditions seems to fit well with a date 49 days before the Winter Solstice. In 2012, 49 days before the 21 December Solstice is 2 November. They are called quarter days, these Pagan/Heathen holy days, but they are not a quarter of the time at all, those modern dates. At least not in the counting of the modern calendar. This was a problem I sloshed around in my head once upon a time instead of doing proper work
But if the 49 day periods (plus the solstice day itself) is added up, you get 99 (sometimes 100 depending on rounding off, the issue of whether a day starts in the evening prior to the day, and one or two other concerns) days. Why the insistence upon 49 days? Did I pull it out of the air? That number in itself isn't as important as the days left over - 266 days. If you go by the moon, a lunar month on average is 29.5 days (averaging one month of 29 and one day of 30 is common in more than a couple of calendar systems to get this average). When you multiple 9 lunar months, you get 265 (or 265.5 to be exact, which might get rounded up or down) which is what was left over after subtracting that 99 day period. I doubt that the name quarter days was meant as some magnificent clue, but the Anglo-Saxons and Celts had their calendar before the Gregorian or Julian, so the Gregorian calendar can't be relied upon. My reckoning has a 9 month/266 day (three-quarter part) section separated from each solstice plus 49 days on each side, which then becomes a quarter section by the definition that if one section is three-quarters, the other section must be one quarter: so the 'quarter' days at each end of the 99 days mark off that special quarter section of the year.
This seemed to fit mathematically so that's why I used it. I won't go into details here, but using a fort'night as the unit to display the year and overlaying the metonic cycle numbers onto the various days in a consistent pattern within each fort'night produces a chart that makes predicting the months very easy and gives a visually pleasing pattern. I programmed and printed out such a chart. It seems that some Scandanavian calendar sticks and even English medieval calendars do something not too much different.
As for how to know when it is 49 days before or after a solstice, I have gone on the assumption that the standing stones, ones like at Avebury, would be used. 49 days before the solstice, the sun would always be at a certain slant, a certain height at its highest point that would cast a certain shadow. Equally likely, at night certain stars would always be in a certain position on a certain day (though because of precession, they would be off by a degree every 72 years, but this would be enough for the lifetime of any one person in charge of figuring out months - and calendars of these times weren't supposed to be perfect for all of eternity, even the Julian calendar was always off by about a day every 128 years). Since there's no written proof, I can't be sure, but it's what I'd do: use either the rising of a certain star (which is what they egyptians did) or use the sun.
Not really much mathematics at all. And it is a guess about how the 49 day markers are determined, but it does all fit. That 99 day period would have automatically ensured for the Anglo-Saxons that they had a leap year every so often. The Coligny calendar in Gaul suggests to me something similar, though it uses multiple lunar cycles.
As for my calendar for Manhattan, I based it all on the same idea.
The manhattanhenge effect takes place approximately 21 days after the Summer solstice (the date varies, from 11 july to 13 july). I found that to be just a day or so too long, so I assumed a 20 day period on either side. Call it an inner henge or ditch if you will, or call it a waiting time until the effect, a period outside of everything or just solstice time or hengetide. But with those two 20 day periods and the solstice itself, you get 41 days. When you subtract this from 365, you get 324, which happens to be 11 lunar months (11 multiplied by 29.5 produces 324.5).
Discussing my theory over drinks with someone, we thought of naming each month in our Manhattan calendar after a different neighbourhood, or even getting a corporate sponsor. Mr Trump would surely jump at the chance of renaming either of the two Caesarian months of July and August as something like Trumpuary. I had some other scheme of splitting the year in half, like the celtic calendar, with a winter and summer half and a borough name in each half, so a Winter Brooklyn and a Summer Brooklyn and Manhattan would get the month before and after each solstice.
It's not very popular, well-known, or even with a long folk tradition, but the architectural peculiarities of Manhattan's design make it possible for the setting sun to descend down the streets of manhattan without any obstructing buildings blocking the fully visible disc of the sun. On most days of the year the angle of descent and other factors don't properly mesh -- almost, but not quite, so all you get is a bit of the sun shining down, but around 21 days after the Summer Solstice (and circa 21 days before the Solstice too), an illusion is created so that the reddish-golden sun is perfectly guided to its diurnal slumber by the skyscrapers on each side of it.
