Non-standard cosmology: Encyclopedia II - Non-standard cosmology - Non-standard versus standard

Non-standard cosmology - Non-standard versus standard

Non-standard cosmologies are usually not considered by physicists, because the essentials of the big bang theory have been confirmed by a wide enough range of complementary observations that they believe there is little chance of the theory being replaced in its essentials. A well known letter by advocates of non-standard cosmology has affirmed this: "today, virtually all financial and experimental resources in cosmology are devoted to big bang studies." ^[1] Moreover, the astronomy and physics communities argue that non-standard cosmologies have not come close to reproducing the range of successes of the big bang model.

Halton Arp, one of the most famous of these astronomers, is an observational astronomer, as such his arguments do not constitute an alternative cosmological model; rather, he maintains that they are a refutation of the Big Bang, and invites theoretical astrophysicists to join him in working out alternative explanations.

Some ideas in non-standard cosmology, such as the steady-state theory of Hoyle, Gold and Bondi, the ambiplasma model of Alfven and the tired light model of Zwicky are largely of historical interest, although they may retain a few supporters. While they were once considered serious competitors to the big bang model, the discovery of the cosmic microwave background radiation, and in particular its black-body spectrum, has led most physicists to reject them and conclude that the observational evidence now strongly favors the big bang.

Today, non-standard cosmologies are generally promoted by a few independent researchers and a larger number of amateurs who disagree with some of the basic tenets of the big bang model. Largely because of the disparate nature of their work, there is not a single non-standard cosmology. Within the category are many different ideas and models which frequently contradict each other.

Non-standard cosmologies are different from cosmologies which accept the basic tenets of the big bang cosmology, while modifying parts of the concordance ΛCDM model. Such theories include alternative models of dark energy, such as quintessence, phantom energy and some ideas in brane cosmology; alternative models of dark matter, such as modified Newtonian dynamics; alternatives or extensions to inflation such as chaotic inflation and the ekpyrotic model; and proposals to supplement the universe with a first cause, such as the Hartle-Hawking boundary condition, the cyclic model, and the string landscape. There is no consensus about these ideas amongst cosmologists, but they are nonetheless active fields of academic inquiry.

Adapted from the Wikipedia article "Non-standard versus standard", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki