Table of Contents
- 1 What are two popular causes of fluctuations?
- 2 How the universe was formed that led to the formation of stars and galaxies?
- 3 What happened to denser regions of the universe?
- 4 What is the connection between fluctuations in the CMB and formation of galaxies?
- 5 Why do we see large scale structures in the universe?
- 6 Why did matter clumped into stars?
- 7 How did the first galaxies appear on Earth?
- 8 How did the early universe differ from the modern universe?
- 9 Why doesn’t gravity affect the fluctuations in the early universe?
What are two popular causes of fluctuations?
Cosmologists speculate about the new physics needed to produce the primordial fluctuations that formed galaxies. Two popular ideas are: Inflation. Topological Defects.
How the universe was formed that led to the formation of stars and galaxies?
One says that galaxies were born when vast clouds of gas and dust collapsed under their own gravitational pull, allowing stars to form. The other, which has gained strength in recent years, says the young universe contained many small “lumps” of matter, which clumped together to form galaxies.
What happened to denser regions of the universe?
Regions of higher density collapsed more rapidly under gravity, eventually resulting in the large-scale, foam-like structure or “cosmic web” of voids and galaxy filaments seen today. Voids located in high-density environments are smaller than voids situated in low-density spaces of the universe.
What caused the cosmic dark ages?
But the cosmic dark ages were a time when the universe was enveloped by a fog of neutral hydrogen that trapped the light of the first stars and galaxies. The fog didn’t lift until 1 billion years after the Big Bang, when the neutral hydrogen had been reionized and once again split apart.
What are the theories of inflation?
The monetary theory of inflation asserts that money supply growth is the cause of inflation. Faster money supply growth causes faster inflation. In particular, 1\% faster money supply growth causes 1\% more inflation. With other things constant, the price level is proportional to the money supply.
What is the connection between fluctuations in the CMB and formation of galaxies?
These primordial fluctuations in the density of matter in the early Universe are the seeds of the rich network of cosmic structure – stars, galaxies, galaxy clusters – that we observe today. It is thought that the fluctuations seen in the CMB are a result of the brief period of inflation.
Why do we see large scale structures in the universe?
As time goes on (left to right), gravity pulls together matter into large scale patterns. Notice that the pattern on the right (present day) has much more clustered structure than the left-most box (early in the Universe). Also, the Universe expands with time, so every ‘box’ in the Universe is also growing in size.
Why did matter clumped into stars?
Gravity then pulled in more matter from areas of lower density and the clumps grew. This result surprised many scientists who thought that it would have taken much longer for gravity to pull enough matter together to make a star.
What happened in the dark ages of space?
The Dark Ages and large-scale structure emergence From 370,000 years until about 1 billion years. After recombination and decoupling, the universe was transparent but the clouds of hydrogen only collapsed very slowly to form stars and galaxies, so there were no new sources of light.
What happened to the density of the early universe?
The early universe was radiation dominated density of radiation exceeded density of matter. After about 50,000 years, the density of matter exceeded the density of radiation for the first time, eventually dominating the universe. Today, it appears, dark energy dominates as the matter density has fallen.
How did the first galaxies appear on Earth?
Most cosmologists believe that the galaxies that we observe today grew from the gravitational pull of small fluctuations in the nearly-uniform density of the early universe. These fluctuations leave an imprint in the cosmic microwave background radiation in the form of temperature fluctuations from point to point across the sky.
How did the early universe differ from the modern universe?
The early universe was radiation dominated density of radiation exceeded density of matter. After about 50,000 years, the density of matter exceeded the density of radiation for the first time, eventually dominating the universe.
Why doesn’t gravity affect the fluctuations in the early universe?
While gravity can enhance the tiny fluctuations seen in the early universe, it can not produce these fluctuations. Cosmologists speculate about the new physics needed to produce the primordial fluctuations that formed galaxies. Two popular ideas are: