3 ms·
"Same position in space" isn't well-defined anyway. There's no fixed set of coordinates permeating the entire universe. But it's clear enough what is meant in t
by pierre_M 16y ago
"Same position in space" isn't well-defined anyway. There's no fixed set of coordinates permeating the entire universe. But it's clear enough what is meant in this case.
I wonder, though, it should be in the same position in the sky, right (after accounting for the Earth not necessarily being in sync with regard to its rotation)?
I'm not sure what you mean "after accounting for the Earth not necessarily being in sync"; since it isn't in sync it won't be in the same position. But if you were viewing it from the centre of the Sun, then yes, it would be in the same position in the sky.
- petercooper 16y agoI'm not sure what you mean "after accounting for the Earth not necessarily being in sync"; since it isn't in sync it won't be in the same position. That from some point on Earth (on a similar latitude - accounting for tilt) Neptune would be in the same position in the sky (because other than the tilt, the time of day would likely be different so the longitude of observation should be too). In writing that, though, I just realized the flaw in my thinking. Not only would the rotation of the Earth not be in sync, nor would its orbit! So the chance of being able to repeat the precise observation at the specified time would be close to nil.