That's referenced in the article -- Chaitin's constant is 'algorithmically incompressible' according to Kolmogorov complexity -- though note that this definitio

That's referenced in the article -- Chaitin's constant is 'algorithmically incompressible' according to Kolmogorov complexity -- though note that this definition means it's "assymptotically" random, but the first n bits can be approximated in finite time (there are other numbers with more strict randomness). What the article addresses is that if you're given a long string with that property you can't verify the randomness, by definition. But using the CHSH method outlined you can, assuming only some physical principles -- provided you're given a small 'seed' to start. Note that the underlying "way" that the universe generates randomness doesn't matter from a scientific standpoint -- as long as we can't predict it, you can think of it as being generated by either an enormous computer or truly random (whatever that means).