Believe me, I know all about bottle acoustics. I spent much of the sixth century in an old sesame oil jar, corked with wax, bobbing about in the Red Sea. No one heard my hollers. In the end an old fisherman set me free, by which time I was desperate enough to grant him several wishes. I erupted in the form of a smoking giant, did a few lightning bolts, and bent to ask him his desire. Poor old boy had dropped dead of a heart attack. There should be a moral there, but for the life of me I can't see one.