How much (metal, refined, produced on earth) wire would you say is required to produce an air (actually vacuum, but we know air core really well so there’s math for them) core electromagnet which can generate a field capable of deflecting solar wind over the area of its pv array? In order to maintain that field strength, how much current is required? Can it be supplied by a pv array equal in area to the effective field area? How many of those are needed to cover the area of mars?
That’s-a lotta metal!
Also speaking as a person who deals with e-waste daily, it’s both by volume and mass composed of petroleum products. Fiberglass is reenforced plastic. Ics are 90% plastic by volume. Discrete components are made of petroleum distillates in a lot of cases and encased in them in even more cases!
Even if you only considered the boards as the e-waste and not the plastic cases and bodies themselves, those dont exist in a vacuum like our hypothetical electromagnets, a reduction in printer boards means fewer printers which are almost completely just plastic.
you really might not.
before there were mobile phones there was analog dtmf wired telephones. they replaced pulse dialing and allowed for all kinds of additional signalling and triggering. ring a bell, operate a relay, kick people off so you could call the president, entire automated analog switching centers, you name it.
when mobile networks came on the scene there were all sorts of additional triggers but because the (second gen? the ones that could do sms) signals were actually digital, there was a much wider array of possibilities. dtmf had a handful of frequencies it supported and if you wanted to do something more you had to basically make sure the entire network you were using could send, transport and receive those frequencies.
now imagine instead of sixteen combinations of frequencies played at the same time you have access to thousands of possible triggers. once you have simple stuff like the basic receiving of text and lighting a led or playing one of several legally distinct jingles covered, you could do do much more. and people did. there were all kinds of things pagers could do through combinations of local interface and digital communication with a cell tower, all mediated through a handful of baseband chips on the pager pcb that could have the pins for stuff they wouldn’t be used for disconnected.
but how would you make a pager set off an explosive?
well, the same way you use a casio f91w wristwatch to. you use its built in functionality (the speaker when the alarm goes off) to trigger a battery that can deliver enough electricity into a resistor to heat it up enough to make your (primary) explosive detonate.
in the case of a pager, those baseband chips have all kinds of on and off switching built in. it’s not hard to imagine that basic, out of the box functionality would include pulling a pin high when it gets “*97” or some such. now tie that pin to the base of a transistor across the positive and negative terminals of the battery and sitting against a little petn and you got yourself a remotely triggered explosive.
you wouldn’t even need a pcb.
there’s probably a lot of stuff thats incorrect in this reply. it’s late and this is off the dome.