"Greg \(Strider\) Moore" wrote:

New technologies will not make aluminum or plastic cheaper.

So what? They don't need to be cheaper. People literally buy millions of
items made out of aluminum and plastic every day and throw them out, the
material is so cheap.

The amount of aluminum in a soda can has decreased dramatically over
time. I remember seeing an article on can engineering in SciAm twenty
or so years ago. It's probably halfed again since then.

Cars once had frames under the body. Now, carefully shaped bodies
serve the purpose that once required a frame.

New technologies can dramatically reduce the amount of aluminum or
plastic that you require to do something.

You can overdo it. My mother believed in bulk purchasing and in
having suitable treats on hand when the grandkids arrived. When
preparing the estate, we discovered a five foot stack of soda in one
of the closets. One flat (24 cans) of Costco "Simply" cola had
pinhole-ruptured almost all of the cans, but had leaked slowly enough
that nothing sprayed and nothing escaped the cardboard flat that the
cans were sitting on. The white carpet under the dark brown leaks was
untouched. All of the plastic two-litre bottles had lost their
pressurization - the CO2 having presumably leaked past the caps in the
time since purchase. (She was in various forms of care for about a
year before the end, and we held the house off the market for another
five months for price-cycle reasons. I don't know how long the soda
was there before she went into care.)

--
We are geeks. Resistance is voltage over current.