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Maps that show time instead of space

spacetime-maps.vercel.app

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Re: Maps that show time instead of space

#31

Post by rompic »

avidiax wrote: post #28
danbruc wrote: post #6

See also isochron map [1]. [1] https://en.wikipedia.org/wiki/Isochrone_map

I prefer the typical isochron presentation over the warping. It's unfortunately hard to find free, public isochron maps, though. Some examples I've found: https://www.targomo.com/developers/apis/isochrone/ https://direkt.bahn.guru/?origin=8503000 https://www.chronotrains.com/en

There is also https://www.mapnificent.net/ For public transport

Re: Maps that show time instead of space

#33

Post by perihelions »

adamcanady wrote: post #2

This is neat but the map by public transport time is probably non-euclidean because subways are like wormholes.

Right, the travel-time metric is not compatible with a Euclidean R² metric. You can imagine three subway stations in a triangle loop, such that it's a shorter trip to do a full loop on the subway then to walk to a point in the interior.

There's no way to continuously deform a map so that it represents travel times as distance in a plane.

Re: Maps that show time instead of space

#34

Post by echoangle »

ars wrote: post #24
adamcanady wrote: post #2

This is neat but the map by public transport time is probably non-euclidean because subways are like wormholes.

Not really - you have to wait for the subway, it also takes a finite time to travel, and it frequently stops. It can avoid traffic, but the actual MPH can be slower than a car when you include both those things.

Isn’t the point that you have a way to get to a point far away faster than you can get to a point in between? The worm hole thing ist because you can only exit at discrete points so it pulls a single point far away, and it’s sorrounding, closer to the starting point. That’s probably hard to map to a 2D map because there would be some overlap between the different „islands“ starting from subway stations

Re: Maps that show time instead of space

#36

Post by vvolhejn »

markerz wrote: post #9

Interesting twist on what other people have done, namely show a heat-map of where you can go using public transit + walking within 5 min, 15 min, 30 min. time2reach https://map.henryn.ca/San%20Francisco NYC Subwaysheds https://news.ycombinator.com/item?id=36240264

Yes! This is a less practical but more funky version of isochrone maps.

Re: Maps that show time instead of space

#37

Post by vvolhejn »

adamcanady wrote: post #2

This is neat but the map by public transport time is probably non-euclidean because subways are like wormholes.

Oh yes, unfortunately, you can't do this perfectly. There are some graphs that cannot be embedded in Euclidean space in any number of dimensions, e.g. a 4-cycle with distance measured by path length. It's a good-enough approximation for visualization purposes, though.

Re: Maps that show time instead of space

#38

Post by vvolhejn »

puzzledobserver wrote: post #17

This sounds conceptually difficult: Wouldn't the presence of one-way streets or airport security checkpoints, for example, mean that the travel time from A to B might not be the same as the travel time from B to A? How can a map then be drawn?

Indeed, you can't do this perfectly – it's an approximation. I just use one of the two directions as the travel time because if I wanted to symmetrize I'd have to call the Google Maps API twice . Asymmetry aside, it's also not possible to perfectly embed metrics in 2D Euclidean space, or any-dimensional Euclidean space for that matter (see other comment)

Re: Maps that show time instead of space

#39

Post by vvolhejn »

jondwillis wrote: post #5
mewpmewp2 wrote: post #4

Earlier quoted context omitted.

This is what it is supposed to do. The coordinates in map from one location to another change from distance to how much time it would take to reach there.

You cannot pan on iOS.

Sorry, that must be a bug. On desktop the map is large enough to be visible in its entirety but it is supposed to pan on mobile... I'll try to fix that

Re: Maps that show time instead of space

#40

Post by vvolhejn »

rottencupcakes wrote: post #8
danbruc wrote: post #6

See also isochron map [1]. [1] https://en.wikipedia.org/wiki/Isochrone_map

These actually point of a failure mode of the original topic's visualization, at least as it pertains to public transit: https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Ma... (I think a previous commenter called this out by referring to subways as "wormholes") As for car directions, you should be able to create an isochron by drawing circles in the transformed map!

Yes! The fact that isochrones become circles is one of my favorite things about this. I also discuss this in the video (https://youtu.be/rC2VQ-oyDG0?t=134) I made about these.
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