Cecil Moore wrote:

Jim Kelley wrote:
Electromagnetic waves can cancel, but rocks can't.

However, two EM waves have to exist before they can cancel.

Yes, but what about the rock? :-)

If they exist, they posses both energy and momentum.

So if I "possess" an American Express card, do I "possess" money? No.
I simply "possess" the potential to purchase something with it at a
point of sale.

73, Jim AC6XG