Could the earth be weighed to prove it is hollow?

What procedure could be used to weigh the earth? If we can cat scan it can we weigh it? Does it's weight increase with constant expansion?

We know how much the earth mass is, because we can figure how much influence it has on the moon (the moon orbital characteristics depends on only two factor: how far it is from the earth, and the mass of the earth).For this, and knowing the size of the earth, we can compute a density, which is pretty high at 5.5. Knowing that the center of the earth is very hot (the lava coming out of volcanoes is a fairly good proof) one can easily deduct that:- the earth is essentially molten rocks, with just a very thin solid crust- the pressure and temperature increase very quickly going downand thus no hollowness could survive, as there is no material strong enough to support that kind of pressure, especially in molten form.The mass of the earth is essentially constant, save for the contribution of falling meteorites.

The old professor says: We DO kind of "cat scan" it when we do seismic studies of the shock waves going through it as the result of earthquake activity. No need to weigh it when the seismic data pretty much answers your question. Most lava comes from magmas that are from the crust itself (andesitics for example) or upper mantle (basaltics). Near the center of the planet is a core of iron and nickel with traces of other heavy elements. We know this because of the study of the planet's behavior in relation to other solar system bodies and the applications of newtonian physics in addition to meteorite studies and seismic shadow zones. (see the previous answer)

Will you help me heave it onto the scale?