Speaking of cosmologists, there have been famous cosmologists roaming our earth and two of the more important cosmologists were Edwin Hubble and Stephen Hawking. Edwin Hubble, who at age 30, had an undergraduate degree in astronomy and mathematics, a legal degree as a Rhodes scholar, followed by a PhD in astronomy (Reference 3). Edwin Powell Hubble is famous for determining that there are other galaxies in the Universe beyond the Milky Way, and for observing that the universe is expanding at a constant rate. Stephen Hawking was born on the 300th Anniversary of Galileo’s death. In 1988, Hawking wrote A Brief History of Time: From the Big Bang to Black Holes, explaining the evolution of his thinking about the cosmos. It became a best seller of long standing and established his reputation as an accessible genius (Stephen Hawking).
The universe has been in existence for many millions of years, around 13.7 billion years because of the beginning of the universe can be expressed in terms of the Big Bang Theory and since this theory states that the universe started 13.7 billion years ago. The number of years continues to rise, but what impact does the estimated age have on the Earth’s development. If the age of the universe is increasing, then the Earth will be having some devastating consequences but not any time soon. The sun would eventually die turning into a white dwarf and this emits very little sunlight and this can affect the development of the Earth for living organisms. It is predicted that a big crunch could happen, which basically means that the gravitational pull will get so strong that the universe will cave in and create a black hole. Our magnetic field is also decaying and it will eventually die which means that our compasses and other electronic devices wouldn’t work. So the age of the universe has a dramatic impact on the Earth’s development.
When exploring space, there is an infinite of stuff out in space and something we do know about space are pulsars. A pulsar is a neutron star, which releases beams of radiation that sweep through the earth's line of sight. Like a black hole, it is an endpoint to cosmological evolution. The, “pulses,” of high-energy radiation we see from a pulsar are due to a misalignment of the neutron star's rotation axis and its magnetic axis (Reference 4). Pulsars pulse because the rotation of the neutron star causes the radiation generated within the magnetic field to sweep in and out of our line of sight with a regular period. Wavelengths from Pulsars give scientists important clues to how the radiation is created. Black holes are similar to Pulsars but they are quite different because they both are very unique objects.
Black holes have always had the reputation to be one of the “most talked about topics” in Cosmology. Black holes are imaginary entities predicted by the equations of general relativity. A black hole is formed when a star of undergoes a gravitational cave in, with most or all of its mass packed together into a satisfactorily small area of space, causing endless space-time curvature at that point. Such a massive space-time curvature allows nothing, not even light, escaping from its borders (Black Holes). Black holes have never been directly observed or seen but though predictions, their predictions have matched observations.
Another feature that has not been observed, but has observations to prove it, is the Inflationary Model (Reference 5). This modified version of the Big Bang theory states that the when the universe was only about 10-35 seconds old, the expansion of space-time took place at a greater accelerated pace. The huge inflation of space was made by the energy released from the separation of two forces. For around one hundred million trillion trillionth of a second, the universe grew many times faster than the speed of light, taking it from a size incredibly small, even smaller than an atomic nucleus to about the size of grapefruit (Inflationary Theory). In the process, tiny regions of the early universe were inflated to become larger than the observable universe.
Matter that can't be identified directly, but whose existence can be based on the how objects, such as stars and galaxies, move is called Dark matter. Within a galaxy like the Milky Way, the stars move as if large quantities of dark matter exist in a vast radiance that surrounds the galaxy's disk. Likewise, within clusters of galaxies, the individual galaxies move as if many more matter is present than that visible in the form of stars and gas and dust. There is currently much ongoing research by scientists attempting to discover exactly what this dark matter is, how much there is, and what effect it may have on the future of the Universe as a whole. This is why the cosmologists study Dark Matter.
The expansion of the universe is one of the questions, which cosmologists are trying to get an answer to. The galaxies we see in all directions are moving away from the Earth, as evidenced by their red shifts. The building up of methods for measuring distance to stars and galaxies led Edwin Hubble to the fact that the red shift (collapse speed) is proportional to distance. The fact that we see all other galaxies moving away from us does not imply that we are the center of the universe. All galaxies will see all other stars moving away from them in an expanding universe. Since the action of gravity works against the expansion, then if the density were large enough, the expansion would stop and the universe would collapse in a “big crunch”. This is called a closed universe. If the density were small enough, the expansion would continue forever. This is just short outline of the expansion of the Universe.
Cosmology is a very interesting topic and it is continued to be researched on using telescopes and other ways by the increase in technology. It is important to study cosmology because we can tell a lot about the creation of the universe and this will help us solve problems like if the Big Crunch or Black hole were to happen. It is also important to study cosmology because then we as human beings will be more educated on the topic of cosmology. Stephen Hawking once said, “My goal is simple. It is complete understanding of the universe, why it is as it is and why it exists at all.”
Works Cited
The Big Bang Theory. Big Bang. Windows Team. 2 June 2008 <http://www.windows.ucar.edu/tour/link=/sun/Solar_interior/Nuclear_Reactions/Neutrinos/big_bang.html&edu=elem>.
Edwin Hubble. Photographs of Edwin Hubble. The Association of Universities for Research in Astronomy. 2 June 2008 <http://opostaff.stsci.edu/~levay/presres/ehubble/>.
The Expansion of the Universe. Weird. CondéNet. 2 June 2008 <http://www.wired.com/techbiz/media/news/2006/03/70425>.
The Hubble Telescope. New Hubble Telescope Mission. WordPress Entries (RSS). 2 June 2008 <http://www.focks.com/science-technology/new-hubble-telescope-mission/>.
"Inflationary Model." National Aeronautics and Space Administration. 2008. NASA. 2 May 2008 <http://map.gsfc.nasa.gov/universe/bb_cosmo_infl.html>.
Pulsars. Pulsars. I.P Board. 2 June 2008 <http://maniacmuslim.com/forums/index.php?showtopic=9775&pid=919336&st=0&#entry919336>.
"Stephen Hawking." www.hawking.org.uk. 2007. Random House Children's Book. 2 June 2008 <http://www.hawking.org.uk/home/hindex.html>.
References
Reference 1: The Hubble Telescope
Reference 2: The Big Bang Theory
Reference 3: Edwin Hubble
Reference 4: Pulsars
Reference 5: Inflationary Model
Reference 6: The Expansion of the Universe
