Specifically, while the kugelblitz is a prediction of general relativity, quantum pair production from strong electric fields makes it infeasible in practice. Even quasars wouldn’t be bright enough, and those are far beyond the energy level of a single Dyson sphere. This doesn’t rule out primordial black holes forming at the time of the Big Bang, however.
It might still be possible to create micro black holes with particle accelerators, but how easy this is depends on some unanswered questions about physics. In theory, such an accelerator might need to be a thousand light years across at most, but this depends on achievable magnetic field strength. (Magnetars?) On the other hand, if compactified extra dimensions exist (like in string theory), the minimum required energy would be lower. One that small would evaporate almost instantly though. It’s not clear if it could be kept alive long enough to get any bigger.
Specifically, while the kugelblitz is a prediction of general relativity, quantum pair production from strong electric fields makes it infeasible in practice. Even quasars wouldn’t be bright enough, and those are far beyond the energy level of a single Dyson sphere. This doesn’t rule out primordial black holes forming at the time of the Big Bang, however.
It might still be possible to create micro black holes with particle accelerators, but how easy this is depends on some unanswered questions about physics. In theory, such an accelerator might need to be a thousand light years across at most, but this depends on achievable magnetic field strength. (Magnetars?) On the other hand, if compactified extra dimensions exist (like in string theory), the minimum required energy would be lower. One that small would evaporate almost instantly though. It’s not clear if it could be kept alive long enough to get any bigger.