While most astronomers andcosmologists today accept that the bigbang theory offers a reasonablyaccurate account of the origin of the universe, what are the problems with big bang cosmology?

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Answer 1

1. While most astronomers andcosmologists today accept that the bigbang theory offers a reasonablyaccurate account of the origin of the universe, what are the problems with big bang cosmology?

The big bang theory is farfrom perfect. One of the most striking anomalies, and theone that is most likely to generate revisions in the near future,is the existence of dark matter and dark energy. These are forms of matter and energythat can be detected but not yet understood.

Astronomers first realized that there must be much morematter than humans can see when studying the movements ofstars in galaxies. Using the laws of gravity, it is possible toestimate how fast stars should be orbiting large galaxies.The actual movements of stars suggest that there must beperhaps 20 times as much mass as astronomers can actuallydetect. Some of that mass consists of dark matter.In addition, in the late 1990s it became apparent that therate of expansion of the universe is accelerating, and mostcosmologists believe that this acceleration is driven by anew form of energy, known as dark energy, which acts asa sort of antigravity, driving things apart rather than pullingthem together.

Dark energy makes up about 70 percent of the mass ofthe universe. Because dark energy is linked to the amount ofspace that exists, this is a form of energy whose importancewill increase as the universe expands. Indeed, it seems thatthe rate of expansion of the universe began to accelerate,due to the increasing power of dark energy, about 9 billionyears after the big bang, at about the time the Earth wasformed. Dark matter accounts for another 25 percent of themass of the universe. The remaining 4 to 5 percent is madeup of atomic matter. Most atomic matter is in the form ofhydrogen and helium and only about 1 to 2 percent consistsof heavier chemical elements from carbon to uranium. Buteven most atomic matter is invisible, so less than 1 percent of the matter in the universe can actually be detected. Until the true nature of dark matter and energy isexplained, a question mark will continue to hover over theentire big bang theory.

However, astronomers and cosmologists are optimisticthat experiments such as the Large Hadron Collider(LHC) maysoon offer some answers. TheLHC has discovered what appears to be the Higgs boson.As it begins to operate at even higher energy levels, manyhope it will discover other forms of energy and matterthat can help explain what dark energy and matter reallyconsist of.