The first rule of analog computers is that you should not use a differentiator unless it's absolutely necessary, because it's physically a high-pass filter and amplifies high-frequency noise.

It's amusing that the same lesson also applies to digital signal processing. Differentiate a signal without filtering or interpolation gives you total garbage. The quantization noise of the ADC can make the problem even worse than analog, every code jump is a sudden change and creates a spurious spike. #electronics

Abusing a DC-DC chip designed for 60 V supply to switch up to 1000 V by putting a cascode transistor in series with its switching node. And this is in the official application note, written by nobody else than the engineer-in-chief...

Unlike computing where undefined, unspecified and implementation-specific hacks are frowned upon, in analog electronics, almost everything is permitted. The only limits are your knowledge and imagination... #electronics

MFW I realized most quantum experiments in introductory books are just lies to children, they're thought experiments at best. The literal setups as described either never work in practice, or don't really prove their results due to loopholes.

An interferometer with a single photon is the worst offender. Ordinary light sources like lamps or lasers can never work as single-photon sources. Even if you add a huge attenuator and make the light intensity lower than the energy of a single photon, there's still a non-negligible probability that it will emit multiple photons. In fact all experiments before the 1980s had this loophole. Creating true "anti-bunching" single-photon sources requires esoteric techniques. Still, this probability can only approach but not reach 0% in practical devices.

For the same reason, the BB84 quantum key distribution protocol often don't work in practice in its original form. Source or detector imperfections make the original protocol often totally broken. https://physics.unm.edu/Courses/Deutsch/Phys566F19/Lectures/Aspect%20the%20first%20single%20photons%20sources.pdf