Editing 2800: Down
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For example, a commonly-used coordinate system for Earth is the {{w|Earth-centered, Earth-fixed coordinate system}}, which defines the origin to be Earth's center of mass, and uses three pairs of points on the Earth's surface to define the directions of the three spatial dimensions; this allows any point relative to Earth to be specified as a triplet of three coordinates. Presumably, the coordinate system now used in the comic is a "Mars-centered, Mars-fixed" coordinate system, which would be good for things like launching satellites from Mars, but otherwise not very useful for most Earthly situations. | For example, a commonly-used coordinate system for Earth is the {{w|Earth-centered, Earth-fixed coordinate system}}, which defines the origin to be Earth's center of mass, and uses three pairs of points on the Earth's surface to define the directions of the three spatial dimensions; this allows any point relative to Earth to be specified as a triplet of three coordinates. Presumably, the coordinate system now used in the comic is a "Mars-centered, Mars-fixed" coordinate system, which would be good for things like launching satellites from Mars, but otherwise not very useful for most Earthly situations. | ||
β | In the title text, Cueball states that he gets nervous about heights. Height is the distance between two points at different elevations, and elevation depends on which way "down" is - therefore, redefining down also redefines the concept of height. Since down now points toward Mars, and Mars is millions of miles away (about 34,000,000 mi or 55,000,000 km at closest approach), this means that Cueball - and indeed, everyone on Earth - is now standing at a height of about 34 million miles above Mars. | + | In the title text, Cueball states that he gets nervous about heights. Height is the distance between two points at different elevations, and elevation depends on which way "down" is - therefore, redefining down also redefines the concept of height. Since down now points toward Mars, and Mars is millions of miles away (about 34,000,000 mi or 55,000,000 km at closest approach), this means that Cueball - and indeed, everyone on Earth - is now standing at a height of about 34 million miles above Mars. However, it doesn't really make sense for Cueball to have such an anxiety in this instance - usually, when people are afraid of heights, it's because they are afraid of falling. However, gravity still points toward the center of the Earth, so Cueball is in no danger of falling to Mars. Probably Cueball's problem is that he is on the side of Earth pointing towards Mars, so he feels that there is empty space below him. When the Earth rotates to the other side, he would again feel down being towards Earth. |
The only advantage of using Mars as down, is that everyone on Earth agrees on the direction of down, since Mars is so far from Earth that even those on either side of Earth orthogonal to the direction towards Mars, would still almost agree on the down direction. | The only advantage of using Mars as down, is that everyone on Earth agrees on the direction of down, since Mars is so far from Earth that even those on either side of Earth orthogonal to the direction towards Mars, would still almost agree on the down direction. |