"What this new mode implies is that up to one-half of the atoms around usincluding in the solar system, on Earth and in each one of uscomes not from our own galaxy but from other galaxies, up to one million light years away,"
We can probably say that some (or all?) of the hydrogen in our bodies was formed shortly after the Big Bang.
Because they weren't a part of another galaxy yet?
Why the one million light year boundary?
When I read the article, I was wondering how far back in time this went, and what that meant for the size of the Universe at that time compared to the size it is now - the galaxy were closer to each other back in the day.
Maybe that boundary has something to do with the expansion, and how far apart they were back in the day, and whether or not we'd expect that growing distance to be something that couldn't be surpassed.
I dunno, that's just me thinking out loud.