STEADY STATE THEORY: HISTORY, EXPLANATION, PRESENT - ARTE - 2024

The steady state theory is a cosmological model in which the universe always looks the same, no matter where or when it is observed. This means that even in the most remote places of the universe there are planets, stars, galaxies and nebulae made with the same elements that we know and in the same proportion, although it is a fact that the universe is expanding.

Because of this, the density of the universe is estimated to decrease by just the mass of one proton per cubic kilometer per year. To compensate for this, the steady state theory postulates the existence of a continuous production of matter.

Figure 1: Image of the extreme deep field taken by the Hubble Space Telescope 13.2 billion light years away. (Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team)

It also affirms that the universe has always existed and will continue to exist forever, although as said before, it does not deny its expansion, nor the consequent separation of the galaxies, facts fully confirmed by science.

History

The steady state theory was proposed in 1946 by astronomer Fred Hoyle, mathematician and cosmologist Hermann Bondi, and astrophysicist Thomas Gold, based on an idea inspired by the 1945 horror movie Dead of night.

Earlier, Albert Einstein had formulated a cosmological principle in which he states that the universe must be "invariant under space-time translations and under rotations." In other words: it must be homogeneous and lack any preferential direction.

In 1948 Bondi and Gold added this principle as part of their theory of the steady state of the universe, stating that the density of the universe remains uniform despite its continuous and eternal expansion.

Explanation

The stationary model ensures that the universe will continue to expand forever, because there will always be sources of matter and energy that maintain it as we know it today.

In this way, new hydrogen atoms are continuously created to form nebulae that will eventually give rise to new stars and galaxies. All at the same rate with which the old galaxies move away until they become unobservable and the new galaxies being completely indistinguishable from the oldest.

How do you know that the universe is expanding? Examining the light from stars, which are composed mainly of hydrogen, which emits characteristic lines of electromagnetic emission that are like a fingerprint. This pattern is called a spectrum and can be seen in the following figure:

Figure 2. Emission spectrum of hydrogen. The red line corresponds to the wavelength of 656 nm.

Galaxies are made up of stars whose spectra are the same as those emitted by atoms in our laboratories, except for a small difference: they are shifted towards higher wavelengths, that is, towards the red due to the Doppler effect, which is an unequivocal sign of a remoteness.

Most galaxies have this redshift in their spectra. Only a few in the nearby "local group of galaxies" show a blue shift.

One of them is the Andromeda galaxy, which is approaching and with which possibly, many eons from now, the Milky Way, our own galaxy, will merge

The receding galaxies and Hubble's law

A characteristic line of the hydrogen spectrum is the one at 656 nanometers (nm). In the light of a galaxy, that same line has moved to 660 nm. Therefore it has a redshift of 660 - 656 nm = 4 nm.

On the other hand, the quotient between the wavelength shift and the wavelength at rest is equal to the quotient between the speed of the galaxy v and the speed of light (c = 300,000 km / s):

With this data:

v = 0.006c

That is, this galaxy is moving away at 0.006 times the speed of light: about 1800 km / s. Hubble's law states that the distance of a galaxy d is proportional to the speed v with which it is moving away:

The constant of proportionality is the inverse of the Hubble constant, denoted as Ho, whose value is:

This means that the galaxy in the example is at a distance of:

Present

So far, the most widely accepted cosmological model remains the Big Bang theory. However, some authors continue to formulate theories outside of it and support the steady state theory.

Researchers in favor of the steady state theory

The Hindu astrophysicist Jayant Narlikar, who worked in collaboration with one of the creators of the steady state theory, has made relatively recent publications in support of the steady state model.

Examples of them: "Creation of matter and anomalous redshift" and "Theories of radiation absorption in expanding universes", both published in 2002. These works seek alternative explanations to the Big Bang to explain the expansion of the universe and the microwave background.

The Swedish astrophysicist and inventor Johan Masreliez is another of the contemporary defenders of the theory of the steady state, by proposing the cosmic expansion to scale, an unconventional alternative theory to the Big Bang.

The Russian Academy of Sciences, in recognition of his work, published a monograph of his contributions in astrophysics in 2015.

Cosmic background radiation

In 1965 two engineers from Bell Telephone Laboratories: A. Penzias and R. Wilson, discovered background radiation that they could not remove from their directional microwave antennas.

