> […] it’s a nice trick if you can do it, but it’s better when you can do it at any time, without an app. Which is what happened. > > First I got good at figuring out the ecliptic. That’s the flat disc of the Earth’s orbit (and the solar system). If you wave your arm along the path that the Sun makes across the sky, that’s the disc. > > Then I can’t remember how I would locate Sagittarius each day (it lies on the ecliptic) but I trained my intuition by checking the app each day. Over the weeks and months, I could follow how the position changed (at the same time each day as I caught the bus). First through the ground that way, then under the ground further that way, and so on. > > Eventually then I had this picture of myself, and the Earth, and the solar system, and the centre of the galaxy which had initially been whirling round me, and now it had flipped, I was turning around it.