It would be far more likely to alter its Q.
Circulating currents induced in the aluminum would reflect losses into the inductance and the ratio of L to R would be altered by such an insertion. Since Q is critical in an RF coil this change would probably be undesirable.
Aluminum is a good conductor of heat - so it's probably not the best material to make a planter out of, especially if used in direct sunlight. The only way this might be feasible is if you used the aluminum planter as a cache pot, with a plastic pot inside it.
both, on the outside it's aluminum oxide but the inside is just aluminum
Yes.
Temperature affects a thermometer by causing the liquid or material inside to expand or contract, leading to a change in volume. This change in volume is measured by the scale on the thermometer, so as temperature increases or decreases, the level of the liquid or material inside the thermometer will rise or fall accordingly.
the air inside the can keeps it afloat
dependent on your camper. The walls (from outside to in) consist of a fiberglass outer wall, then aluminum framing with Styrofoam insulation, then usually a thin piece of paneling called luan.
It depends on what you're measuring: the density of the aluminum or the aluminum and the space inside the can. If it's the density of the aluminum only, it doesn't change much. If it's the density of the aluminum and the space inside the can, the density greatly decreases as you are getting rid of the air, and therefore the volume, inside. This also depends on if you are using your foot or a garbage compacter.
Aluminum. That is how to tell a reproduction. Just rub your finger inside of the wheel well. Rough, is a fiberglass copy. Smooth is an aluminum, which they do make aluminum copies, however, they are more quality, thus being worth more, than the fiberglass.
When a can is crushed, the volume decreases due to the change in shape. The material inside the can gets compacted, reducing the amount of space it occupies. The actual change in volume depends on the extent of the crushing.
You need to shape it into a series of turns, as you have probably seen diagrams of a solenoid. Make as many turns as you can, but don't make the turns too tight. The inductance will be proportional to the number of turns squared, and to the area of each turn, and inversely to the length. If you put a metal rod with high permeability inside this will increase the inductance, but don't let it stick out of the ends.
radiation
It's hard because of the chemicals that are inside of it. Though aluminum foil is not so hard it's still made out of aluminum.