What's on your longitude?

[Alps]

I pondered the question, "What if I head due north? Where have I already been on my exact longitude?" So, I traced it out. Here's what I found:
My longitude comes ashore at the Trump Taj Mahal in Atlantic City, crosses the east corner of Great Adventure, and passes through Rutgers just east of New Brunswick. It heads up through Edison and my apartment to downtown Middletown, NY and passes just west of Johnstown on its way to Long Lake in the Adirondacks (NY 28N/30 junction). It crosses into Quebec just east of Fort Covington, NY, between QC 132 and 138, and scrapes Ontario twice, running through Voyageur Provincial Park the second time. After heading west of Lachute, civilization starts disappearing; it crosses the TCH (QC 117) a few kilometers northwest of Ste-Agathe-Nord, and the last place I could drive to on my line of longitude is latitude 51, along the roads around Réserve Faunique Assinica and Lac Mistassini.

[corco]

Longitude is sort of boring for those of us in the west, because of the way South America goes east- latitude is more interesting. That said, the furthest north I can drive is the Fort Smith Highway in the NWT, the largest city on my longitude is Drumheller, Alberta (pop 8,029), and the furthest south I can drive is Mexico Highway 1 in Baja California Sur. I am at the same longitude as the Great Salt Lake, but that's it.

The only towns my longitude hits in the USA, Canada, and Mexio are Gila Bend AZ, Wickenburg AZ, Dugway UT, Deer Lodge, MT, Drumheller AB, and Stettler AB. It does come quite close to Lethbridge.

I-15 crosses my longitude five times- 4 times in Montana and once in Utah. My longitude crosses I-90, I-15, I-86, I-84, I-80, I-40, I-10, and I-8.

My longitude is about 200 feet east of the southern terminus of US 93.

[CNGL-Leudimin]

My longitude goes through Valencia, Spain, the Western suburbs of London, UK, and Scarborough, UK, where the northernmost roads in my longitude are found (Most notably A165).

Some time ago I found the Greenwich meridian (24' East of mine) goes through a town named Berbegal (Spain, near where I live), and therefore I no longer call it the Greenwich meridian, but the Berbegal meridian.

[english si]

Broad brush strokes - a couple of miles corridor (what I can see on the 500m/2000ft zoom level on google):

Arctic Ocean - North Sea - Whitby, western Lincoln suburbs, Rushden, me, Slough, Guildford, Angers, Saintes, Bordeaux, just w of Alicante - Mediterranean - Oran, just e of Winneba - Atlantic Ocean

The Sahara is worse than knowing that there's nothing beyond Mexico/California before the South Pole. I got to the point, thinking it was broken as there was about 500 miles of nothing, except at one point the Algeria/Mali border - just ceaseless beige until south of the Niger, then it was broken up a bit more, with the odd road, or village name, or green area.

CNGL (at 24' West) is about 11 arcminutes east of me (at roughly 35' West) - corresponding to next to no time. We both had solar noon 59 minutes ago. Roughly going through Beverley, Hessle, Sleaford, Luton (yuck), Watford (my birth-place), Goring-by-Sea in the UK, that's about 10 miles west of my longitude at these latitudes.

[NWI_Irish96]

Hudson Bay
Lake Superior
Upper Michigan
Lake Michigan
Grand Rapids, MI
Anderson, IN
Jeffersonville, IN/Louisville, KY
Corner point common to TN/AL/GA
Tuskegee, AL
Panama City, FL
Gulf of Mexico
Caribbean Sea
Trujillo, Honduras
Lake Nicaragua
Western Costa Rica
Pacific Ocean

[US 41]

My longitude goes through Lake Michigan and the north and south poles. 

[mgk920]

I pondered the question, "What if I head due north? Where have I already been on my exact longitude?" So, I traced it out. Here's what I found:
My longitude comes ashore at the Trump Taj Mahal in Atlantic City, crosses the east corner of Great Adventure, and passes through Rutgers just east of New Brunswick. It heads up through Edison and my apartment to downtown Middletown, NY and passes just west of Johnstown on its way to Long Lake in the Adirondacks (NY 28N/30 junction). It crosses into Quebec just east of Fort Covington, NY, between QC 132 and 138, and scrapes Ontario twice, running through Voyageur Provincial Park the second time. After heading west of Lachute, civilization starts disappearing; it crosses the TCH (QC 117) a few kilometers northwest of Ste-Agathe-Nord, and the last place I could drive to on my line of longitude is latitude 51, along the roads around Réserve Faunique Assinica and Lac Mistassini.

Does it run into anything of note in South America?

Mike

[Dr Frankenstein]

I'm aligned with Brooklyn and the Bronx, straight through the Botanical Gardens.

[kphoger]

Going north....  The northern terminus of I-29, six bazillion lakes, the North Pole.

