Don_DickleIn space how does one tell what direction being no fixed point? Or how does one tell up from down and so on?
Jul (they/she)You pick a point of reference. Most things use the plane of the solar system or the Milkway Galaxy and the general direction the earth’s north faces as “up”. And then angle of inclination/declination from there.
Hate to bother. But can you break that down for a lamen?
You always have to define what “up” and “down” mean. On earth, we define “down” as the direction gravity pulls, and “up” as the opposite of that. But out in space, that definition obviously doesn’t make sense, which is why you’re asking.
So either,
One of the common definitions astronauts come up with is relative to the “plane of our solar system”. If you can imagine a giant piece of paper cutting through the middle of the sun, and extending out so big that it also cuts through all all the planets that are orbiting it, that’s called the plane of the solar system. Then we say “up” is one side of that paper, and “down” is the other side.
But again, that only works as a convention in our solar system. Wherever you are, you have to define up and down, because they don’t mean anything by themselves.
agamemnonymousBuckminster Fuller didn’t like to use “up” or “down”, preferring “in” (towards the center of gravity) and “out” (away from the center of gravity). “Downstairs” becomes “instairs”, “upstairs” becomes “outstairs”. A tad pedantic for casual conversations on Earth, but highlights the central issue.