You could swim through the deepest voids and encounter a single hydrogen atom in an entire football field's worth of space.

The final SPIRE Dark Field image map created by combining the Blue ... However, the image is so crowded that there is almost no empty space with the faintest galaxies merging into the background ...

The Hubble Deep Field, shown here, is a patch of sky in the constellation of Ursa Major the Great Bear. It was originally chosen because it was an empty and ... from a dark sky site.

From the point of view of cosmology, the vacuum appears to have an energy density, which is sometimes called "dark energy" or the ... is permeated by a "Higgs Field" - named after physicist ...

The dark clouds of L1527 are ... and a star will be born. The Webb image above shows how material ejected from L1527's protostar has created empty cavities above and below; the glowing orange ...