GPS vs Maps

[spokewrench]

on a related note... it really surprises me how many people don't know which direction is which. sometimes when giving someone (simple) directions, i'll say "go north x blocks then turn left."

... "which way is north?"

given that most american cities have large areas of roughly n-s-e-w street grids, and the sun is somewhat reliable in it's path to the sky, and the pacific ocean is still most often west of the north american continent, this seems an odd thing to not internalize.

When I lived half a mile from the Pacific, we didn't call streets north because they ran at 315 degrees, parallel to the coast. Where I live now, Main Street runs at 48 degrees east, but they call it north because the town sprang up along a rail line that ran in that direction, and they called it north. I picture streets in terms of geographic north but give directions in lefts and rights. The person asking probably doesn't know the local compass. When the sun is high, its direction may not be clear. When it's low, its direction can vary a lot during the year. It may not be visible at all.

My town is askew because of the railroad, but farther west, it caused NSEW grids of roads. Railroads made farming feasible. With no existing roads, a NSEW grid was simplest for surveyors preparing the land for sale or grant.

There's an advantage dating back at least as far as ancient Egypt: God's calendar. Everywhere on earth, sunrise and sunset are 180 degrees apart on two days of the year: spring and autumn equinox. That's 90 and 270 degrees, everywhere in the world. Peoples who roam tell time in moons. People with permanent structures can see the approximate time from an equinox by viewing a sunrise or sunset in relation to an east-west wall or street.

Julius Caesar overthrew the system in the Roman Empire in BC 45 by imposing January 1 as New Year's Day. That was to streamline tax collection. Rome soon conquered Britain, but it wasn't until 1752 that George II, a German, forced Britain and America to start the new year on January 1.

 

[mschwett]

When I lived half a mile from the Pacific, we didn't call streets north because they ran at 315 degrees, parallel to the coast. Where I live now, Main Street runs at 48 degrees east, but they call it north because the town sprang up along a rail line that ran in that direction, and they called it north. I picture streets in terms of geographic north but give directions in lefts and rights. The person asking probably doesn't know the local compass. When the sun is high, its direction may not be clear. When it's low, its direction can vary a lot during the year. It may not be visible at all.

My town is askew because of the railroad, but farther west, it caused NSEW grids of roads. Railroads made farming feasible. With no existing roads, a NSEW grid was simplest for surveyors preparing the land for sale or grant.

There's an advantage dating back at least as far as ancient Egypt: God's calendar. Everywhere on earth, sunrise and sunset are 180 degrees apart on two days of the year: spring and autumn equinox. That's 90 and 270 degrees, everywhere in the world. Peoples who roam tell time in moons. People with permanent structures can see the approximate time from an equinox by viewing a sunrise or sunset in relation to an east-west wall or street.

Julius Caesar overthrew the system in the Roman Empire in BC 45 by imposing January 1 as New Year's Day. That was to streamline tax collection. Rome soon conquered Britain, but it wasn't until 1752 that George II, a German, forced Britain and America to start the new year on January 1.

right, there are definitely localized areas where streets are close enough to 45 degrees to limit the usefulness of the cardinal points. a good chunk of our street grid is turned 44 degrees (following the original spanish road from harbor to mission), and everyone in the know knows which was is "north" instead of "west" but lots of people aren't in the know

 

[spokewrench]

About 1960 I bought a Suunto compass similar to the legendary M-34. By bike, skis, or snowshoes, I could sight a mountain, for example, identify it on a map, and use it to fix my position as I progressed in unfamiliar territory. I assumed it was painted with radium, which would continue to emit gamma rays no matter how many years I kept it in my pocket. In the 21st Century, I noticed that the markings were faint by day and invisible at night. It must have been worn-out tritium paint.

About that time I spotted a Vion Mini Morin 2000 Hockey Puck at a flea market. Yachtsmen use them to take bearings when an error can mean hitting a submerged rock. I gladly paid $3 for this $250 item. There was a bubble in the damping fluid. If the bubble got under the disk, the disk would tilt. I drilled a tiny hole, found that the fluid was mineral spirits, filled the space with a hypodermic needle, and sealed the hole with epoxy.

The compass could be read to 1/2 degree. Going along a straight road, it would reveal small deviations in the magnetic field. From a vantage point, I could get an azimuth to something unusual, find it on a map, and use the compass and map to pedal there.

The bubble reappeared. I've refilled the compass and tried different sealants, but the bubble reappears. What will plug a hole against mineral spirits?

 

[Jeremy McCreary]

Denver was built on 2 grids, the original parallel to the NE-trending South Platte River front. The surrounding N- and E-trending grid came later.

Lived there 20 years. I'm pretty good with directions, but to the end, navigating the grid transition zone felt like sailing Colorado's version of the Bermuda Triangle.

 

[spokewrench]

right, there are definitely localized areas where streets are close enough to 45 degrees to limit the usefulness of the cardinal points. a good chunk of our street grid is turned 44 degrees (following the original spanish road from harbor to mission), and everyone in the know knows which was is "north" instead of "west" but lots of people aren't in the know

In Seattle, sunrise varies 71 degrees, from 54 on June 23 to 125 on December 23. Similarly, sunset varies 72 degrees during the year. That's if you can see the sun. I may have spent a month there. If I ever saw the sun, I don't remember it. Left and right are simpler. Being ambidextrous, I find it helpful to refer to the mirror on the my handlebar.

 

[spokewrench]

Denver was built on 2 grids, the original parallel to the NE-trending South Platte River front. The surrounding N- and E-trending grid came later.

Lived there 20 years. I'm pretty good with directions, but to the end, navigating the grid transition zone felt like sailing Colorado's version of the Bermuda Triangle.

Until I was 9 I lived in Worcester, MA. In my couple of square miles, roads were NSEW. That's because the original road ran along a NS ridge. Home builders wanted frontage for quick transportation. They wanted 90 degree corners, so side streets were EW.

Most of the city wasn't like that. Whites began settling in 1673 because they loved the lakes and steep hills. Neighborhoods had their streets aligned to fit the spaces.

Where I live now, mill owners dominated the town council. In the 1980s they closed off my street to build a warehouse. They soon went out of business, but the damage was done. People come looking for addresses that are in fact on the other side of the mill buildings. I say, "Go 100 yards and turn right. Then turn right at your first stop sign. In 200 yards there will be a place to bear right. Bear right. Bear right again. The street sign will tell you it's the other end of this street.

That's not a time to talk about compass directions.

 

[Brian-s]

My pet peeve is people who orient their maps any way but having North at the top.

My pet peeve is people who don't draw declination lines showing true north

 

[Stefan Mikes]

There were times when teeth were pulled with pincers without anaesthesia

I wouldn't stand a chance without a Wahoo while cycling in London. If I missed a correct turn then the detour meant long miles.