We used to have to separate our glass by color for recycling. Now it all goes in one bin and gets smashed together, so sorting post-pickup seems impossible. Why doesn't it matter anymore that all the glass is mixed? Is glass recycling a hoax?

—Al

Like most of my readers, Al, you are clearly a huge nerd. Mind you, I'm right there with you, but if either of us spent as much time, say, talking to girls as we do geeking out over Bureau of Environmental Services white papers on solid-waste policy, we probably wouldn't be having this conversation.

Still, Portland is nothing if not a wonk's paradise, and, as it turns out, the answer to your query is (no offense) more interesting than the question.

For starters, you probably think Oregon's curbside glass recycling is all slated to become new bottles, windows, bongs and so forth. In fact, much of it is destined for less glamorous uses (not that being a mayonnaise jar is the height of glamour) like fiberglass, or as construction aggregate for use in roadbeds.

Some of this low-grade glass mix also winds up as a drainage-friendly substitute for gravel under landfills—and if there's anything less glamorous than substitute gravel, I don't want to know about it.

That said, Al, it's the future now, and your out-of-date belief that a big pile of color-mixed broken glass can't be sorted out by technology is so touchingly naive that I can practically hear Siri snickering.

While it's admittedly not always cost-effective to use them, machines called optical sorters now exist that use puffs of air to knock glass pieces as small as three-eighths of an inch into the appropriate bin—all with a degree of precision that could reclaim the corn from your stool. Though, of course, we all hope it doesn't come to that.