If there is no up or down in space, then what is direction?
-------------------------------------------------------
answers:
Zheia say: Imagine two astronauts are in deep space, one is floating upright, the other upside down. The upside down one will see the other astronaut upside down because from their viewpoint they are the one who is upright. So being upright or upside down depends on one's viewpoint. In deep space there would be little or no gravity, and up would be from your head upwards, and down would be from your feet downwards. The upside down astronaut would think the same thing from their viewpoint: their up is the other astronaut's down, but neither astronaut is the right way up or upside down. It's only when they are near Earth or another planet that gravity would create a sense of downward pull and an up or down.
-
Clive say: Whatever you choose it to be. Up and down on Earth is only because of gravity. If there is no gravity pulling you any particular way, then obviously up and down have no meaning.
-
snorkeling_llama say: Everything has its own gravitational core, so direction is based on what is moving where.
-
Jeffrey K say: You can choose to orient your coordinate system any way you want. Make a wise choice to take advantage of any symmetry in your physics problem.
You can use Cartesian coordinates, spherical coordinates, cylindrical coordinates, or any other system that fits the problem.
-
Cowboy say: Everything's relative.
-
aladdinwa say: We have up and down on Earth, because Earth's gravity pulls us onto and holds us on the surface. "Down" is toward the surface you are being pulled onto by gravity.
In space, you are floating. You are not being pulled onto a surface by gravity; so there is no "down" and, consequently, no "up".
-
John say: There is no objective up or down or north or south but there IS direction. Obviously a comet is moving from point A to point B. To figure it out as humans, we use "vectors", which are mathematically defined lines. And a 3D grid. We say that Earth (for instance) is at the center of the grid. We draw a line from that to a point on the grid (which we will call Venus) and so we have moved to a new place. From that point we can calculate how to get to another point, or how to return to Earth. In basic terms this is actually how navigation in space works. In reality it's not so simple because everything is in motion already.
-
Ronald 7 say: Relative to where you are going
-
hoarseman say: All directions are relative to your defined coordinate axes
-
K say: Notice when people talk about space they point upward and sat north regardless of what part of earth they're on.
-
Michael say: If there is no gravity in space how do bodies in space exert gravitational forces on each other ?isnt that what gravity is?someone should pls educate me?
-
Sky say: Direction is always relative to a reference point. Up is in the direction opposite gravity, while down is the direction with gravity. When in space and there is no gravitational reference point, there is no up or down. There's just "over there" and "thattaway".
-
Colleen say: Everything is relative.
-
MysteryGuy say: You can choose what up or down is.
The standard definition of up is going towards the sky and down is down the earth.
While doing physic calculation you can literally decide which way you want up to be as long as you are consistent you will get the same answer.
-
Tom S say: Direction is relative.
-
quantumclaustrophobe say: "Up" and "Down" are in reference to some other object - the floor, the ceiling, the wall, etc...
In space, you can point in a direction, and set a course based on where you are versus where you'd like to go.
-
say: when you sit on the flat Earth - up is right above you, so I don't see what the problem is. Down - if you dig right through it into the opposite side.
-
RAJ say: the universe has no direction /. no center
-
Penn say: there is not direction because there is no force applied to people in space then on earth. so basically your always resting your body when your standing if that makes sense. and in space you loose body mass because there is not force applied to hold you down so they have to work regularly to keep good body mass
-
say: Wherever you want to go
-
oneofmagi@rocketmail.com say: According to their choice and promise.
-
Nikki say: when peter pan went to neverland; the star right from the Northern star ("second star to the right and straight on 'till morning").
conceivably, we could just head straight across the milky way galaxy, exploring as we go. however, it took the two voyager space probe explorers many years just to exit this "sol" solar system.
we have only really managed to go 150,000-miles into space.
On average, the distance to Mars from Earth is 140 million miles (225 million kilometers), according to NASA.
-
busterwasmycat say: there is an up and a down, but it is arbitrary. You get to choose. Up and down on earth is equally arbitrary. It is not the same direction here as in a place 500 miles from here, even if you want to think it is.
-
Morningfox say: But that is wrong, there IS up and down in space. It's just that in micro-gravity, those directions are arbitrary. In near-Earth orbits, "up" is (usually) picked as away from Earth. In deep space, 50,000 km from Earth, "up" is picked as from the center of your spacecraft toward some particular part of the spacecraft (the "top").
Navigation when away from Earth is (almost always) done with an X-Y-Z system, with each axis defined as pointing toward certain stars or quasars. For example, the Z-axis points very close to Polaris, the North star. The X-axis points so that quasar 3C 273B has a right ascension of 12h 29m 6.6997s.
-
Bill-M say: Your correct there is no up or down. Direction in space is relative to something out there. Direction - towards the Moon or Towards to Sun.
-
CarolOklaNola say: Up is away from a celestial body, down is toward a celestial body.
Please state WHICH coordinate system you are using. There are at least 4 of them.
-
KennyB say: However you define it. Astronavigators use the earth (or the sun) as the point of origin and spherical geometry as the coordinate system. Note that they must arbitrarily define a direction as "up" so you are free to make that choice on your own and have your own definition of up and down.
-