This is an artist's concept of our own Milky Way. In 2008, using infrared images from NASA's Spitzer Space Telescope, scientists discovered that the Milky Way's spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars.
Holographic principle suggests that the entire universe can be seen as a two-dimensional information structure "painted" on the cosmological horizon, such that the three dimensions we observe are an effective description only at macroscopic scales and at low energies. Cosmological holography has not been made mathematically precise, partly because the cosmological horizon has a finite area and grows with time.
A long tail of interstellar dust shines in the reflected light of nearby stars in this view of a nebula in the constellation Corona Australis (the southern crown). In some parts the dust accumulates to form dense molecular clouds from which it is thought young stars are born.