Even the roll of a die could be called non-random, since the numbers that come up are actually the result of a number of forces acting together on the die, incl

Even the roll of a die could be called non-random, since the numbers that come up are actually the result of a number of forces acting together on the die, including the force of the rollers hand, gravity, air gusts, the surface they fall on, etc. Same principle would apply to all the other methods you mentioned since there's always a definite seed value, regardless of how difficult it is for you or another observer to capture it. All the approaches you listed would result in quality pseudo-random numbers, however, a genuine random number at the source has no apparent cause or series of events leading up to it. Cesium is one such source of genuine, uninspired and uninfluenced source of randomness. Cosmic radiation is probably another although that's probably a lot harder to capture. Here's a more detailed explanation of why radiation from radioactive decay is bona fide random. https://www.symmetrymagazine.org/breaking/2009/03/30/real-random https://www.symmetrymagazine.org/breaking/2009/03/30/real-ra... https://engineering.mit.edu/engage/ask-an-engineer/can-a-computer-generate-a-truly-random-number/ https://engineering.mit.edu/engage/ask-an-engineer/can-a-com... The NeuG is best described as a high quality PRNG as are most others unless they truly capture some random, cosmic phenomena, like echoes from the big bang detectable as cosmic background radiation.. Allegedly nothing tops the big bang as a random number generator.