Big Bang by group5


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Big Bang by group5

  1. 1. The Big Bang theory is the prevailingcosmological model that explains the earlydevelopment of the Universe. According to the BigBang theory, the Universe was once in anextremely hot and dense state which expandedrapidly. This rapid expansion caused the youngUniverse to cool and resulted in its presentcontinuously expanding state. According to themost recent measurements and observations, thisoriginal state existed approximately 13.7 billionyears ago, which is considered to be the age of theUniverse and the time the Big Bang occurred.
  2. 2. The Big Bang theory developed from observations of thestructure of the Universe and from theoretical considerations. In 1912Vesto Slipher measured the first Doppler shift of a "spiral nebula"(spiral nebula is the obsolete term for spiral galaxies), and soondiscovered that almost all such nebulae were receding from Earth. Hedid not grasp the cosmological implications of this fact, and indeed atthe time it was highly controversial whether or not these nebulae were"island universes" outside our Milky Way. Ten years later, AlexanderFriedmann, a Russian cosmologist and mathematician, derived theFriedmann equations from Albert Einsteins equations of generalrelativity, showing that the Universe might be expanding in contrast tothe static Universe model advocated by Einstein at that time. In 1924,Edwin Hubbles measurement of the great distance to the nearest spiralnebulae showed that these systems were indeed other galaxies.Independently deriving Friedmanns equations in 1927, GeorgesLemaître, a Belgian physicist and Roman Catholic priest, proposed thatthe inferred recession of the nebulae was due to the expansion of theUniverse.
  3. 3. Extrapolation of the expansion of the Universe backwards intime using general relativity yields an infinite density and temperatureat a finite time in the past. This singularity signals the breakdown ofgeneral relativity. How closely we can extrapolate towards thesingularity is debated—certainly no closer than the end of the Planckepoch. This singularity is sometimes called "the Big Bang", but the termcan also refer to the early hot, dense phase itself, notes which can beconsidered the "birth" of our Universe. Based on the measurements ofthe expansion using Type Ia supernovae, measurements oftemperature fluctuations in the cosmic microwave background, andmeasurements of the correlation function of galaxies, the Universe hasa calculated age of 13.75 ± 0.11 billion years. The agreement of thesethree independent measurements strongly supports the ΛCDM modelthat describes in detail the contents of the Universe.
  4. 4. The Hubble Ultra Deep Field showcases galaxies from anancient era when the Universe was younger, denser, andwarmer according to the Big Bang theory.
  5. 5. This timeline of the Big Bang shows the sequence ofevents as predicted by the Big Bang theory, from thebeginning of time to the end of the Dark Ages. It is a logarithmic scale that shows 10 cdotlog_{10} second instead of second. For example, onemicrosecond is 10 cdot log_{10} 0.000 001 = 10 cdot (-6)= -60. To convert -30 read on the scale to second calculate10^{-frac{30}{10}} = 10^{-3} = 0.001 second = onemillisecond. On a logarithmic time scale a step lasts tentimes longer than the previous step.
  6. 6. WMAP image of the cosmic microwave background radiation
  7. 7. The cosmic microwave background spectrum measured by the FIRAS instrumenton the COBE satellite is the most-precisely measured black body spectrum in nature.[51] Thedata points and error bars on this graph are obscured by the theoretical curve.
  8. 8. This panoramic view of the entire near-infrared sky reveals the distribution of galaxies beyond the Milky Way. The galaxies are color coded by redshift.
  9. 9. The overall geometry ofthe Universe isdetermined by whetherthe Omega cosmologicalparameter is less than,equal to or greater than 1.Shown from top tobottom are a closedUniverse with positivecurvature, a hyperbolicUniverse with negativecurvature and a flatUniverse with zerocurvature.
  10. 10. A pie chart indicating the proportional composition of different energy-density components of the Universe, according to the best ΛCDM model fits –roughly 95% is in the exotic forms of dark matter and dark energy
  11. 11. This is an artists concept ofthe Universe expansion,where space (includinghypothetical non-observable portions of theUniverse) is represented ateach time by the circularsections. Note on the leftthe dramatic expansion(not to scale) occurring inthe inflationary epoch, andat the center the expansionacceleration. The scheme isdecorated with WMAPimages on the left and withthe representation of starsat the appropriate level ofdevelopment.
  12. 12. Thank you for watching our presentation! ;)GROUP 5Karolina Gajek (Poland)Roksana Zwolinska (Poland)Klaudia Zak (Poland)Joanna Mikoda (Poland)Raquel Santana Ríos (Spain)Iru Rodríguez García (Spain)Jennifer González Carballo (Spain)Jan (Germany)