The most curious thing is that they could not identify a source of them. The radiation remained the same in whatever direction the antenna was directed. From the radiation spectrum, the engineers determined that its temperature was 3.5 K.

Close to them and based on the Big Bang model, another group of scientists, this time astrophysicists, predicted cosmic radiation of the same temperature: 3.5 K.

Both teams came to the same conclusion completely differently and independently, without knowing about the other's work. Coincidentally, the two works were published on the same date and in the same journal.

The existence of this radiation, called cosmic background radiation, is the strongest argument against the stationary theory, because there is no way to explain it unless it is the remnants of radiation from the Big Bang.

However, advocates were quick to propose the existence of radiation sources scattered throughout the universe, which scattered their radiation with cosmic dust, although there is no evidence so far that these sources actually exist.

Arguments in favor

At the time it was proposed and with the observations available, the steady state theory was one of the most accepted by physicists and cosmologists. By then - the middle of the 20th century - there was no difference between the nearest universe and the distant one.

The first estimates based on the Big Bang theory, dated the universe to about 2 billion years, but at that time it was known that the solar system was already 5 billion years old and the Milky Way between 10 and 12 billion years old. years.

This miscalculation became a point in favor of the steady state theory, since evidently the universe could not have started after the Milky Way or the Solar System.

Current calculations based on the Big Bang estimate the age of the universe at 13.7 billion years and to date no objects have been found in the universe prior to this age.

Counterarguments

Between the 1950s and 1960s bright sources of radio frequencies were discovered: quasars and radio galaxies. These cosmic objects have only been found at very great distances, which is to say in the distant past.

Under the premises of the steady-state model, these intense sources of radio frequencies should be distributed more or less uniformly throughout the present and past universe, however the evidence shows otherwise.

On the other hand, the Big Bang model is more concrete with this observation, since quasars and radio galaxies could have formed in denser and hotter stages of the universe, later becoming galaxies.

Views of the universe

Distant panorama

The photograph in figure 1 is the extreme deep field image captured by the Hubble Space Telescope between 2003 and 2004.

It corresponds to a very small fraction less than 0.1º of the southern sky in the constellation Fornax, far from the glare of the Milky Way, in an area where normal telescopes do not capture anything.

In the photograph you can see spiral galaxies similar to our own and our close neighbors. The photograph also shows diffuse red galaxies, where star formation has ceased, as well as points that are even more distant galaxies in space and time.

The universe is estimated to be 13.7 billion years old, and the deep-field photograph shows galaxies 13.2 billion light-years away. Before Hubble, the farthest galaxies observed were 7 billion light-years away, and the picture was similar to that shown in the deep-field photograph.

The deep space image not only shows the distant universe, it also shows the past universe, because the photons that were used to build the image are 13.2 billion years old. It is therefore the image of a portion of the early universe.

Near and intermediate panorama

The local group of galaxies contains the Milky Way and neighboring Andromeda, the Triangle galaxy and some thirty others, less than 5.2 million light years away.

This means 2,500 times less distance and time than deep field galaxies. However, the appearance of the universe and the shape of its galaxies looks similar to the distant and older universe.

Figure 3: Hickson-44 group of galaxies in the constellation Leo 60 million light years away. (Credits: MASIL Imaging Team)

Figure 2 is a sample of the intermediate range of the explored universe. It is the Hickson-44 group of galaxies 60 million light-years away in the constellation Leo.

As can be seen, the appearance of the universe at distances and intermediate times is similar to that of the deep universe 220 times further away and that of the local group, five times closer.

This leads us to think that the theory of the steady state of the universe has at least an observational foundation, since the panorama of the universe at different space-time scales is very similar.

In the future it is possible that a new cosmological theory will be created with the most successful aspects of both the steady state theory and the Big Bang theory.

References

1. Bang - Crunch - Bang. Recovered from: FQXi.org
2. Britannica Online Encyclopedia. Steady state theory. Recovered from: Britannica.com
3. Neofronters. Steady state model. Recovered from: neofronteras.com
4. Wikipedia. Steady state theory. Recovered from: wikipedia.com
5. Wikipedia. Cosmological Principle. Recovered from: wikipedia.com