The Evolution of the Universe
- The component of the material between the stars.
The space between the stars is called interstellar space. The material found between the stars is composed of lots of gas and dust. The dust is actually made of small solid particles. The gas and dust have been scientifically referred to as Nebula. There are two kinds: bright and dark nebulae. The bright nebulae glow from the energy emanating from the stars near them or from their own light. On the other hand, the dark nebulae block the light from the stars. The interstellar space can be observed by use of Telescopes, Binoculars and Spectroscope.
- How to detect planets around stars other than our Sun? How many have been found? How many exist?
There are two major ways of detecting planets around stars: Radial Velocity and Transit photometry. Radial Velocity is used in the case where a big planet whose orbit is tight is involved. The wobbling effect and the change in color of the star it orbits can be detected using the Doppler Effect. The Transit Photometry, however, is based on consistent monitoring of the brightness of a star with an aim of detecting when it becomes dim. Dimming would be an indicator of a planet going round it, as it would be picking some of the light from the star (The Economist 2013). Since 1988, about 2000 planets around stars have been found. Over one thousand of these planets exist.
- Similarities and differences between stars found in the galactic disk and those found in the halo of our galaxy
A major similarity is that both the disk and the halo are parts of the galaxy. Secondly, both of these parts inhabit old stars within them. The first difference between the two is that the galactic disk mainly contains young stars while the halo mainly has old stars. Secondly, the disk is 100,000 light years across while the halo is over 130,000 light years across. Thirdly, halo contains “dark matter” which is absent in galactic disk.
- What is modern cosmology?
Cosmology refers to the study of the evolution of the universe: its origin, current state and future (Alles 2013). It seeks to answer questions such as how old the universe is and how wide, large or deep it is. Scientists spend sleepless nights trying to get answers, which seem hard to get. There are three pillars of cosmology: The Hubble Expansion, Cosmic microwave and the Big Bang nucleosynthesis. Modern cosmology is largely focused on the Big Bang Theory of the origin of the earth.
- Compare the Solar System and the Milky Way Galaxy. Similarity, differences and the structure of the Milky Way.
One similarity is that both the Milky Way Galaxy and the Solar System are found in space. Otherwise, the first difference is that the solar system is made up of one star called the Sun and nine planets surrounding it. On the other hand, the Milky Way comprises between one hundred billion to four hundred billion stars. Secondly, the solar system is one light year in length while the Milky Way like other galaxies is normally up to 100,000 light years in length. Thirdly, the Milky Way has a black hole at the centre while the Solar system has no hole, as this is only characteristic of galaxies. Lastly, the distance between one star and the other is shorter in the Solar System than the distance between one galaxy and another, which is wider (The Economist 2013).
- Explain The Big Bang Theory and an example of an experiment that was performed by scientists to support it.
This is a theory that tries to explain the origin of the earth. It assumes that in the beginning there was nothing. Therefore, the universe was created out of nothing. The theory states that the universe was formed through a rapid expansion-taking place 13.7 billion years ago. Big Bang is explained by several theories such as Quantum theory, the gravitational theory by Isaac Newton and many others. It argues that the universe burst into formation out of a small electron in space (Landau 2014).
- What is dark energy? When was it discovered and what effect has the discovery had on our view of the universe?
Dark energy is a mysterious concept that has affected the expansion of the universe over a long period. It is believed that dark matter makes up approximately 27% of the earth. Albert Einstein was the first to discover that there was something in the empty space. The empty space was made up of virtual particles that continually formed and then disappeared (National Aeronautics and Space Administration 2015). The discovery of dark matter has enabled scientists explain the accelerating expansion of the universe. The view that the universe was slowing down has been challenged by this discovery (Biello, 2006). The term dark energy is used by scientists to express this energy, which is evident in space, yet not known to them. They are still in the “dark” about its objective and continue to seek ways of understanding it.
Alles, D. L. (2013): The Evolution of the Universe. Western Washington University.
Biello, D (2006 August, 28): What are dark matter and dark energy, and how are they affecting the universe? Scientific American Magazine. Retrieved on March 17, 2016 from www.scientificamerican,com
Landau, E. (2014). Big Bang breakthrough announced; gravitational waves detected. Cable News Network U.S Edition. Turner Broadcasting System, Inc Retrieved on March 18, 2016 from www.cnn.com
National Aeronautics and Space Administration (2015): Astrophysics: Dark Energy, Dark Matter. Retrieved on March 17, 2016 from http://www.science.nasa.gov
The Economist (2013, June 12). How do you find planets around other stars? The Economist Newspaper Limited. Retrieved on March 17, 2016 from www.economist.com