A local scientist, Neil deGrasse Tyson, named the effect Manhattanhenge. The ninety degree angles of the streets across all of Manhattan is something you won't find so consistently on every street in London or most old-world cities. On some, yes, but not 90 degrees on every street. The solar effect wasn't part of the 1811 planning of Manhattan's streets. It's a modern aesthetic reimagining and repurposing, one that sometimes catches my attention.
Personally I think it has more of a conceptual connexion with with Egypt and the pylons, with the sun in the center, and obelisks (all the other skyscrapers would be obelisks) than with stonehenge, but that is another topic. 21 days before and after the Summer Solstice and 21 days before and after the Winter Solstice the Manhattanhenge effects occur. For the Summer Solstice, the effects are best viewed when looking for the setting sun and for the Winter Solstice, the effects are best viewed when looking for the rising sun.
I hope this won't be taken as mocking Heathenism/Paganism, but when I was thinking about this manhattanhenge effect a long time ago, I realised that a calendar system could be created around the effect in a way not disimilar to the Anglo-Saxon calendar as described by Bede (which I believe to be similar in concept to the Celtic Calendars based on bits and pieces that survive). I even pondered if such a calendar could be sold, possibly through Llewelyn publication or directly to bookstores, a calendar for every city where a similar effect occurs. If the pictures for each month were of the right quality, it would sell to Rizzoli Bookstores along with most independent stores, the few left.
The rest of this is calendrics, with a wee bit of math referenced. I'm doing this to remind myself of it. If anyone happens to be reading this about calendars (slightly surprising), the Anglo-Saxon calendar reconstruction is based on Bede's De Temporum Ratione. In particular, Chapter 15 and the part that I find most people don't mention when attempting to describe the Anglo-Saxon calendar, this part: ... tunc tres menses simul Lida nomine vocarentur .... meaning a third month also called Lida (or Litha as it is spelled in later texts, with assumes that the d is meant to be a ð, or eth). That third month is an automatic adjuster, which means to me that the metonic cycle could easily be used (though I won't explain that here).
I have seen some reproductions of calendars and mechanisms to measure the skies and I have read other sources besides De Temporum Ratione, but I'm doing this mostly extemporaneously, if you'll pardon the pun, so I'm not bothering to look up or remember names and sources or bothering to reproduce a chart that I would draw in 30 seconds with paper and pencil.
It's not described by Bede in this way, but the Anglo-Saxon calendar sections off the solstice by a cutting away a period of 49 days before each solstice and 49 days after each solstice. The new moon that first falls into that pre-solstice period is the start of the special month, called by the Saxons Pre-Lida for the Summer Solstice and Pre-Giuli for the Winter Solstice. The next month is then called by them Post-Lida and Post-Giuli. Actually according to Bede there is no Pre and Post (or aerra or other prefixes). It's just the same month name again. If the next new moon is STILL within that 49 day period after the solstice, it is again called Lida, which is what Bede means when he talks about a third month named Lida. It's sometimes called an intercalculary month, but I get the sense it was closer to a time set aside, conceptually like Advent Time or even Lenten Time, a time period that contained something. So this was Hengetime, or Hengetide, to use an older word ending.
The Anglo-Saxons gave more importance to the Summer Solstice than the Winter Solstice, so things like the extra month were focused around that solstice. The Celts seemed to give at least equal if not more importance in some ways to the Winter Solstice. The 49 day markers are based on mathematics of a 365/366 day year. Many modern pagans fix dates to what they call the quarter days onto the Gregorian calendar. This 49 day period happens to hover right around these days.
For example, it is now the year 2012 and the Summer Solstice occurred on 20 June (UTC times and dates for everything). 49 days prior to this is 1 May, which happens to be the day most often picked for Beltane (Calan Mai for the Welsh and other names in other languages). This is the start of Summer in those old traditions, with the next new moon indicating the start of the first month of Summer.
