Lately I visited a 3T NMR machine (subject to a research project). It got me thinking about maxiums. I know the maximum magnetic fields we have observed are quite a lot stronger than that (field strenghts on some stars), and there seems to be a theoretical maximum value for magnetic fields although the exact value can be disputed.
But, now for the questions: what is the maximum gravity field or value we have observed or possibly calculated? And is there a theoretical maximum?