Sample Essay on Big Bang, Dark Matter and Inflation

Big bang nucleosynthesis refers to the process of light element formation in the early stages of the universe. The elements formed are helium-4, helium-3, beryllium-7, deuterium, tritium, and helium-7 isotopes. However, the isotopes tritium and beryllium-7 are unstable and rapidly decay to helium-3 and lithium-7 respectively. Most cosmologists believe that this process occurred between 10 minutes and 20 minutes after the big bang.The process occurred within the temperature range of 116 gigakelvin and 1.16 gigakelvin and happened in the entire visible universe. At this stage the universe consisted of very high temperatures that prevented the formation of atomic nuclear, but it existed as a soup containing protons, neutrons, photons and electrons. When protons and neutrons combined they formed atomic nuclear that were rapidly destroyed through collisions with the photons. However, as the temperature dropped, the amount of photons reduced considerably and favored the formation of these elements(“Lithium Isotope Abundances Test Big Bang Nucleosynthesis”).

Inflation refers to the exponential expansion of the universe that lasted for a very short time approximately 10-37 seconds. This process led to reduction in temperature and pressure that favored nucleosynthesis.  Hubble observed that distant galaxies were getting further away from the earth by studying their red shifts, which supports the idea that once the objects in the universewere closer together in the past. Inflation indicates that the universe during its conception consisted of very dense matter at very high temperatures.

Dark matter refers to the matter in the universe that cannot be detected using ordinary observation methods such as use of electromagnetic radiation. Its presence can only be inferred from its interaction with visible matter. Dark matter is further categorized into hot, warm and cold depending on the energy and velocity associated with the particles. Cold dark matter is believed to be the key for accounting for the mass of the universe as stars and other objects constitute only a fraction of the estimated mass. Cold dark matter refers to matter that moves at a very low speed relative to the speed of light and do not radiate, absorb or interact in anyway with energy in the electromagnetic spectrum. However, the cold dark matter interacts with gravitational field as evidenced by warping of light from far galaxies by clusters of this matter and also explains why Kepler’s laws do not apply to the revolution of galaxies(Paul).

Cold dark matter can be further divided into weakly interacting massive particles (WIMPs), axions and massive compact hollow objects (MACHOS). MACHOs are massive, non-luminous and similar to black holes and neutron stars. However, the enormous number of these objects that can be used to account for the missing mass of the universe contradicts the big bang theory. This dark matter can be detected using the gravitational lens technique proposed by Albert Einstein where the object focuses the light from other galaxies and makes them look brighter or by observing its gravitational influence on nearby objects. The mass of MACHOs can be estimated by determining the distance and duration of the lens phenomenon. On the other hand, WIMPS are hard to detect as they consist of small subatomic particles that pass through ordinary matter. Various projects have been set up to detect WIMPS by studying changes that might occur in a solid following its reaction with ordinary matter. One experiment uses the arctic ice sheet as an instrument to detect this class of dark matter.

 

Work cited

Paul, BC. “Dark Matter And Dark Energy In The Universe”. BIBECHANA 11.0 (2014): n. pag. Web.

“Lithium Isotope Abundances Test Big Bang Nucleosynthesis”. Phys. Today (2013): n. pag. Web.