Cosmology Is a Branch of Science - Essay Example

Cosmology is a branch of science that involves studying the origin, and the evolution of the fate of the entire universe.
Radial Velocity
Radial velocity = change in wavelength / constant wavelength * speed of light
Galaxy 1 Radial Velocity = (8204-6563)/6563angstrome*300,000,000m/s
= 0.25*300,000,000

Galaxy 2 Radial Velocity = (6549-6563) / 6563angstrome*300,000,000m/s
= -0.0021332*300,000,000
= -639,951.24 m/s
Dark Energy in the Universe
In the field of astronomy or physical cosmology; dark energy involves the hypothetical type of energy that permeates space and it tends to increase the rate of expansion of the universe. The dark energy hypothesis explains the observations made in the 1990s; indicating the expansion of the universe at a high or accelerating rate (Schechner 39). According to the standard cosmology model; the universe comprises 68.3% dark energy, 4.9% ordinary matter, and 26.8% dark matter. Two proposals are in place to illustrate the types of dark energy: cosmological constant which explains a stable energy density in the universe; and scalar fields such as moduli, which shows varying energy density in space or time.
Matters or issues concerning dark energy are normally speculative. The evidence for the existence of dark energy arises from three major independent sources. Therefore, these sources lead us to our three major hypotheses on dark energy: distance measurements through the redshift, explaining the universe has expanded during its last half-life; the theoretical requirements for extra energy type that does not matter and dark matter, to form the observationally flat universe, and it can be identified through the large scale measurement of wave patterns with mass density. Dark energy is believed to be homogeneous and not very dense; it interacts with other universal forces; apart from gravitational force.
Structure Formation Theories
These theories hypothesize the formation of galaxies or cluster of galaxies; the Cold Dark Matter aspect of cosmology describes that clustering and also merging processes enables galaxies to gain mass and determine shape and structure. One theory explains the ‘top down’ galaxies formation aspect. The disk galaxies are created through the monolithic collapse of the large gas cloud. In the process of cloud collapse; gas settles in a highly rotating disk. This explanation is very simple, but no longer accepted (Schechner 297). The bottom-up galaxy formation theory demonstrates that galaxies are formed through coalescing involving smaller progenitors; smaller particles merge and form larger or big particles. The dark matter halos cluster during the bottom-up process.

These sedimentary rocks have sediments which are; pre-existing rock particles like sand or silt; or mineral precipitates. Through the cementation process, over time, the particles form rocks. The oldest rocks form the bottom layer, and the youngest form the top layer rocks. Using reasonable estimates; the formation of the 3500 feet Grand Canyon, took millions of years.
Conclusion
Astronomy involves a natural science that deals with studying celestial objects like galaxies, planets, and stars; and also the evolution, physics, and chemistry of the objects. Read More