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Name: Jacquie B.
Status: student
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You answered a question of is there friction in space. I recently read that the density of particles or atoms in space is about 1 atom to ever cubic yard of space. If this is correct, I have been searching for the coefficient of friction in space in reference to the amount of particles which exist in space. If a craft could travel at the speed of light or faster, what would be the assigned number of the coefficient of friction with the amount of free atoms or particles (not dust and rock)in space. For example the TV show Voyager, if Voyager did not have shields and as Voyager was traveling at the speed of light or faster the atomic particles would hit the ship and create heat. Voyager's computer would have the coefficient of friction stored in its computer for this formula.

Jacquie, Friction results from one surface rubbing against another. Friction is not the correct quantity for which to look. Air resistance is a better model. Air resistance is due to the mass density of a gas and the relative speed of an object moving through the gas. The shape and size of the object can also be important. A ball-shaped ship would hit more matter and feel more resistance than would a needle-shaped ship. At small speeds, this would not be important. It could start to matter at high speeds. Read up on air resistance to get a better idea of what might happen.

Dr. Ken Mellendorf
Physics Instructor
Illinois Central College

Faster-than-light travel of a spaceship is simply not possible given our current understanding of the universe. Relativity tells us that the mass of an object approaches infinity as it approaches light speed, and therefore no matter how much you (finitely) accelerate, you cannot ever reach light speed. So this question is not really answerable with science. If you invent some special way of traveling faster than light, such as 'warping' in Star Trek or some other kind of discontinuous path through space, the concept of friction might be meaningless there as well.

In space, radiative heating -- heat generated from electromagnetic radiation (such as from light) -- will cause more heating than friction. There are so few particles in deep space that frictional heating is pretty much zero. Voyager should be more concerned with radiation than with friction.

Hope this helps,

Burr Zimmerman


You ask a very difficult and very good question. Keep them coming.

Unfortunately, this question is outside my area of expertise, but I am attaching two papers on the subject I found while searching online. I hope these help to answer your question. If they don't, I would recommend looking at the references section of each paper to see if there are other papers that may address your question more directly.

Aaron Brown

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