Friction and Earth's Orbit
Is it true that there is minimal friction in space?
If so, there are still particles in the space that touch Earth.
If there is minimal friction in space does that mean that the earth
will fall in to the gravity of the sun, because its speed is being
reduced by the friction?
There is minimal friction in space because there are very few particles with
which to make contact. There is no significant gravity in space. Huge
objects, such as planets, moons, and stars, feel and exert enough gravity to
stay together in solar systems and galaxies. Objects such as rocks just
bounce off each other. The fact that gravity holds everything tightly to
the ground, and tightly together, is why friction matters so much on Earth.
As the Earth crashes into meteorites and other small objects, it does slow a
very small amount per year. The death of the Sun will be more important.
The Sun is a medium mass star. When it starts to die, it expands into a
"red giant". This will destroy the Earth long before spiraling in can
Dr. Ken Mellendorf
Illinois Central College
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Update: June 2012