Ok so the Centennial Bulb (as we quaintly call it in the present) is probably making me think more than the rest of the series, no mean feat. It already strains credibility that a single light bulb has been burning continuously for 115 years. For 15,000 years? Clearly it's had help at this point. I figured the nanos were somehow replenishing the filament by whatever incremental amount it's strained or used up or however that works. They even mention the site as being "protected", and it seems to me that the nanos would be incredibly useful in preserving monuments. ("Why are all of the buildings still the same ones," Nine considers asking at some point. Answer: nanos, the second magic bean in the story, if I'm using the term correctly.)

So anyway, if it's a protected site, you'd think the nanos would protect the bulb. Or, failing that, repair it - but if it's "gone", then any reassembly is going to come back to a severe discussion on Theseus' Ship. "The screw was still there so it was reconstructed around that." Does it still count, then, as the same bulb that's been burning since 1901? Or does this society say, "Yeah, that didn't count, and now we have the power to undo mistakes like that?“