There are four parameters that govern the universe expansion. First, the energy density of relativistic particles mostly is that of Cosmic Microwave Background photons. This quickly falls as the space scale-factor grows so contributes to the expansion very little. … Continue reading

# Tag Archives: expansion of the universe

The zero-zero component of the Einstein’s equations for gravity with the metric of the expending universe is called the Friedman equation. We use this differential equation to calculate the behavior of the expending space. The equation includes two unknown functions … Continue reading

How electrons began to remain in orbits In the early hot universe, free electrons were being captured by protons, forming hydrogen atoms. The photons, emitted in this process called recombination, took away the difference between the summary mass of free … Continue reading

Increasing the visible size keeping the same amount of light emitted When we look at a distant source of light that spreads in all directions, we see only a portion of the photons emitted by it. As the distance from … Continue reading

How the decay of particles overtook that of antiparticles… It is observed that the number of baryons in the universe (protons and neutrons) exceeds the number of antibaryons at least ten thousand times. Such an asymmetry could arise in the … Continue reading

On changes in the rate of expansion of space In the first moments after the Big Bang, stretching the space of the universe occurred maximally rapidly, and the distance between the points grew from those microscopic to, possibly, exceeding the … Continue reading

The expansion rate of the universe is governed by three major factors: its matter density, the curvature of the three-dimensional space and the density of invisible energy called dark energy of unknown nature. With the expansion, the density of … Continue reading

On the steady increase in all distances… After the Big Bang which occurred about fourteen billion years ago, space is expanding. It is possible to visually imagine the expansion looking as a figure drawn on the surface of a balloon … Continue reading

Changing the spectrum of light towards red as the distance from an observer There are astronomical observations showing that the rate of receding of galaxies from each other is approximately proportional to the distance between them. This law, named after … Continue reading

Variations in the rate of expansion depending on the predominant type of energy The equation written by Alexander Friedman on the basis of Einstein’s theory of gravity predicts the expansion of the universe dependent on density of the energy filling … Continue reading

On the stunning results of elementary particle physics and cosmology Modern knowledge of the microcosm and the cosmos is still far from perfect. For example, we can not describe in detail the strong interactions of elementary particles, or explain the … Continue reading