Question:
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.
Replies:
It is not appropriate to use the "average" density of "free"
particles in space in determining the coefficient of friction.
The coefficient of friction is a characteristic of particles
whose average position remains constant as two surfaces in
contact slide against one another. It makes sense that the
gravitational attraction between two masses in contact plays
a role in the "drag" between them. However, even in the
absence of gravity, van der Waals forces (always attractive)
tend to attract. Invoking the "results" of supra-luminal speeds
from a TV show is not a particularly reliable source of
scientific data. In any case, the interaction of surfaces,
whether in a vacuum, or in the presence of gases is a really
difficult problem to analyze -- both theoretically and
experimentally. So I cannot make an educated "guess" of how
their data bank would respond.
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