Maybe I am focusing to much on the weight issue and not enough on other factors that can have significant impact on a top, such as air resistance.

You have to worry a lot about weight in a throwing top, but it's generally a minor consideration in a high-performance pocket-sized finger top meant to spin in place. In the latter case, it's generally

*much* more productive to fret over center of mass height, mass distribution about the spin axis, aerodynamics, and ground clearance. Tip friction is the only performance factor that depends on weight per se without regard to how the weight is distributed through the top, and you can generally limit tip friction by choosing a very hard, low-friction tip material, maximizing tip smoothness, and minimizing tip radius of curvature. Bear in mind, though, that the overall performance hit due to aerodynamic drag is generally much bigger than that due to tip friction -- even in very smooth tops.

This I still don't understand because isn't weight the resulting force that we are measuring? For example in space the mass would be the same but not the gravitational pull and therefore isn't weight at any given time subjective to the strength of a gravitational influence?

Yes, and the acceleration of gravity

*g* measures the "strength" of the gravitational field (influence) at a given point in space.

But if we took a top to place where there is a vacuum AND no gravity, how is weight measured? Is that where "weightless" comes from? But it still has mass.

The vacuum is irrelevant here. Where there's no gravity, the local

*g* = 0. And since the magnitude of the weight

*W* =

*m* *g*, the local weight

*W* = 0, too -- regardless of the mass

*m* involved.

....not the weight, which is almost 10 times larger and measured in Newtons.

***I will go study about Newtons although I understand that is a unit of measurement, I don't full get what is being measured exactly.

Weight is by definition the force of gravity. Forces are properly measured in Newtons (N) in the International System of Units -- "SI" for short. (Don't get me started on Imperial units.) The SI unit of mass is the kilogram (kg). The kilogram-force (kgf) unit mentioned by ta0 is

*not* an SI unit, and the SI folks discourage its use. Hence, I prefer to interpret digital scale readouts in the way I outlined earlier. For scales near the Earth's surface, my interpretation is for all intents and purposes equivalent to ta0's.

- comparing forces on a top, how many are there other than gravity? Do you mean things like density, inertia, stored kinetic energy?

Aerodynamic drag and tip friction are ultimately due to viscous, inertial, frictional, and elastic forces acting on various parts of the top. If the top is thrown, or is twirled in a breeze or on a moving surface, additional forces enter the picture. And if a top has moving parts, like the centrifugal tops below, or has inadequately secured parts or too much flex, then centrifugal forces also come into play.

https://www.youtube.com/watch?v=nTNyuuhw04sAll of these forces can affect top behavior in visible ways.

- gravitational torque? What torque? I understand the pull of gravity will have an effect on friction of the contact point but I am still having a hard time understanding where is the break even point (if that's what it is) between the advantage of more weight and kinetic energy to the increased friction it will cause on the tip. Also another thing I struggle with is where the weight distribution is best given a tops size so to get the best ratio of spin time at lower revs but still has the most weight possible. If the increased friction isn't such a big issue especially for a small top, then it seems there would be a math formula for a spinning speed that an average person could hope to attain, which would give the best weight/mass distribution of a given size of top. I think that's way too much for me to get into, but basically as far as I know it's true that if a few tops of exactly the same proportions but of greatly differing weight are spun exactly the same then the heavier one will spin longest. Foreverspin has said their tungsten tops spin longest for example.

We'll have to take this up another day, but consider an ideal top with its center of mass (CM) and tip exactly on the spin axis. If that axis deviates even a hair from the vertical defined by local gravity, the CM will no longer be directly over the point where the tip contacts the ground. Since gravity acts vertically through the CM, it will then exert a torque on the top about its tip. This gravitational torque is what ultimately brings the top down.