Lammas/Loaf-Mass and the other holy days similarly get mapped out. Going by the 49 day period, some of the days are a week later than what is now the more common date. Lammas, for example, would fall on the 8th of August in 2012. But I believe that modern Lammas as 1 August exists on that date because of an attempt to create symmetry with 1 May. In earlier times when the Church tried to cover up Pagan festivals with their own, there was a field blessing day that was on the first or the sixth of August. I have been told (but not seen the text myself) that the Sacramentary of Pope Gregory I specifies the sixth, so there seems to be some variance about the date trying to be covered up.
Halloween as the beginning of the new year in some Celtic calendar traditions seems to fit well with a date 49 days before the Winter Solstice. In 2012, 49 days before the 21 December Solstice is 2 November. They are called quarter days, these Pagan/Heathen holy days, but they are not a quarter of the time at all, those modern dates. At least not in the counting of the modern calendar. This was a problem I sloshed around in my head once upon a time instead of doing proper work
But if the 49 day periods (plus the solstice day itself) is added up, you get 99 (sometimes 100 depending on rounding off, the issue of whether a day starts in the evening prior to the day, and one or two other concerns) days. Why the insistence upon 49 days? Did I pull it out of the air? That number in itself isn't as important as the days left over - 266 days. If you go by the moon, a lunar month on average is 29.5 days (averaging one month of 29 and one day of 30 is common in more than a couple of calendar systems to get this average). When you multiple 9 lunar months, you get 265 (or 265.5 to be exact, which might get rounded up or down) which is what was left over after subtracting that 99 day period. I doubt that the name quarter days was meant as some magnificent clue, but the Anglo-Saxons and Celts had their calendar before the Gregorian or Julian, so the Gregorian calendar can't be relied upon. My reckoning has a 9 month/266 day (three-quarter part) section separated from each solstice plus 49 days on each side, which then becomes a quarter section by the definition that if one section is three-quarters, the other section must be one quarter: so the 'quarter' days at each end of the 99 days mark off that special quarter section of the year.
This seemed to fit mathematically so that's why I used it. I won't go into details here, but using a fort'night as the unit to display the year and overlaying the metonic cycle numbers onto the various days in a consistent pattern within each fort'night produces a chart that makes predicting the months very easy and gives a visually pleasing pattern. I programmed and printed out such a chart. It seems that some Scandanavian calendar sticks and even English medieval calendars do something not too much different.
As for how to know when it is 49 days before or after a solstice, I have gone on the assumption that the standing stones, ones like at Avebury, would be used. 49 days before the solstice, the sun would always be at a certain slant, a certain height at its highest point that would cast a certain shadow. Equally likely, at night certain stars would always be in a certain position on a certain day (though because of precession, they would be off by a degree every 72 years, but this would be enough for the lifetime of any one person in charge of figuring out months - and calendars of these times weren't supposed to be perfect for all of eternity, even the Julian calendar was always off by about a day every 128 years). Since there's no written proof, I can't be sure, but it's what I'd do: use either the rising of a certain star (which is what they egyptians did) or use the sun.
Not really much mathematics at all. And it is a guess about how the 49 day markers are determined, but it does all fit. That 99 day period would have automatically ensured for the Anglo-Saxons that they had a leap year every so often. The Coligny calendar in Gaul suggests to me something similar, though it uses multiple lunar cycles.
As for my calendar for Manhattan, I based it all on the same idea.
The manhattanhenge effect takes place approximately 21 days after the Summer solstice (the date varies, from 11 july to 13 july). I found that to be just a day or so too long, so I assumed a 20 day period on either side. Call it an inner henge or ditch if you will, or call it a waiting time until the effect, a period outside of everything or just solstice time or hengetide. But with those two 20 day periods and the solstice itself, you get 41 days. When you subtract this from 365, you get 324, which happens to be 11 lunar months (11 multiplied by 29.5 produces 324.5).
Discussing my theory over drinks with someone, we thought of naming each month in our Manhattan calendar after a different neighbourhood, or even getting a corporate sponsor. Mr Trump would surely jump at the chance of renaming either of the two Caesarian months of July and August as something like Trumpuary. I had some other scheme of splitting the year in half, like the celtic calendar, with a winter and summer half and a borough name in each half, so a Winter Brooklyn and a Summer Brooklyn and Manhattan would get the month before and after each solstice.
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