Going south.... Fort Worth (TX), Corpus Christi Bay, South Padre Island, the part of México's Highway 150(D) that crosses over itself in the mountains, the South Pole.

[Brandon]

88 degrees, 08 minutes west.  It passes through Canada's Arctic, Hudson's Bay, Ontario, Lake Superior, Michigan's UP (Keweenaw Peninsula), Wisconsin (Milwaukee), Illinois (including Joliet), skips by Indiana along the Wabash River, Kentucky, Tennessee, Alabama, Mobile Bay, south into Mexico's Yucatan and Quintana Roo, through Belize, Honduras, and El Salvador before entering the Pacific Ocean.

[pianocello]

Mine skirts the western edges of Hudson Bay and Lake Superior, and then crosses the Mississippi River five times and US-61 seven. On the other side of the Gulf of Mexico, it passes straight through Guatemala City. It also goes through the Galapagos archipelago, either through San Salvador or Santa Cruz.

[agentsteel53]

I live not too far east of San Diego, along longitude -116.937 or thereabouts. 

south of me:

most of my town of Lakeside
the town of El Cajon
the western shore of Lower Otay Reservoir
with only a few dozen feet margin of error, the northbound truck lanes of the Otay Mesa border crossing with Mexico
the east half of Tijuana
Puerto Nuevo, a small poblado on the water just off Mexico highway 1D
and that's it, 'til Antarctica

heading north:
the 67 freeway, and a tiny bit of Lakeside
a crossing of 67 where it is a four-lane undivided arterial
a final crossing of 67 where it turns east to head into Ramona
astonishingly little until I note that I am in line (~10 feet margin of error) with the KSDW transmitter tower in the Palomar Mountain area
Hemet, the boundary between Beaumont and Banning, and smack down the middle of Big Bear Lake
avoid Barstow, but hit the logistics base immediately to the east of it
Fort Irwin, and then Death Valley.  Cross into Nevada about a quarter mile west of Daylight Pass Road, which is NV-374
clip the western edges of the Nellis Air Force training range
cross US-50 just east of the NV-376 junction
almost exactly the center of town in Battle Mountain
cross into Idaho about 3 miles east of the triple point with Oregon and Nevada
the next town is Homedale, many miles north.  we head just west of its city hall by about a block
cross into Oregon briefly at a bend in the Snake River. 
back into Idaho, where we miss Weiser to the east, and therefore alas not cross old US-630, the shortest route in the system at 3 miles.
cross into Oregon one last time, and then into Washington only about 3000 feet west of the triple point
cross between Washington and Idaho either 3 or 5 times, depending on the accuracy of my measurement, ending up in Idaho
clip the western outskirts of Genesee ID, a few feet within where I was once not given a traffic ticket (32 in a 25) in 2006 on Cow Creek Road
clip the westernmost 500 feet or so of Lake Coeur d'Alene
cross into British Columbia about 3 miles east of the triple point with BC, ID, and WA
cross into Alberta across the Continental Divide, just south of Mount Dent
cross the Yellowhead Highway - our last major east-west paved road - between Hinton and Edson, AB
cross into Northwest Territories about a mile east of the MacKenzie highway. 



I am astonished that this place is almost exactly due north of where I currently live!

cross the MacKenzie highway for the last time out in the absolute middle of nowhere, along the north shore of Caen Lake
cross into Nunavut in the middle of an unnamed lake, around latitude 66.882
cross back into Northwest Territories around latitude 69.906, on Victoria Island
our last land is a bay on the north shore of Prince Patrick Island around latitude 77.321

[Duke87]

I'm aligned with Brooklyn and the Bronx, straight through the Botanical Gardens.

You are about 2'25" west of me.

Heading south, my longitude passes through the east end of Crooked Island in The Bahamas; a bit west of Les Cayes, Haiti; down through Colombia (Bogota is about 10' west) barely missing Venezuela; Peru; a bit of the western extreme of Brazil; back out to ocean again about 80 km east of Yauca, Peru; back onshore near Ancud, Chile; and out into the Antarctic ocean in a remote area of Tierra del Fugeo.

[vtk]

Combine this with a latitude thread, and anyone who posts in both gives up their exact home location.



This isn't as easy as I'd hoped it would be, as it seems bounding-box display on OSM is currently broken.  Let's see if I can get Google Earth to draw a nice longitude line for me...

