1.pptx_thebigbangtheoryand theformationoflightelements
- 1. The Big Bang Theory and the Formation of Light Elements
- 2. CHEMISTRY
- 3. Cosmology is the body of science that studies the origin, evolution and eventual fate of the universe COSMOLOGY
- 4. Religious Cosmology • Religious or mythological cosmology explains the origin of universe and life based on religious beliefs of a specific tradition • The concept of creatio ex nihilo • God creating the universe as written in the book of Genesis COSMOLOGY
- 5. Physical Cosmology Physical cosmology explains the origin of universe based on scientific insights, studies and experiments • Nicolaus Copernicus and the heliocentric nature of the universe • The expanding universe through Albert Einstein’s theory of relativity • The big bang theory COSMOLOGY
- 6. The big bang theory, a cosmological model that describes how the universe started its expansion about 13.8 billion years ago, states that the universe continues to move and expand BIG BANG THEORY
- 7. 1. The universe began as a singularity or a point containing all space, time, matter and energy 2. It expanded rapidly in nothingness through a rapid yet peaceful process called inflation 3. The universe cooled down as it expanded BIG BANG THEORY
- 8. 4. A soup of matter in the form of subatomic particles was formed and nuclei of light atoms were created via nucleosynthesis or nuclear fusion between protons and neutrons 5. Electrons interacted with these nuclei to form actual, primordial atoms via the process of recombination BIG BANG THEORY
- 9. Evidences 1. Vesto Slipher and Carl Wilhelm Wirtz (1910) • Measurement of redshift • Observed that most spiral galaxies were moving away from the earth 2. Georges Lemaître (1927) • Proposed alternative idea that the universe is expanding BIG BANG THEORY
- 10. Evidences 3. Edwin Hubble (1929) • Calculated distances between the earth and several galaxies using redshift of light • Observed distant galaxies were moving away from the Earth and one another BIG BANG THEORY
- 11. Evidences 4. Robert Wilson and Arno Penzias (1965) • Discovered cosmic microwave background radiation (CMBR)—a low, steady humming noise believed to be energy remains 5. Modern astronomy (2014) • Universe is estimated to be 13.8 billion years old with 5% of its composition existing as ordinary matter BIG BANG THEORY
- 12. Big Bang Nucleosynthesis • Big bang nucleosynthesis (BBN), also known as primordial nucleosynthesis, is the process of producing light elements during the big bang expansion • It yields two stable isotopes of hydrogen, two isotopes of helium, some lithium atoms and beryllium isotopes BIG BANG THEORY
- 13. Big Bang Nucleosynthesis 1. A proton (p) and a neutron (n) may fuse together to yield a high-energy photon (γ) and an isotope of hydrogen (H) called deuterium (D or 2 H, with one p and one n) • The deuterium bottleneck can be traced to its low binding energy and eventual destruction by photons at very high temperatures • A decrease in temperature enabled deuterium to stabilize and eventually initiate the BBN cascade BIG BANG THEORY
- 14. Big Bang Nucleosynthesis 2. Two D nuclei may fuse together to form either of the following: a. The radioactive H isotope tritium (T or 3 H, with one p and two n) and one p; or b. The isotope helium-3 (He-3 or 3 He, with two p and one n) along with one n BIG BANG THEORY
- 15. Big Bang Nucleosynthesis 3. Helium-4 (He-4 or 4 He, with two p and two n) may be formed from three fusion reactions a. The fusion of one p and a T atom b. The fusion of D with T c. The fusion of D with He-3 BIG BANG THEORY
- 16. Big Bang Nucleosynthesis • He-4 has a binding energy of 28 MeV, and further fusion products were a rarity since these resulting atoms had binding energies lower than this aforementioned amount BIG BANG THEORY
- 17. Big Bang Nucleosynthesis 4. He-4 may still undergo further fusion in the presence of a T atom, yielding the lithium-7 atom (Li-7 or 7 Li, with three p and four n) and a γ • Li-7 may react with one p to produce two stable He-4 nuclei BIG BANG THEORY
- 18. Big Bang Nucleosynthesis 5. He-4 may also fuse with He-3 to yield the unstable isotope beryllium-7 (Be-7 or 7 Be, with four p and three n) along with one γ BIG BANG THEORY
- 20. • The correlation between predicted and observed cosmic abundances of H and He was the major proof of the big bang theory • Almost all available neutrons have combined with protons, forming 24% He-4 by mass • About 74% H by mass remained uncombined BIG BANG THEORY
- 21. • To verify these observations, scientists measured abundances of primordial material in unprocessed gas in some parts of the universe with no stars as well as in parts of meteorites known as chondrites that commonly fall to Earth BIG BANG THEORY
- 22. The big bang theory is a cosmological model that describes how the universe started its expansion about 13.8 billion years ago. 1 Big bang nucleosynthesis is the process of producing light elements during the big bang expansion. 2 The correlation between the predicted and observed cosmic abundances of hydrogen and helium was the major proof of the big bang theory. 3
- 23. COMPLETE THE FOLLOWING NUCLEOSYNTHESIS DIAGRAM:
- 24. WHY IS A NEUTRON RELEASED DURING THE FUSION OF TWO DEUTERIUM ATOMS?