The “we” in the article refers to those to whom this level of semantic parsing matters.
Regarding this law though: what about a magnetically suspended top, spinning in a vacuum? Are there still forces acting upon it to slow it down?
Questions like this keep me awake at night...
Wouldn’t it depend on the torque in the magnetic field?
Take Benadryl.
Regarding this law though: what about a magnetically suspended top, spinning in a vacuum? Are there still forces acting upon it to slow it down?
= = =
Magnetic forces are suspending it.
And probably will result in slowing it.
And if you can really get a vacuum.
I think it tightens up the semantics.
An object at rest is, at all times, influenced by the “outside” force of gravity pulling it toward the surface it rests on (actually pulling it to earth).
As well as the gravity of the body itself pulling the surface toward it.
For every action, there is an equal and opposite reaction then becomes recognizable as “a body at rest”.
A vacuum pressure measurement device called a spinning rotor gauge uses a small steel ball bearing suspended in a magnetic field. The friction of gas molecules will cause the rotational speed of the ball to decline. At very low pressures it takes a while to get a useful measurement.
Yes. There is no perfect vacuum. At the least there are hydrogen atoms to collide with.