In the absence of any external force or interaction (ie gravity,
friction etc) will a spinning object continue to spin at the same rate
for ever or will it gradually slow down?

2nd_quadrant-ga 

Spinning object will continue to spin at the same rate.
This is called conservation of angular momentum.
http://hyperphysics.phy-astr.gsu.edu/hbase/rke.html#rke



also can be seen as consequences of the Newton's second law for rotation.
 http://hyperphysics.phy-astr.gsu.edu/hbase/n2r.html#n2r


 Objects executing motion around a point possess a quantity called
angular momentum. This is an important physical quantity because all
experimental evidence indicates that angular momentum is rigorously
conserved in our Universe:
http://csep10.phys.utk.edu/astr161/lect/solarsys/angmom.html

Historically, the law

Angular Momentum is "conserved" means L is a constant. 

 is a form of the Second Law of Kepler:
Planet sweeps out equal areas in equal times.

http://www-astronomy.mps.ohio-state.edu/~pogge/Ast161/Unit4/orbits.html

which was important step in formulating Newtons Laws.
Hedgie

Thanks a lot, great answer. Like the different types of references
that expand and support the answer

If it is not losing any energy (as a result of an electrical or magnetic field
or any material that surrounds it) it will continue to spin forever.
Mongolia

Energy is the substance of the universe, and this is as about as far
as our understanding of energy goes. As we know, a spinning object in
a vacuum is offered no resistance, so theoretically it would spin
forever. But I offer these thoughts; a vacuum is full of energy which
offers no resistance, so the relationship between energy here is one
we vaguely understand, and forever means eternity which means forever.
Forever would refer to time, whitch is a man made tool used to measure
passing. Time doesn't exist, there for, your question cannot trully be
answered.

If you wish to except this answer would you be willing to agree that
yes this does answer the question of an object spinning freely with
out resistance, indefinitly. But forever is an awful long time. You
might want to consider that even the cutting edge of quantum physics
is revealing that life is governed by belief and choice.

Airspace,
1) This question was asked primarily to resolve a technical debate
within the office and as such the answer given means that my colleague
accepts that I was right and he was wrong and the beers are on him. To
that end I am more than satisfied with the answer given.

2) You are right in saying that forever is a long time and we probably
don't understand all that happens with interactions of energy and
matter over time within the universe. So can we state that it will
continue forever in the real universe - almost certainly not because
there will inveitably be external influences. My question however
stated an absence of external forces and interactions and therefore
postulated a simulated "perfect" environment.

3) I would suggest that both views are correct as after all we are
getting into the mathematician, physicist and engineer dabate where
evryone is right and wrong at the same time.

Any spinning object in the this universe will slow down after time, as
there is always some other mass around it,
if it was spinning in a frictionless and empty space then it would spin forever,
If it could be measured you would find that earth rotates slower every
day, but by a very small amount such as a few seconds ever 100 years
or so.

Thank you for your responce and indeed, enjoy the beer.

The answer is no, it won't spin forever, it will stop someday... why?
Because by spinning it will drop atoms, at a low rate, but in a long
long time it will finally lose all it's mass.

And what about a boiled egg and a raw egg?? Raw eggs tend to stop much
faster than boiled eggs, try that experiment. ;)

Hello, 
The entire universe is spinning, galaxies, solar systems, black holes,
stars, planets, moons, protons, neutrons, electrons, quarks, gluons,
pi meson; even photons are spinning as they travel through space. The
universe's spin is a direct result of the big bang. High energy
created from membranes impacting on dimensional levels created a "big
explosion" and massive amounts of energy were released. I would be
willing to bet that in the future the spin rate of our quantum
universe will be found to be directly related to the age of this
universe.
As the energy of the universe falls or is lost (like everything else
in nature) the spin rate will decline in proportion until the energy
from the initial "big bang" has been depleted.