What does the field of the London Moment do as it approaches the surface of the spinning SC? A: Continue to the surface undiminished then fade away in a few penetration lengths, exactly as though it were an exterior field being applied to a stationary SC. B: Start fading away a few penetration lengths above the spinning surface so that at the surface there is no registered field. B seems unlikely (so anything to do with SCs is likely?), but it seems to be what some texts suggest. I've found all sorts of theory but no clear, concise description of the phenomena. References to authoritative observations of this, one way or the other, would be most appreciated.