1 Cosmology today

The figure illustrates the Standard Model of the Cosmology Timeline. In the figure, there is a point at the top. From this point, in the downward direction, a nearly vertical bar is shown. The bar has the following characteristics: The bar is symmetrical about the top of divergence; the width of the bar increases slowly from the point of divergence at first; then it increases at a much higher rate; and then increases linearly at a negligible rate for the remaining part. The timeline of the universe is labelled on the left of the bar, and the evolutionary stages of the universe are labelled on the right of the bar. The evolution of the universe is depicted within the bar using four types of matter. The topmost part, from the point of divergence to the width of the bar becoming linear, is shown in grey with random spots having lighter and darker shades of grey. This region transitions into the second region. The second region is shown as a brown gas. This region transitions into the third region. The third region is shown as a violet mass of gas. The fourth part is shown, behind the third part, near the bottom left of the bar, as a black space intermitted by white points arranged in clusters. The point of divergence is labelled ‘0’ on the left and ‘big bang’ on the right. The region at which the rate of change of the width of the universe increases is labelled ‘10 raised to the negative thirty-second power seconds’ on the left, and ‘inflation’ on the right. The bottom part of the first region is labelled ‘10 raised to the negative thirtieth power seconds’ on the left. The transition region between the first and second regions is labelled ‘1 second’ on the left, and ‘particles form’ on the right. The beginning of the second region is labelled ‘100 seconds’ on the left, and ‘nucleosynthesis’ on the right. From this marking, till the middle of the second zone, the following timelines are shown: 1 year, and 100 years. At the bottom of the second region, a white horizontal strip is shown on the left. This strip contains randomly arranged yellow, blue, and red dots. This strip is labelled ‘380,000 years’ on the left and ‘recombination or last scattering’ on the right. The top of the third region is labelled ‘dark ages’ on the right. The next marking on the left is labelled ‘200 million years’. The next marking on the right is labelled ‘first starts and galaxies form (‘first light’)’. The next marking on the left is labelled ‘1 billion years’. The next marking on the left in the fourth region is labelled ‘10 billion years’. The next marking at the bottom of the third region is labelled ‘13.8 billion years’ on the left and ‘today’ on the right. The region from the marking ‘first stars and galaxies form’ to the marking ‘today’ is labelled ‘galaxy evolution’.