These have their place, certainly, but I'd find it hard to believe that power-consuming electronic replacements (also considering the environmental impact from raw materials and waste products, and energy used to manufacture them) are a "better" choice than a chalkboard in many cases.
A PC with a projector can last a decade in use and depending on the region may be powered by mostly or all renewables.
That's part of why it's incredibly difficult to talk about waste on industrial scales. One plant's garbage is frequently another's input. Waste is expensive, so plants will always try to reduce it to the bare minimums, and if possible make money off it, in the case of certainl classes of recyclables.
Sure but the amount of carbon you burn to get to that rock, excavate it, process it, move it, etc, etc is non-trivial. A computer and projector on 8 hours of day is a drop in a bucket to that.
In fact the cost things like PECVD or dry etching is so disproportionate compared to drilling a hole in the ground, that I'm willing to bet a computer is the equivalent of hundreds of years worth of a blackboard with chalk.
Really, I recommend anyone look into this stuff. Just to get silicon to the purity and precise structure to just start chip fabrication: https://en.wikipedia.org/wiki/Czochralski_process Imagine the whole supply chain, from smelting metal for wires and cases to plastic molding to storage, economies of scale truly are vast.
>that I'm willing to bet a computer is the equivalent of hundreds of years worth of a blackboard with chalk.
As someone who grew up near a limestone mine, I think you greatly underestimate how much work it takes to get rocks from the earth. I've seen some of the largest machines in the world working there. Its an huge operation.