Yes, well ultimately we'd like to understand the observable universe.

We talk about Copernicus, Einstein, Hubble, multiverses, the observable universe, the speed of light and the elements.

We are not merely legion-we rival in our numbers the stars of the observable universe in the current epoch.

A top theoretical contender is gamma-ray bursts, equally mysterious cosmic explosions that can briefly outshine everything else in the observable universe.

That's a one with 21 zeroes after it-over50 times the number of stars in the observable universe.

This was about the time the observable universe could still fit within the 87-foot sphere of the Rose Center for Earth and Space.

These clouds are trouble for the EHT astronomers, who want to peer closer than ever before at this fringe of the observable universe.

Map of Matter in the Universe: This full-sky map from the Planck mission shows matter between Earth and the edge of the observable universe.

It would take more Planck lengths to span a grain of sand than it would take grains of sand to span the observable universe.

Still, the observable Universe alone should be big enough for most people.

The whole Universe is at least 250 times as large as the observable Universe.

The observable Universe is, of course, much larger.

Per second, a single gamma-ray burst can produce as much energy as all the starlight in the observable Universe, he says.

The most redshifted light we can detect in the observable Universe suggests that light has reached us from galaxies that are 13.8 billion years old.