Well, I am debating you, not M. Kaku. I always wondered why people delegate their thinking to someone else and expect we swallow it just because that someone has a "Phd" string that prefixes his name. This seems to be a pretty common tactic among creationists.
If I throw at you a list of tensorial differential equations and claim that they invalidate his reasoning, what are you going to do? Call him?
Incidentally, M.Kaku is questioning whether relativity is still valid at extreme regimes, like the ones we find at the so-called singularity (where everything becomes infinite), which is a moniker for "what we do not know". But I think all physicists question that, since physicists do not like infinities without an obvious renormalization available. When you do not know how nature behaves at certain regimes, it does not make much sense to say the relativity, or anything else, is still valid there. This is obvious.
But in general he does not seem to doubt the validitty of relativity, in general. I think he was one of the doubters of the the news of alleged superluminal neutrinos found during an experiment a few years ago. A finding that would have invalidated special relativity. Therefore, his confidence on the basic tenets of relativity seems intact.
The fact that intervals of time between two events is relative to the observer, and that there is not such a thing as objective simultaneity, are results of experiments. And are therefore accepted facts, independently from relativity breaking at the core of a black hole. Even if relativity were false, they would still be valid.
So, do you accept these facts? If not, why not?
Ciao
- viole