6 comments

  • petee 4 hours ago
    I did a show and tell for an elementary school class of my astronomy hobby with a tracking telescope and sunfilter. One of the best things happened accidentally when the tracking died, but the kids ended up really amazed by just how fast the sun was moving out of view, and getting to manually chase it; otherwise it would have been a cool but fairly boring view
    • smorgasborg 2 hours ago
      exactly. this takes me back to the low-tech beginnings
  • dylan604 6 hours ago
    This is an interesting concept. I also like the idea of projecting onto a ceiling of a room. It is always surprising the first time you try using an non-tracking telescope to see how fast the earth is turning. This gives you that without a telescope being necessary.

    I block location requests, so it's just showing me the default location as Stonehenge. It would be interesting to allow the user to manually add location coords.

    • leetrout 6 hours ago
      I _LOVE_ watching the moon transit my view port in my telescope. Love being reminded of this movement. The bigger planets are fun too.
    • smorgasborg 2 hours ago
      > It would be interesting to allow the user to manually add location coords

      shouldn't be hard. one difference is moving to a much higher/lower lat. to see the difference in angular speed. Where would you want to see?

      • dylan604 2 hours ago
        32°
        • smorgasborg 2 hours ago
          https://smorgasb.org/zenith32/

          was quicker to hardcode one, then add the feature

          • dylan604 1 hour ago
            that's all sorts of awesome! thanks!

            just as part of that hacker spirit, I tried changing the 32 to a different value in the url...:thinking-face:

            • smorgasborg 1 hour ago
              lol. not a bad idea, but no, that didn't work. encoding latitude as a URL param... could save me from having to make a ui. it'd be something like ../zenith?lat=35.2N
              • dylan604 56 minutes ago
                and if you wanted to adjust the timezone you could add &lon=

                again, admitted scope creep.

                I just hate that browsers allow for location data to be used. Sure, there's some cool/fun things that can be done like what you've done, but it's too easy to abuse it. Adding features like this that allow the user to set it, especially if they wanted to see what it looks like from a different location, would be less invasive while adding more features. Just so you know, even if I open gMaps, it guesses my location based on IP because I damn sure don't share with theGoog.

  • meta-meta 4 hours ago
    This is very cool! Will definitely project on the ceiling.

    I am struggling a bit with this explanation though:

    > ZenithTrack shows a strip of the sky, a thin ribbon, one rice-grain tall, about 2,500 rice-grains long.

    What does it mean to say "one rice-grain tall"? Is that angular diameter at arm's length?

    • smorgasborg 2 hours ago
      yes. the Field of View is the size of a grain of rice at arm's length. the total "movie" you see is like 2500 of those rice-grains, end to end (earlier in the explainer, it mentions the FoV size)
  • a-kgeorge 5 hours ago
    This is fantastic. I love how it makes Earth’s rotation feel immediate and visceral with zero equipment. The controls and overlays are really well thought out. It would be cool to have a search box to jump to a specific star or coordinate, even if most things in the ribbon are obscure.
  • smorgasborg 2 hours ago
    I'm the dev. happy to answer questions.
  • toss1 4 hours ago
    Very cool!

    You can do this with the naked eye in an area with tall sharp mountains such as the Alps, Rockies, Andes, etc. at times when the moon is low in the sky.

    Move to a position where the moon is partially obscured by a mountain across the valley, and watch. It is surprisingly easy how little walking it can take to find a useful alignment. Then just stand and watch. The effect is amazing, even more powerful than watching it drift out of frame the telescope — it really shifts one's perspective to feeling how the earth moving.

    • dylan604 4 hours ago
      It's even easier to see twice a day with sunrise and sunset!
      • toss1 1 hour ago
        Yes, I've seen that too, and you can get the sensation.

        But it is not nearly as vivid a sensation as the moon against a sharp edge of an alpine slope a couple km across a valley (vs all the way to the horizon).

        The difference is on the scale of imagining being traveling in a railway car vs actually being in one. Once I saw it, it wasn't unlike being on a smooth Swiss rail just starting to pull out of the station...

        • dylan604 1 hour ago
          Well, not everyone lives in mountains, so it was a pretty specific example. You could say the same thing about someone living in a city with tall buildings. You can just stand there and watch the moon climbing from behind them. There's a popular spot in my city that is a good distance from downtown so you see the skyline where photographers will line up to capture the moon rise behind downtown. You can tell the newbies by how casual they are about what they are doing vs the experienced ones that know once it starts it's over in a matter of minutes.
          • toss1 12 minutes ago
            Yes, big city buildings could work very well for that!
      • smorgasborg 2 hours ago
        exactly. that's the only other time you can get that sense. (or moonrise/set)