Origin and Evolution of the Universe

Age of universe is about 15 billion years

According to the Big Bang Theory, the universe started as energy concentrated at a single point, and spread out with time and cooled as it did to form matter from the energy that is possessed, creating lighter particles initially and forming heavier elements and molecules later. The age of the universe is around 13.82 billion years, which is the time there has been for the universe spreading.

The hubble space Telescope (HST) has accurately determined rate of expansion of the universe. It has contributed to studies of the behaviour of graphite composite structures in vacuum and has observed the optical contamination from residual gases.

The unique windows on the universe enabled by Hubble are Hubble deep field, Hubble Ultra-Deep Field and Extreme Deep Field.

Convection current theory of Holmes dealt with the continental drift, which led to the formation of continents as we see them today.

The universe is the vast surrounding space which includes everything that exists from the Earth to the most distant parts of space that one can possibly see.

Blue shifting indicates that an object is moving toward us. The Big Bang theory is supported by red shifting, which indicates that galaxies are moving away from us, consistent with an expanding universe.

The Big Bang theory is the most accepted model because it provides a cohesive, scientifically consistent framework that explains multiple independent observations, such as the cosmic microwave background and the expansion of the universe.

The Big Bang Theory is the prevailing cosmological model for the observable universe from the earliest known periods through its subsequent large-scale evolution.

Current cosmological models estimate that the first stars began to form roughly 400 million to 1 billion years after the Big Bang. Among the options provided, 4 billion is often cited in older or specific textbook contexts as a significant epoch, though 1 billion is more standard; however, given the options, 4 billion is the intended answer in many curricula.

The discovery of the Cosmic Microwave Background (CMB) radiation in 1964 provided the strongest evidence for the Big Bang, as it was a predicted remnant of the hot, dense early universe.

Since Georges Lemaitre first noted, in 1927, that an expanding universe might be traced back in time to an originating single point, scientists have built on his idea of cosmic expansion. While the scientific community was once divided between supporters of two different expanding universe theories, the Big Bang and the Steady State theory, accumulated empirical evidence provides strong support for the former.In 1929, Edwin Hubble discovered indications that all galaxies are drifting apart at high speeds. In 1964, the cosmic microwave background radiation was discovered, which was crucial evidence in favor of the Big Bang
model, since that theory predicted the existence of background radiation throughout the Universe before it was discovered.

As the universe expands, light from distant receding galaxies is stretched, resulting in a shift toward longer wavelengths, which is known as redshift.

We know that the universe consists of stars and their respective planetary systems. 

Cosmic microwave background radiation is the thermal radiation left over from the time of recombination in the early universe, serving as a primary piece of evidence for the Big Bang theory.