Download to read offline
More Related Content
Similar to Physical Science SHS 24.2 Expanding Universe.pptx
Physical Science SHS 24.2 Expanding Universe.pptx
- 1.
- 2. Objective explain howwe know that we live in an expanding universe, which used to be hot and is approximately 14 billion years old. 1 At the end of the lesson, you should be able to:
- 3. Learn about It! •It is the body of science that studies the origin, evolution and eventual fate of the universe. • Cosmological studies are conducted by groups of scientists across disciplines of chemistry, physics and astronomy. Cosmology
- 4. Learn about It! •Physical cosmology explains the origin of universe based on scientific insights, studies and experiments. • Nicolaus Copernicus and Isaac Newton consider the universe as static and unchanging. Their models of the universe contain celestial bodies that are fixed in place or in certain distances. Cosmology
- 5. Learn about It! •This idea was not questioned until Albert Einstein published his final theory in general relativity. • Recent models of the universe suggest that the universe is dynamic and constantly changing. Cosmology
- 6. Learn about It! •It is a cosmological model stating that the universe started its expansion about 13.8 billion years ago. • It states that at some point in the past, all matter and energy in the universe was compressed together in a dense space. • Pieces of evidence that support the theory include the occurrence of redshift, cosmic microwave background radiation, abundance of light elements. Big Bang Theory
- 7. Learn about It! •1910s - Vesto Slipher and Carl Wilhelm Wirtz measured the wavelengths of light form spiral nebulae, which are interstellar dust and ionized gases. • They discovered that the light from the nebulae increased in wavelength (doppler shift). Big Bang Theory Vesto Slipher (1875-1969) Carl Wilhelm Wirtz (1876-1939)
- 8. Learn about It! Dopplershift or doppler effect • It explains that when an object gets closer to Earth, its light waves are compressed into shorter wavelengths (blueshifted). • When an object moves away from Earth, its light waves are stretched into longer wavelengths (redshifted). • Slipher and Wirtz concluded that redshift is a result of the expansion of the universe. Big Bang Theory
- 9. Learn about It! BigBang Theory • Suppose you are moving to the left with this arrowhead. • Light emitted from the galaxies moving toward you would be compressed. • This would make the wavelength shorted and the light bluer. Doppler shift
- 10. Learn about It! BigBang Theory • On Earth, galaxies are perceived to be moving away from the observer. • This would make the light from these galaxies stretched, with longer wavelengths and the light redder. Doppler shift
- 11. Learn about It! •1927 - Georges Lemaître proposed that the universe started as a single point that continuously expanded. • 1929 - Edwin Hubble used the redshift of light from galaxies to calculate the velocities and distances of these galaxies from Earth. He discovered that they were moving away from Earth and from Big Bang Theory Edwin Hubble
- 12. Learn about It! •1965 - Robert Wilson and Arno Penzias discovered a low, steady “hum” from their Holmdel Horn antenna. They concluded that the noise is cosmic background radiation, the remains of energy created after the big bang expansion. Big Bang Theory
- 13. Learn about It! BigBang Theory Cosmic Microwave Background temperature fluctuations
- 14. Learn about It! •According to the theory, the universe began as a point called singularity. • It is a hot, dense point containing all space, time, matter and energy. • In the nothingness, the singularity expanded rapidly in a process known as inflation. • Energy started expanding after and created matter and antimatter. • Some of these pairs cancel each other in process known as annihilation which brings back energy. The Big Bang Theory
- 15. Learn about It! TheBig Bang Theory
- 16. Learn about It! •As the universe expanded, it cooled down. • Matter in the form of proton, neutron, electron and photon are scattered in a highly energetic soup called the plasma soup. • This is where nuclei of light atoms start to form via nucleosynthesis or nuclear fission between protons and neutrons. • Electrons started to mingle with these nuclei in a primordial chemical process known as recombination. The Big Bang Theory
- 17. Learn about It! •These particles (atoms) continued moving in space until gravity acted on these particles and collapse them to form celestial bodies such as stars and galaxies. • Universe continues to expand until today. • The abundance of light elements supports the big bang theory. • It predicts that the universe is composed of 73% hydrogen and 25% helium by mass. The Big Bang Theory
- 18. Learn about It! •Using the rate at which the universe is expanding, scientists can work backward and infer that during the big bang, the universe had an infinite density and temperature. Insights from The Big Bang Theory
- 19. Learn about It! •NASA scientists proposed than in the first second after the universe began, the temperature was 5.5 billion degree Celsius. • As space expanded, the universe cooled, and matter began to form. • During the first 3 minutes of the universe, light nuclei were formed. • These nuclei include deuterium, an isotope of hydrogen and helium. Insights from The Big Bang Theory
- 20. Learn about It! •The Earth and other celestial bodies in the Milky Way are also moving away from other galaxies. • All objects in the universe are moving away from each other at the rate calculated by Hubble. • This means that the universe has no center and is expanding in all directions. Insights from The Big Bang Theory The Milky Way Galaxy
- 21. Learn about It! MultiverseModel • In this model, different universes coexist. • This suggests that during the first big push of inflation, different part of space-time grew at different rates. • These different universes probably have different laws of physics. Insights from The Big Bang Theory
- 22. Key Points Cosmology isthe body of science that studies the origin, evolution and eventual fate of the universe. Physical cosmology explains the origin of universe based on scientific insights, studies and experiments. 1 2 The big bang theory is a cosmological model stating that the universe started its expansion about 13.8 billion years ago. 3
- 23. Key Points Some physicistspropose the multiverse model, which believes that different universes coexist. 4
- 24. Check Your Understanding Arrangethe following events chronologically according to the stages of the big bang. Place a number to indicate their chronological order. Energy expanded, creating matter and antimatter. The singularity expanded rapidly. The universe cooled down as it continues to expand.
- 25. Check Your Understanding Arrangethe following events chronologically according to the stages of the big bang. Place a number to indicate their chronological order. During expansion, matter and antimatter often react to form more energy. Space expanded. The universe began as a single point. Nucleosynthesis begin and substances start to form.
- 26. Check Your Understanding Arrangethe following events chronologically according to the stages of the big bang. Place a number to indicate their chronological order. Ultimately, celestial bodies such as planets and stars were created.
- 27. Challenge Yourself 1. Isthe universe really expanding? Cite major pieces of evidence to prove your point. 2. Why do you think cooling (upon expansion) is a prerequisite before nucleosynthesis can occur?
- 28. Photo Credits ● Slide18: This file, ESO/Y. Beletsky, by ESO-VLT-Laser-phot-33a-07 is licensed under CC BY 4.0 via Wikimedia Commons.
- 29. Bibliography Choi , Charles,“Our Expanding Universe: Age, History & Other Facts.” Accessed October 10, 2016. http://www.space.com/52-the-expanding-universe-from-the-big-bang-to-toda y.htm. Hurd, D. et al. 1988. Physical Science. Englewood Cliffs, NJ: Prentice Hall. Kaufmann, William J., III. 1979. Galaxies and Quasars. San Francisco, CA: W. H. Freeman and Company. Pope, Damian. N.d. The Global Positioning System. Ontario, Canada: Perimeter Institute for Theoretical Physics. Trinh, Xuan Thuan. 1993. The Birth of the Universe: The Big Bang and After. New York: Harry N. Abrams, Inc. Zitzwitz, Paul W. et al. 1995. Physics, Principles, and Problems. New York: McGraw-Hill