Alicornutopia

Yes.

What if one of twins is stillborn, does the surviving twin still count as a twin? How long would the sibling need to survive in the womb to count? Would Elvis get powers? (His twin died before he was born.)

If "birth" is a relevant threshold for any of the things, does C-section have effects?

So… not sure if this should go in the general Incandescence discussion or here, but… why was Forks safe while Phoenix wasn’t? Forks is closer to Yellowstone than Phoenix is (I checked because they seemed about the same distance away). I hope i’m missing something so that this isn’t a big error.

I haven't checked the actual locations of those two places, but if you look at the map of the mentioned fallout zone on Wikipedia, it's almost entirely to the south and east of the volcano in question - something to do with weather patterns, probably, and/or the volcano being on the eastern side of the relevant mountain range (not sure, haven't checked).

ETA: Map, wikipedia article.

… Huh. Interesting, I’d never seen that map before, I figured the danger zone would be a roughly circular area centered on Yellowstone. Very good to know that it wasn’t an error.

I'm going to say stillbirths don't count, but C-section delivery before a nonviable sibling is technically dead will still let the living sibling(s) count as twins.

I looked up the supervolcano before determining what was going to get Pompeii'd and picked an existing tuff formation's area as a rule of thumb.

Uterine replicators? XD

So, my knowledge of supervolcanoes comes mostly from some NatGeo show I watched many years ago, but...I'm pretty sure the need to evacuate people doesn't stop as soon as the eruption actually happens. Everyone in the radius of the pyroclastic flow, yes, they're dead as soon as it hits them. Maybe our heroines were a bit farther from that, and that's why they could keep evacuating people for a few minutes before everyone there died. But most people in the outer ring of what will become the uninhabitable zone, they are most at risk of being buried alive in ash, like the citizens of Pompeii. Is there an in-story explanation for why our heroines' evacuation efforts aren't continuing for a few weeks after the eruption?

Anti-ash magic.

I am the only one that is thinking about fictional and real twins ins this setting? Ranging from the weasley twins to the olsen?