mgc_mgc

In this case a glassworking lathe is needed to align and bring together the copper and glass tubes while the seal is being made.

Photons. https://en.wikipedia.org/wiki/Bremsstrahlung

Zinc-Air primary cells have about twice the energy density of Li-ion cells. https://en.wikipedia.org/wiki/Comparison_of_commercial_batte...

Depending on the circumstances, boiling in stops and starts may not be too bad: https://en.wikipedia.org/wiki/Tyndallization