Ask HN: What is something you can't grasp? - lainon
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skh
I can’t fully grasp the expansion of the universe. It seems intuitive to me
that if something expands it must be expanding in something larger. Back when
I was going to major in physics one professor told me to imagine a balloon
expanding as a way of thinking about the expansion of the universe. It didn’t
help me. A balloon can only expand since it is in a larger structure with room
to expand.

So what is the universe expanding in? If this isn’t a valid question then how
should I try to understand the universe expanding?

