STEADY STATE THEORY By Erin Lukacs WWK v

STEADY STATE THEORY By Erin Lukacs

WWK v The class will understand how the Steady state theory differs from the big bang theory and other theory's, where it started, and its down fall.

JESSE L. GREENSTEIN v Steady-state Universe v Hoyle, the scientist who was presented at the supports this theory, conference by compares the deathless astrophysicists Jesse L. steady-state Universe to a Greenstein and physicist river. It may appear William A. Fowler of the unchanging, but there is California Institute of plenty of movement and Technology. change under the surface.

WHERE IS STARTED v An important point of the v In the steady-state theory steady-state Universe is that the expansion comes from it does change over time. the continuous bubbling up of the element hydrogen, from empty space at a rate of one particle every cubic meter every 300, 000 years or so.

v The Steady State theory (also known as the Infinite Universe theory or continuous creation) is a model developed in 1948 by Fred Hoyle, Thomas Gold, Hermann Bondi and others as an alternative to the Big Bang theory (the standard cosmological model). In steady state views, new matter is continuously created as the universe expands, so that the perfect cosmological principle is adhered to. v The theory requires that new matter must be continuously created (mostly as hydrogen) to keep the average density of matter equal over time.

DID YOU KNOW? v The decrease in the v The matter condenses density of the universe into new galaxies that caused by its expansion is replace receded galaxies. balanced by the continuous creation of matter.

v The steady state SUPERNOVAS? astronomers stated The Big Bang theory that these large quantities of hydrogen and helium in the universe are created by supernovae. suggests that all elements were produced at the start of the universe out of nothing. Now, both theories accept that supernovae play an important role in the formation of heavy elements.

v. The Steady DOWN FALL OF THEORY A quasar is thought to be a State Theory began to fade in luminous galactic core, powered by a super-massive black hole. Quasars are so far away from us that their light has taken several billion years to reach the Earth. So, the 1960 s after the discovery of quasars are objects from the past which indicate that a few billion years ago the structure of the universe was very different from how it is today. quasars.

Drawings of an early and a later stage for two different models of an expanding universe. The left model obeys the cosmological principle, according to which the universe is homogenous and appears the same to an observer anywhere in the universe. The right model obeys the perfect cosmological principle, which adds to the cosmological principle the additional requirement that the universe be unchanged over time— new galaxies emerge continually within the expanding space.