Expansion of the Universe.

Aayushi Vaish
3 min readFeb 9, 2021

Once you can accept the universe as matter expanding into nothing that is something, wearing stripes with plaid comes easy.

Albert Einstein.

Expansion of the Universe

Man is a particle of the Universe, possessing a certain range of consciousness corresponding to the era to which he belongs. People have always tried to explain the causes of various phenomena in the surrounding space, as well as the cause of the emergence of the word itself, which is called the Universe in our time. At the present stage of development of consciousness, a picture of the world emerged from the primary singularity(a special state of matter). According to the concept generally accepted in cosmology, the Universe arose as a result of the Big Bang and is still expanding. This point of view was confirmed in the first half of the last century.

The theory of a non-stationary universe, proposed by the soviet mathematician Friedman and observational data obtained by Hubble, found that distant galaxies scatter at speeds proportional to the distance from the observer, where the proportionality coefficient is the Hubble constant. Einstein argued from the start that the universe must be stationary. Friedman, who entered into a dispute with him, on the basis of field equations (Einstein’s equations) constructed a whole class of homogeneous isotropic models, among which expanding, contracting, and stationary models were theoretically possible. For simplicity, Friedman assumed that the space of the universe is homogeneous (equality of all points) and isotropic(equality of all directions). Since the results of Hubble’s observations of galaxies indicated their dispersal at a speed proportional to the distance from the observer, scientists concluded that this expansion was the result of the initial explosion of the singularity (Big Bang). Can this concept be considered the final version of the theory of the origin of the universe?

Schwarzschild Radius

It is a stumbling block on the path of development of cosmology. The fact that in all the models time flows uniformly as in Special Theory of Relativity, which does not consider the presence of gravity. The gravitational field affects the rate of flow of the observed time. This is shown by calculations in the framework of a stationary gravitational field created by a distant mass (Schwarzschild space-time), which is used to calculate the motion of the planets of the solar system. In particular, these calculations made it possible to detect the displacement of the perihelion of mercury as the planet closest to the Sun, caused by the movement of the Sun.

The observed accelerated recession of distant galaxies is explained by cosmologists by the effect of attraction to the event horizon. In relativistic physics, the event horizon defined as the surface of a Black Hole where time stops. In static ( non-rotating, non-deforming) Schwarzschild space-time, the observer is outside the attracting Black Hole. It is possible to study the role of time as a physical factor characterizing the life of the universe as a continuous process of transforming the energy of future time into the energy of the past, and the sequence of events is the membrane between them.

Considering what we already know about the universe, we know that it is expanding for sure as suggested by the red shift in the spectrum of distant stars and galaxies, but it is quite debatable that rate of expansion might not be constant there are some certain factors indeed, Gravitational waves can also cause a sudden push to the expansion. Hence, once again we realize that when it comes to our understanding of the universe we have barely scratched the surface.

Somewhere, something incredible is waiting to be known~Carl Sagan



Aayushi Vaish

An Explorer of the Infinite Multiverse . MS - Physics , Northeastern University.