North to south: Various large islands of eastern Nunavut; Hudson Bay; wilderness of Ontario; some unnamed roads and then the TCH (GE doesn't identify it with a number) just east of Mattice; Buchannan Lake; more wilderness, apparently; highway 101 and civilization again; TCH again just west of Iron Bridge; Lake Huron, including that pass of water just east of Cockburn Island; Near-miss of some islands just off Alpena, MI; come ashore and cross M-25 in a light residential area northeast of Caseville; cross I-69 just east of the Wilder Rd interchange near Lapeer; cross I-75, I-96, I-94, I-75 again in Detroit suburbs; embarking across Lake Erie at Estral Beach and coming ashore just east of Reno Beach, OH; cross the Turnpike a few miles east of Elmore; cross US in its eastern interchange with US 23, and US 23 a few miles south; cross Scioto River a bit upstream from Green Camp; cross I-70 just about at its closest point to my home; cross US 40 / National Road through the eastern arches of a 40s-vintage concrete arch bridge; cross I-71 not particularly near anything; Deer Creek Lake and associated State Park; cross US 50 just east of Bainbridge; a cemetery on an illogically-sharp bend in OH 772; Ohio River between Garrison and Vanceburg; approximate a jaggy part of the Carter—Lewis county line in Kentucky; I-64 west of Olive Hill; mostly farmland across the western tip of Virginia; I-81 near Morristown, TN; the east end of Douglas Lake; I-40 near Newport; Great Smoky Mts Nat'l Park, passing near Mt Guyot; Extreme NE Georgia, estreme W South Carolina, then into Georgia again; I-85 near Carnesville; the center of Carnesville; I-20 just W of Greensboro; Oconee Lake and Sinclair Lake a few times each; I-16 in the GA-112 interchange; I-75 a few miles north of the Florida—Georgia border; I-10 a few miles east of the Lee rest area; into the Gulf of Mexico at Horseshoe Cove; miss Loggerhead Key by several miles; Cuba, crossing a few miles east of an invisible town Google calls Puerto Escondido, the western Caribbean Sea; nicking Honduras and Nicaragua at the mouth of the Coco river, then grazing Nicaragua again; Costa Rica; Gulf of Dulce and into the Pacific; missing South America by a hundred miles or so; Antarctica, including the Ellsworth Mountains.

[Dougtone]

I live in the Town of Glenville, New York, slightly east of the Village of Scotia and the City of Schenectady.

Things that are directly due south of me include the tip of Breezy Point, which many of you may be familiar with due to the destruction that was caused by Sandy.  Pass through parts of Harlem, the eastern part of Roosevelt Island, just east of the George Washington Bridge.  Cross the Hudson River a few times and even go through ritzy Alpine, NJ.  Pass just east of downtown Beacon, NY and through the famed Bowtie interchange in Poughkeepsie, Franklin D. Roosevelt's backyard at his estate in Hyde Park and the Kingston-Rhinecliff Bridge.  After passing just east of downtown Saugerties, the next place of note is Schenectady.

Going north, I go through some scenic country in the Adirondacks.  Things of note include the eastern arm of the Great Sacandaga Lake, Wevertown, just west of Lake Tear of the Clouds, just east of downtown Lake Placid and Whiteface Mountain.  I cross the border into Canada at Franklin Centre, which is where NY 189 becomes QC 209.  Cross the St. Lawrence in Melocheville, Ile Perrot, so not far from Montreal.  Last thing of note that I noticed was that the longitude line passed east of St. Jerome, Quebec.

This would be a fun exercise to look at latitude as well, lots of interesting things due west or due east of me.

[vtk]

Actually, what's on your latitude isn't necessarily due east or west of you. For that, you want the great circle which reaches maximum latitude as it passes through your home.

I could probably write a web service to create kml files of great circles with specified origin and direction. This could demonstrate the fact that if A is due east of B, B probably isn't due west of A.

[agentsteel53]

Combine this with a latitude thread, and anyone who posts in both gives up their exact home location.

eh, people generally know where I live. 

This isn't as easy as I'd hoped it would be, as it seems bounding-box display on OSM is currently broken.  Let's see if I can get Google Earth to draw a nice longitude line for me...

I had wondered what everyone's technique was.  Mine was to use google maps's "what's here" function, in the right-click menu.  that will load the latitude and longitude of whatever is clicked on.  I started with my house, and made note of the longitude. 

then I scrolled approximately north and when I ran into interesting things, I clicked "what's here", and replaced the reported longitude with the desired one, which yielded an arrow exactly on my longitude line, from which I could report the context.

[agentsteel53]

Actually, what's on your latitude isn't necessarily due east or west of you. For that, you want the great circle which reaches maximum latitude as it passes through your home.

I have never heard this interpretation before!  so your definition of "due east" is to follow a route which is the precise circumference of the earth, and crosses the equator twice, going through your antipodal point as well?

one result of this interpretation is that if you live at the north pole, the south pole is due east of you - and you may choose any pair of opposing longitude lines to get there.

I do not believe this to be the correct mathematical definition, but it does yield an interesting locus of points.

[vtk]

Actually, what's on your latitude isn't necessarily due east or west of you. For that, you want the great circle which reaches maximum latitude as it passes through your home.

