Image 1 Caption: According to Hoyle---you have to click on the placeholder image to see the linked historical image.

The expression Big Bang was first used by Fred Hoyle (1915--2000) in a BBC radio program in 1949 (Wikipedia: Big Bang: Etymology). He was actually an opponent of the Big Bang theory and proponent of the steady state universe theory: see The Steady State Universe below.

Image 1 is NOT of the actual broadcast where the term Big Bang was coined, but comes from 1954.

The expression Big Bang did NOT come into general use until circa 1970 and was used only once in a publication by George Gamow (1904-1968) the primary originator of the Big Bang theory in 1946 (see Helge Kragh 2024, "How did the Big Bang get its name? Here's the real story", 1 page; Gamow 1946, Physical Review, 572--573, Expanding Universe and the Origin of the Elements).

What nowadays we call Big Bang singularity (which is the mythical time zero of the Big Bang and is a singularity in general relativity) was once called the POINT ORIGIN (Bo-85,181) before circa 1961.

The Steady State Universe:

1. Fred Hoyle (1915--2000) and in a separate scientific article by Hermann Bondi (1919--2005) and Thomas Gold (1920--2004) proposed the steady state universe in 1948 (see Wikipedia: Steady-state model: History; Bo-140ff,152ff). The three persons were actually in close interaction in developing their ideas (see Wikipedia: Steady-state model: History; Wikipedia: Thomas Gold: Steady-state theory). The steady state universe was a serious rival of Big Bang cosmology up to the early 1960s.

2. The steady state universe is an expanding universe model based on the axiom that the universe is homogeneous and isotropic and unchanging as observed on large enough spatial scales. This axiom is call perfect cosmological principle. Hoyle himself did NOT use the perfect cosmological principle as an axiom, but obtained as a result of other axioms he did assume (see Bo-152ff).

3. In any case, given the perfect cosmological principle, the steady state universe is also infinite and eternal.

   The steady state universe has a pleasing simplicity and some folks were philosophically satisfied by an infinite, eternal, unchanging universe model.

4. If you allow the universe to evolve with cosmic time, then the perfect cosmological principle is replaced by the more general ordinary cosmological principle.

   

5. Image 2 Caption: The continuous creation of matter in the steady state universe illustrated and contrasted with Big Bang cosmological model.

6. Since the universe is expanding in the steady state universe, new matter has to be continuously created out of nothing at a very low rate per unit volume that is the same everywhere. However, the largest amounts are in intergalactic space because that has the most volume.

   In steady state universe, it was assumed that new matter was just electrons, protons, and possibly neutrons (see Bo-151).

   The new matter in intergalactic space would occasionally undergo gravitational collapses to form new galaxies of interstellar medium (ISM) which would then undergo star formation, and so turn the new galaxies into ordinary observed galaxies.

   The new matter and new galaxies were supposed to keep the steady state universe looking the same on average even though expansion was acting to reduce the densities of matter and galaxies.

   Actually, yours truly thinks a steady state universe with galaxies of vastly different ages (some being infinitely old) would look rather weird. It does NOT seem that a detailed picture of the steady state universe has ever been developed, at least NOT with a post 1980 understanding of galaxy formation and evolution.

7. The new matter is actually created with kinetic energy which drives the continuous expansion of the steady state universe.

   The expansion itself is exponential expansion. So the steady state universe is a version of the de Sitter universe (1917) with the driver of expansion is the kinetic energy of the new matter instead of the cosmological constant as in the original de Sitter universe (1917).

   

8. Image 3 Caption: The cosmic scale factor for various cosmological models.

   The blue curve is for the cosmic scale factor a(t) for the de Sitter universe (1917).

   

9. Image 4 Caption: "Pursuit (1952) by Boris Anrep (1883--1969), part of a series of mosaics of the Modern Virtues in the entrance hall of the National Gallery, London. It depicts the astronomer Sir Fred Hoyle (1915--2001) as a steeplejack climbing up to the stars." (Slightly edited.)

   By the by, Fred Hoyle was also a science fiction writer. His most noted scifi novel is The Black Cloud (1957).

10. The steady state universe was a good theory: a theory does NOT have to be right to be a good theory.

    It accounted for the observations available in the 1940s and early 1950s as well as any other cosmological model then available.

11. Also, the steady state universe had falsifiability in the sense used by philosopher of science Karl Popper (1902--1994)---and it was falsified.

    In 1955, evidence from counts of radio galaxies, cosmologically near and far, suggested that there was evolution in cosmic time (see No-540--541). The discovery of quasars in 1963 (see Wikipedia: Quasar: Early observations (1960s and earlier) verified that evolution certainly happens since quasars are extinct in local/modern observable universe. The nearest quasar is in galaxy Markarian 231 at physical distance ∼ 580 Mly ≅ 190 Mpc, and so existed ∼ 580 Myr ago. Other evidence for an evolving observable universe accumulated in the 1960s. In fact, the strongly-evolving Big Bang cosmology became established as the cosmological paradigm in the 1960s and has become ever more firmly established since then.

    So by the mid 1960s the steady state universe had been falsified since its predicts NO evolution of observable universe and the observable universe does evolve. Nowadays, the steady state universe just an interesting theory in the history of cosmology.

12. Oddly enough, in unpublished work written in 1931, Albert Einstein (1879--1955) at least partially anticipated the steady state universe (see Wikipedia: Steady state theory: History; Einstein's Lost Theory Uncovered, Davide Castelvecchi, 2014feb25).

    

13. Image 5 Caption: "Some observatory buildings at the Institute of Astronomy, Cambridge of the University of Cambridge. The Northumberland Telescope is in the dome on the left. The covered structures in the foreground are mounts for portable telescopes."

    Fred Hoyle (1915--2000) worked for many years at the Institute of Astronomy, Cambridge.

1. Credit/Permission: Anonymous photographer for Desert Island Discs (1942--), 1954 / None: You will have to click on image to see Fred Hoyle (1915--2000).
   Image site: BBC: Fred Hoyle.
   Image link: Placeholder image alien_click_to_see_image.html.
   
2. Credit/Permission: © User:Artistosteles, 2022 / CC BY-SA 1.0.
   Image link: Wikimedia Commons: File:Big Bang and Steady-State Theory.png.
   
3. Credit/Permission: © User:Greek3, 2017 / CC BY-SA 4.0.
   Image link: Wikimedia Commons: File:Mplwp universe scale evolution.svg.
   
4. Credit/Permission: © Anne-Lise Heinrichs, 2008 (uploaded to Wikimedia Commons by User:Flickr upload bot, 2014) / CC BY-SA 2.0.
   Image link: Wikimedia Commons: File:Pursuit_mosaic,_National_Gallery.jpg.
   
5. Credit/Permission: © User:Cmglee, circa or before 2011 / Creative Commons CC BY-SA 3.0.
   Image linked to Wikipedia: File:Cambridge_University_Institute_of_Astronomy_observatories.jpg.