The universe is big, as Douglas Adams would say.
The most distant light we can see is the cosmic microwave background (CMB), which has taken more than 13 billion years to reach us. This marks the edge of the observable universe, and while you might think that means the universe is 26 billion light-years across, thanks to cosmic expansion it is now closer to 46 billion light-years across. By any measure, this is pretty darn big. But most cosmologists think the universe is much larger than our observable corner of it. That what we can see is a small part of an unimaginably vast, if not infinite creation. However, a new paper published on the arXiv preprint server argues that the observable universe is mostly all there is.
In other words, on a cosmic scale, the universe is quite small.
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