I have never heard this interpretation before!  so your definition of "due east" is to follow a route which is the precise circumference of the earth, and crosses the equator twice, going through your antipodal point as well?

one result of this interpretation is that if you live at the north pole, the south pole is due east of you - and you may choose any pair of opposing longitude lines to get there.

I do not believe this to be the correct mathematical definition, but it does yield an interesting locus of points.

Yes, your summary of my interpretation is correct. Whether or not it is correct depends on whether you're thinking about traveling constantly due east, or looking due east from a stationary point.  But I'm pretty sure Muslims at the same latitude as Mecca don't face due east or west when they prey, but rather in the great-circle direction.

[agentsteel53]

looking due east from a stationary point.

I had not thought of it that way.  you are absolutely correct.

But I'm pretty sure Muslims at the same latitude as Mecca don't face due east or west when they prey, but rather in the great-circle direction.

I looked it up, and there is a well-specified direction for Muslim prayer at Amundsen-Scott polar station.

http://www.islamicfinder.org/prayerDetail.php?country=antarctica&city=South_Pole_-_Amundsen-Scott_Station_South_Pole&state=00&id=6&month=&year=&email=&home=2013-5-10&lang=&aversion=&athan=

that is defined to be 90 degrees latitude south, but given that a) the station is not located at the true pole, or even the ceremonial pole, and b) there is a well-defined vector for "direction to Mecca", the implication is that it is in fact 89.xxxS, xx.xxxE/W and those values are very well known.

given that the station shifts relative to the true pole, and any small change is magnified into a large difference in the "looking east" vector, I'll bet they have to adjust the direction to Mecca pretty frequently.

[vtk]

Actually I just found out there are two methods for determining direction to Mecca: great circle, or constant-compass/Mercator/loxodrome.  Apparently there isn't universal agreement on which is right.

Regarding a mobile station near the South Pole, the great circle direction to Mecca would indeed swing wildly relative to local north, but would be quite stable relative to the orientation of the south-polar UTM zone.  The shortest loxodrome, on the other hand, would always point nearly north, more closely constrained to due north as the station approaches the pole – the point at which north becomes nonspecific and the local direction of every nonmeridian loxodrome is undefined.

My great circle generator should be ready soon, by the way, featuring start-and-direction mode. Through-two-points mode will come at a later date.

[Duke87]

Actually, what's on your latitude isn't necessarily due east or west of you. For that, you want the great circle which reaches maximum latitude as it passes through your home.

I have never heard this interpretation before!  so your definition of "due east" is to follow a route which is the precise circumference of the earth, and crosses the equator twice, going through your antipodal point as well?

one result of this interpretation is that if you live at the north pole, the south pole is due east of you - and you may choose any pair of opposing longitude lines to get there.

I do not believe this to be the correct mathematical definition, but it does yield an interesting locus of points.

This methodology produces several weird consequences.
- two people heading due east from any two points on Earth will at some point have their paths cross
- as you head "east" your bearing gradually becomes further away from perpendicular to north-south

I would never have even thought of it, parallel latitude avoids these problems and is more real-world meaningful given how the earth rotates.

As for direction to Mecca, or any other point on Earth, I would determine that by measuring the distance along your latitude to Mecca's longitude, measuring the distance from there down that longitude to Mecca, and determining what angle makes the hypotenuse of that (admittedly distorted) right triangle.

[NE2]

The problem with the great circle definition is that it's not transitive. If point A is east of point B, point B is not west of point A (unless they're exactly opposite). I think you would have to define an "east pole" and "west pole" on the equator to make transitive great circle definitions.

[vtk]

I just dislike lat-lon or loxodrome or similar methods because they place too much importance on meridians and parallels (which aren't natural features) and, in some cases, expose people's Mercator-like flat world view.

Side note: everyone should own at least one globe.

[english si]

I just dislike lat-lon or loxodrome or similar methods because they place too much importance on meridians and parallels (which aren't natural features)

Great circles certainly aren't natural features...

Meridians at least have natural phenomena all the way along them (noon at the same time).

Side note: everyone should own at least one globe.

Well yes, but you would still use lat and lon to describe position - if you note, the coordinates are angles and thus how you work with spherical objects.

And with axes you would have the axis of rotation as a blatantly obvious one (even if not trying to cross oceans and working out longitude by a clock and local noon...) and there isn't an obvious second axis (west and east poles), so the angle from the midpoint between north and south poles is a naturally obvious second measure.

And west and east as concepts exist because it bisects the N-S axis. W and E have to be a constant angle in relation to the measurable N-S axis and not dependent on where you started (partially as it then becomes hard to work out where west is as local west is a different direction to west-where-you-started), otherwise it's totally useless as a concept!