If you make a room’s walls and ceiling/floor electrically conductive (with paint or tin foil or wire mesh), you create a faraday cage. And as long as the gaps are small enough (proportional to the wavelength of the signal you want to block), nothing in those frequencies is getting in or out. A Faraday bag for your phone might be cheaper, though.
I think for straight 4/4 (so not felt in half time) 140 and above is definitely fast, considering the vast majority of music falls in the 110-130BPM range.
Basically an exponential function.
It is just a definition, but it’s the only definition of the complex exponential function which is well behaved and is equal to the real variable function on the real line.
Also, every identity about analytical functions on the real line also holds for the respective complex function (excluding things that require ordering). They should have probably explained it.
Linnutee in Estonian, literally “bird’s path” because of the birds migrating south for the winter using it for navigation.
I think aliexpress EMF paint has a good chance of working. All you need is some kind of conductor (usually graphite, that’s literally just pencil lead) mixed with some kind of adhesive. I’m not sure how the adhesive doesn’t stop electricity flow (maybe there’s just so much graphite it doesn’t matter), anyways you can buy graphite spray in any electronics hobby store, a paint is just that with a different consistency.