Why doesn't the sea sink into the seafloor?

This week, the cause of vitiligo, whether pork is linked to a sore throat, what happens to a flame in microgravity, what causes albinism, what is dark matter and why can't we see it, why doesn't the sea sink into the seabed, why is window-cleaner fatal for flies, what determines diatolic blood pressure and why are some babies born prematurely? Dr Chris takes on more top questions from the listeners of Talk Radio 702...