5 ms·

Does it account for geological drifting? This is probably the most important social issue with these kind of systems.

mchannon 8y ago
Not OOTB, but I would imagine that any geocoding system could include a suffix, like "(1987)", to know which dataset to use, so as long as there was a server providing accurate geocoding for a particular point in time. This is a service-related question, though, not a method-related question. There's no math equation that'll tell you your house is there when it used to be here.
- yorwba 8y ago
  The formula might not be elegant, but if you have an exact description of tectonic drift, you can absolutely have a code that refers to a fixed location on its plate, rather than to a point on some imaginary sphere. GPS coordinates are just one possible solution, there's no reason to consider equivalent encodings of the same values as the only alternatives.
  - dragonwriter 8y ago
    > The formula might not be elegant, but if you have an exact description of tectonic drift, you can absolutely have a code that refers to a fixed location on its plate, rather than to a point on some imaginary sphere. Sure, but (1) is there a good way to get an exact description of tectonic drift?, And (2) does tectonic drift account for all shifts of surface features (intuitively, it would not necessarily for features not fixed to bedrock, which accounts for a very large share of interesting-to-humans features)?
    - yorwba 8y ago
      (1) By measuring the location of a few designated landmarks, it should be possible to extrapolate tectonic-level shifts to all other points on the same plate pretty accurately. (2) Changes on a smaller scale, e.g. due to a landslide, are probably less surprising when they cause a change in location codes. On the other hand, there might be some houses on a hill somewhere slowly sliding down, where the system doesn't work. (I also realized that my previous comment can be read as supporting a flat earth theory, especially the part about the sphere being imaginary. I firmly believe that the earth is a bumpy ellipsoid, though.)
      - dragonwriter 8y ago
        > By measuring the location of a few designated landmarks, it should be possible to extrapolate tectonic-level shifts to all other points on the same plate pretty accurately. I would think you'd need a lot of targets near plate boundaries (where deformation is high for that reason) as well as in known regions of intraplate deformation.
      - deleted 8y ago
        [deleted]
    - jerf 8y ago
      Fully accurately, you'll only be able to get retrospective locations (and probably some interpolation thereof), for pretty much the same reason that I can't actually tell you for sure exactly how many seconds the next decade is going to have. We won't know how many leap seconds it has until it is over, or the standards body commits to including no more. But I can tell you exactly how many seconds there were in 2000-2009 inclusive.
    - michaelt 8y ago
      Geographers already have a system for recording positions relative to continental plates - in Europe that means ETRS89 [1], North American NAD-83 [2], Australian GDA94 and so on. Of course, getting all software to support multiple datums might be a complicated matter, as 98% of things like online slippy maps and mobile phone geolocation APIs just use WGS84, the familiar datum used by GPS. [1] https://en.wikipedia.org/wiki/European_Terrestrial_Reference_System_1989 https://en.wikipedia.org/wiki/European_Terrestrial_Reference... [2] https://en.wikipedia.org/wiki/North_American_Datum https://en.wikipedia.org/wiki/North_American_Datum
- __jal 8y ago
  ...Which defeats the "simple" in 3-words pitch. "No, I'm `heartfelt-triple-coma` from 2003, not current. Oh, you're using a Spanish-language phone; I don't know which dataset you use."

Not OOTB, but I would imagine that any geocoding system could include a suffix, like "(1987)", to know which dataset to use, so as long as there was a server providing accurate geocoding for a particular point in time. This is a service-related question, though, not a method-related question. There's no math equation that'll tell you your house is there when it used to be here.

yorwba 8y ago
The formula might not be elegant, but if you have an exact description of tectonic drift, you can absolutely have a code that refers to a fixed location on its plate, rather than to a point on some imaginary sphere. GPS coordinates are just one possible solution, there's no reason to consider equivalent encodings of the same values as the only alternatives.
- dragonwriter 8y ago
  > The formula might not be elegant, but if you have an exact description of tectonic drift, you can absolutely have a code that refers to a fixed location on its plate, rather than to a point on some imaginary sphere. Sure, but (1) is there a good way to get an exact description of tectonic drift?, And (2) does tectonic drift account for all shifts of surface features (intuitively, it would not necessarily for features not fixed to bedrock, which accounts for a very large share of interesting-to-humans features)?
  - yorwba 8y ago
    (1) By measuring the location of a few designated landmarks, it should be possible to extrapolate tectonic-level shifts to all other points on the same plate pretty accurately. (2) Changes on a smaller scale, e.g. due to a landslide, are probably less surprising when they cause a change in location codes. On the other hand, there might be some houses on a hill somewhere slowly sliding down, where the system doesn't work. (I also realized that my previous comment can be read as supporting a flat earth theory, especially the part about the sphere being imaginary. I firmly believe that the earth is a bumpy ellipsoid, though.)
    - dragonwriter 8y ago
      > By measuring the location of a few designated landmarks, it should be possible to extrapolate tectonic-level shifts to all other points on the same plate pretty accurately. I would think you'd need a lot of targets near plate boundaries (where deformation is high for that reason) as well as in known regions of intraplate deformation.
    - deleted 8y ago
      [deleted]
  - jerf 8y ago
    Fully accurately, you'll only be able to get retrospective locations (and probably some interpolation thereof), for pretty much the same reason that I can't actually tell you for sure exactly how many seconds the next decade is going to have. We won't know how many leap seconds it has until it is over, or the standards body commits to including no more. But I can tell you exactly how many seconds there were in 2000-2009 inclusive.
  - michaelt 8y ago
    Geographers already have a system for recording positions relative to continental plates - in Europe that means ETRS89 [1], North American NAD-83 [2], Australian GDA94 and so on. Of course, getting all software to support multiple datums might be a complicated matter, as 98% of things like online slippy maps and mobile phone geolocation APIs just use WGS84, the familiar datum used by GPS. [1] https://en.wikipedia.org/wiki/European_Terrestrial_Reference_System_1989 https://en.wikipedia.org/wiki/European_Terrestrial_Reference... [2] https://en.wikipedia.org/wiki/North_American_Datum https://en.wikipedia.org/wiki/North_American_Datum
__jal 8y ago
...Which defeats the "simple" in 3-words pitch. "No, I'm `heartfelt-triple-coma` from 2003, not current. Oh, you're using a Spanish-language phone; I don't know which dataset you use."