Sometimes astrophysicists distinguish between the visible universe , which includes only signals emitted since recombination-and the observable universe , which includes signals since the beginning of the cosmological expansion ( the Big Bang in traditional cosmology , the end of the inflationary epoch in modern cosmology ) .
Sometimes astrophysicists distinguish between the visible universe , which includes only signals emitted since recombination-and the observable universe , which includes signals since the beginning of the cosmological expansion ( that is , the end of the inflationary epoch in modern cosmology ) .