Does friction exist in space?

imstrongerthanu

I'm currently in deep thought and had to ask this random question.

niallith

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Friction in Space
Does friction exist in deep space?

Yes, when two surfaces rub together in outer space, there will be friction. Friction is a surface effect and doesn't depend upon there being air. There is also a force like air resistance from the very sparse gas in space, but it will be very, very small, since space is a very good vacuum.

imstrongerthanu

So friction works in a vacuum.What about if the 2 objects didn't touch is friction zero?

Sheeps

imstrongerthanu wrote: »

So friction works in a vacuum.What about if the 2 objects didn't touch is friction zero?

The object is moving through a vacuum, so there is no wind resistance which means an object moving through space will not decelerate until it meets an opposite force to the one that has been applied to it.

meditraitor

imstrongerthanu wrote: »

So friction works in a vacuum.What about if the 2 objects didn't touch is friction zero?

Friction is not really a force, its a transfer of energy from kinetic to thermal when you rub different types of surfaces/objects(something to do with chemical bonding) against each other. It will probably(im open to correction on this) not occur in a vacume because there needs to be a force to rub these items against each other.

seamus

Friction only comes into play where objects come into contact. So if the two objects do not come into contact, then there is no friction.

However, this does not exclude the possibility of other forces:

- Two bodies coming close to eachother ("close" is dependent on the size of the object) will have a gravitational effect on each other, altering eachother's velocity.

- Theoretically you could have a large body with a magnetised core or one projecting a strong magnetic field, coming close to another body with an iron (or similar) core or composition. In this case again, the velocity of both bodies will be altered.

..and no doubt a billion other hypothetical scenarios.

But none of these are "friction" as friction is a specific force.

Theoretically, all bodies in space are subject to what we know as "wind resistance" because space is not a perfect vaccuum, and therefore any body is space will experience friction from free particles. A perfect vaccuum requires no particles to exist in it - to have a density of zero. Space contains innumerable particles but because space is so enormous, space at velocities below e is generally considered to be as close to a perfect vaccuum as you can get.

Azelfafage

It depends on how we define friction.

A piece of matter spiralling into a black hole may be defined as suffering friction.
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seamus

Azelfafage wrote: »

A piece of matter spiralling into a black hole may be defined as suffering friction.

Only if it comes into contact with something while doing so. Friction requires contact. Any non-contact force upon a body cannot be defined as friction.

enda1

I remember from engineering classes that the frictional effects are magnified in space. It becomes particularly evident on the international space station and other orbiting man made satellites where you have joints and mechanisms. Locking up and seizing becomes a major issue.

I think its related to trapped air molecules acting as a lubricant on Earth. Though not sure now...

imstrongerthanu

Some very interesting replies.
So space isn't a perfect vacuum at all.Learn something new everyday.Ok so you say friction can only happen in 2 objects touch as opposed to gravity where the mass of the object effects the forces involved.Ok I understand that now.

About the shuttle bolts having more friction in space thats fascinating.I wonder does greese work in space lol.

Turtwig

imstrongerthanu wrote: »

About the shuttle bolts having more friction in space thats fascinating.I wonder does greese work in space lol.

They use a special grease gun, I can't quite remember the details
Here's a sample of astronaut tools if you're interested.

imstrongerthanu

Some expensive gear they have up there.
Did you see on the ews at all a few meteors falling to earth recently.I heard that some fella dropped his tool bag up in space. I think one was in south africa last week and the other 2;1 of which was in florida and the other in nevada.
Guy must be out of a job now lol