The critics of Ukrainian use of the mines appear to be protestors. In theory, they could also protest the Russian use, but it’d be a bit silly to picket against an invasion regardless (unless your government is the one invading).
The idea is that land mines are indiscriminate and long-lasting, so they should not be used by either side regardless of the other’s stance. They’re a bit like anti-nuclear protests, I think.
It looks like a research group found a security vulnerability that they then used to find a single common key in all of the cards made by this company. The second part here is a reasonable concern, but the article calls the vulnerability a backdoor in the beginning, which I think is fairly misleading.
Maxwell’s equations have already been rewritten into the Dirac equation. Magnetic monopoles are quantum weird and would not show up in undergrad textbooks regardless
It’s not really communication. They ‘know’ because they become part of the same wave function. The wave function of the system is
|psi1 psi2> ± |psi2 psi1>
Note that if the ± is a plus, then exchanging psi1 and psi2 yields the exact same equation. If it’s a minus, you get a negative sign out front. Electron systems have a negative sign because of the spin statistics theorem (I don’t understand that part, so you can look it up if you want—it involves field theory iirc) Now, if electrons are exactly the same (indistinguishable), then exchanging them will yield the exact same wave function, leading to
|psi1 psi2> - |psi2 psi1> = |psi2 psi1> - |psi1 psi2>
The only solution here is |psi1 psi2> - |psi2 psi1> = 0
But recall that |psi1 psi2> - |psi2 psi1> describes the system as a whole. So this system is prohibited by quantum mechanics, and there’s no way for two electrons to have indistinguishable states (be in the same place at the same time).