Which Way is Really Up?

[Meistro]

Hi I'm new here. I don't know where to post this question so I'll do it here. Moderator please move if necessary.

In my mind, "UP" means away from Earth. When I see a model or image representation of the solar system it always seems to be represented the same, horizontal. How was it decided years ago that the top half of our planet is the top? How do we know the solar system isn't vertical. It seems to me that "UP" is purely perspective. Is there "UP" in space?

I'm going to take a wild guess that flat earth had a say in it years ago. Or the fact that most of what we know of the cosmos in early times was discovered by people in northern hemisphere?

This is either a really stupid question that an 8th grader or one who remembers 8th grade might answer or a long discussion about how we as humans perceive which way is up when not on Earth and how that became to be. Do they have up on the ISS? Is the ISS positioned out there orbiting earth so that they are facing up? Strange topic I know.

 

[Helio]

When I see a model or image representation of the solar system it always seems to be represented the same, horizontal. How was it decided years ago that the top half of our planet is the top?

Early scientific works were initiated in the northern hemisphere and science is always about appearances (observations), so "first come, first serve", I suppose.

How do we know the solar system isn't vertical. It seems to me that "UP" is purely perspective. Is there "UP" in space?

I think it might be impossible to describe any positional angle without an implicit or explicit reference frame. We use gravity to give us "Up" since it works so well with "Down" due to gravity, so the Earth is indeed the reference frame for this "up".

In space, there would be little need for "up" but it may help since, again, some frame of reference is essential when communicating with others even if just inside a spaceship.

I'm going to take a wild guess that flat earth had a say in it years ago.

I doubt it. Only gravity is needed to give us an "up" regardless of topography or planetary shapes. Besides, Aristotle's spherical Earth, along with his great arguments were so powerful that the Church infused it into their religion in the 13th century, IIRC. [It (ie Geocentricity) was one of the problems Galileo encountered.]j

Or the fact that most of what we know of the cosmos in early times was discovered by people in northern hemisphere?

Agreed.

Do they have up on the ISS? Is the ISS positioned out there orbiting earth so that they are facing up? Strange topic I know.

That's an interesting question. The ISS has a cupola that allows astronauts to observe space and the Earth. I would guess that they would put the ISS in rotation, with occasional minor corrections when necessary, to keep the cupola facing Earth. This would give them a reference frame if they wanted to assign things as up or down within the station, but it may be that they don't need to bother using those terms since they probably just address a specific location without the need for many adjectives.

 

[Meistro]

Wow that got me thinking. I wonder if this has anything to do with it. Orion correlation theory