The chemical composition of the Universe is dominated by the hydrogen and helium produced in the Big Bang. The remaining 90 or so chemical elements are produced in stars and constitute only a few percent of the overall mass….

The universe expands no differently without dark energy The usual understanding of how the universe’s energy is distributed is that it consists of five percent normal matter, 25 percent dark matter and 70 percent dark energy.

In 2007 an international team of astronomers used Hubble to create the first three-dimensional map of the large-scale distribution of dark matter in the Universe. It was constructed by measuring the shapes of half a million galaxies observed by Hubble.

Most ordinary matter consists of hydrogen and helium located in interstellar and intergalactic space. Only about one-half of 1% of the critical density of the universe is found in stars.

Dark matter is the invisible glue that holds stars together inside a galaxy. Dark matter attracts through gravity. The new study involved observations from the Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope in Chile.

Dark matter can refer to any substance which interacts predominantly via gravity with visible matter (e.g., stars and planets). Hence in principle it need not be composed of a new type of fundamental particle but could, at least in part, be made up of standard baryonic matter, such as protons or neutrons.

“Because there is a law such as gravity, the universe can and will create itself from nothing. Spontaneous creation is the reason there is something rather than nothing, why the universe exists, why we exist,” Hawking writes. “It is not necessary to invoke God to light the blue touch paper and set the universe going.”

So particle-antiparticle pairs can be created from “nothing”, that is from no particles to two particles, but energy must be provided, so these particles can be viewed as having been created from the energy.

Linde and Vanchurin have applied some reasonable rules to calculate that the number of universes in the multiverse and have totted it up to at least 10^10^10^7.

Thus it is obvious that even in multiverse scenarios there typically exists “physics beyond the multiverse”, meaning global properties that are realized in any of the parallel universes—at least in the context of the Many Worlds Interpretation.