Inflation and expansion of the universe

In summary, observations have shown that the universe is expanding and that objects recede at a faster speed the further we look back in space. This also means that the further we look, the further back in time we are seeing. However, the furthest we can see back in time is about 379,000 years after the big bang, when the hot plasma in the universe cooled enough for light to travel far. Prior to this point, light could not travel far due to the strong interaction with plasma. The furthest we can see using electromagnetic radiation is the Cosmic Microwave Background, which was created by the recombination event. To see further back in time, we would need to use neutrinos, but their weak interaction with matter makes it impossible
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phtdegroot
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We know from observations that the universe is expanding and that the speed of recession of celestial objects increases the further we look back in space.
However, looking further in space is also looking back in time, so does this mean that we are looking at the end of inflation ?
 
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  • #2
We can't see that far back in time, phtdegroot. The furthest we can see back is to about 379,000 years after the big bang. At this time, the hot plasma that permeated the universe reached a lower enough temperature for protons to combine with electrons to form neutral atoms. This is important because plasma interacts very strongly with EM radiation such as light, absorbing or scattering it before it can travel far. As a consequence, prior to this point in time light could not travel very far and it is impossible to see any further back in time using EM radiation. The CMB was created by this recombination event, and represents the furthest we can see at this time. To see further we could use neutrinos, except that they interact so weakly with other matter that it's essentially impossible to focus them down to a single spot like we can do with light and EM radiation.
 
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Related to Inflation and expansion of the universe

1. What is the theory of inflation and expansion of the universe?

The theory of inflation and expansion of the universe is a scientific explanation for how the universe has grown and changed over time. It suggests that the universe underwent a period of rapid expansion shortly after the Big Bang, which led to the formation of galaxies and other structures we see today.

2. How does inflation explain the flatness of the universe?

Inflation theory proposes that the rapid expansion of the universe caused it to become incredibly flat. This is because the universe expanded faster than gravity could pull matter together, resulting in a uniform and flat distribution of matter on a large scale.

3. What evidence supports the theory of inflation and expansion?

One of the main pieces of evidence for inflation and expansion is the cosmic microwave background radiation, which is a faint glow leftover from the Big Bang. This radiation is uniform and isotropic, supporting the idea that the universe underwent a rapid expansion. Additionally, observations of the large-scale structure of the universe, such as the distribution of galaxies, also support this theory.

4. Can the expansion of the universe ever slow down or reverse?

According to current theories, the expansion of the universe will continue to accelerate due to a mysterious force called dark energy. This means that the universe will not slow down or reverse its expansion, and may even expand at an increasingly faster rate in the future.

5. How does inflation and expansion of the universe relate to the Big Bang theory?

Inflation and expansion are key components of the Big Bang theory, which is the leading scientific model for the origin of the universe. The rapid expansion of the universe during the inflationary period is thought to have set the stage for the formation of the structures we see today, such as galaxies and clusters of galaxies.

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