Directions and Orientation is Space
Date: Summer 2012
How is orientation in space determined? Since there is no proper up/down/left/right based on gravity, etc. We always see fiction portrayed with vessels being properly oriented, but what truly is proper?
You are correct, space has no preferred orientation, as far as we can tell. Any orientation is as good as any other. When you speak of vessels in movies as being "properly oriented," that probably means that they look right to our earth-bound sensibilities. That very well might not be optimal for operations in space.
Richard E. Barrans Jr., Ph.D., M.Ed.
Department of Physics and Astronomy
University of Wyoming
You have identified one of the fallacies of science fiction in movies and television. Why do spacecraft always approach one another “right side up?” Should they not approach at all different angles, sometimes even “upside down?” Two other fallacies you can think about are, “Why do we hear guns (lasers, phasers, etc.) and explosions firing in space?” and, “Why do we see the lasers shooting in space if we are not looking right at the lasers?” You can think of these as well. As for sound, I understand that when the originators of “Star Trek” (original series) had their opening scene with the Enterprise flying across the camera, they originally thought to keep it silent. It did not feel right, so they put in a “whooshing” sound. Much better. Not science, but good TV.
There is no “proper” direction to space. It is what we decide makes sense is what we choose. On earth, North points “up” on maps (although this is not always the case). If we are in space, we could choose to reference certain ways to orient that make sense. “Up” might be decided as the direction with respect to the rotation of the solar system. If we take our right hand and wrap our fingers in the direction of the rotation of the solar system, take our thumb and extend it, the direction it points could be decided as “up.” If we do the same with our galaxy, we could decide that direction is to be called “up.” We could also use direction based on star systems and directions between them. Since, contrary to science fiction, we are not regularly traveling around the galaxy (yet), we do not yet know what will be decided as the proper definition of up.
Kyle Bunch, PhD
You are correct that on the level of the Universe, there is no preferred direction. However, it is possible to measure and specify the orientation of a space object RELATIVE to other objects. The Earth and Sun are a good example. Relative to the Sun, the Earth has several motions: around the Sun, varying tilt with respect to the Sun, the Earth’s spin about its polar axis, and several more. These motions are measured relative to the position of the Sun.
There isn't one. Just like you can navigate by stars on Earth, so too
can you navigate by stars in space. And you can assess your
orientation according to some reference point too. But since we are
effectively not a space-faring society, there has been no need for any
significant reference system for space the way we have map coordinates
on Earth's surface. We can just refer to locations relative to Earth
(or the moon, etc.)
Hope this helps,
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Update: November 2011