Origin of the Universe

701 views
613 views

Published on

Published in: Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
701
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
43
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Origin of the Universe

  1. 1. Matter UnitMatter Unit Learning Goal #1: RecognizeLearning Goal #1: Recognize the origin and distribution ofthe origin and distribution of elements in the universe.elements in the universe.
  2. 2. Edwin HubbleEdwin Hubble  First to realize that galaxiesFirst to realize that galaxies lie outside the Milky Way …lie outside the Milky Way …  …… by measuring their distancesby measuring their distances using Cepheid variables asusing Cepheid variables as ‘standard candles’‘standard candles’ Edwin P. Hubble (1889-1953) was trained as a lawyer, before boredom made him turn to astronomy instead Cepheid variables oscillate in brightness with a regular period that depends on their luminosity. By measuring this period, they can be used as standard candles.
  3. 3. Cosmic SpeedometerCosmic Speedometer  When a galaxy is receding, lightWhen a galaxy is receding, light waves travelling to us are red-waves travelling to us are red- shiftedshifted  Hubble measured the spectrumHubble measured the spectrum of these galaxies and found theof these galaxies and found the spectral lines to be red-shiftedspectral lines to be red-shifted o The faster the recession, the greater the red-shift
  4. 4. Doppler EffectDoppler Effect  Doppler EffectDoppler Effect is the shift in frequency andis the shift in frequency and wavelength of waves which results from a sourcewavelength of waves which results from a source moving with respect to the medium, a receivermoving with respect to the medium, a receiver moving with respect to the medium, or even amoving with respect to the medium, or even a moving medium.moving medium.
  5. 5. Expansion of the UniverseExpansion of the Universe … ‘winding’ backwards, the universe must have had a beginning
  6. 6. Georges Lemaître (1894-1966) was a Belgian Catholic priest who was fond of saying there is no conflict between science and religion Georges LemaîtreGeorges Lemaître  Proposed that the universe began with theProposed that the universe began with the explosion of a ‘primeval atom’explosion of a ‘primeval atom’  His model was improved by George GamowHis model was improved by George Gamow and others, who proposed that elements wereand others, who proposed that elements were forged during this hot and dense stageforged during this hot and dense stage  Known as the Big Bang theory today; coinedKnown as the Big Bang theory today; coined by Fred Hoyle who proposed a rival theory ...by Fred Hoyle who proposed a rival theory ...
  7. 7. Steady State ModelSteady State Model  Universe is expanding, but maintainsUniverse is expanding, but maintains a constant average densitya constant average density  Matter is continually being created inMatter is continually being created in the voids to form new stars, galaxiesthe voids to form new stars, galaxies  Universe has no beginning and no endUniverse has no beginning and no end  But disproved with the discovery of …But disproved with the discovery of …
  8. 8. Cosmic MicrowaveCosmic Microwave Background (CMB)Background (CMB)  Background radiation from the sky that isBackground radiation from the sky that is isotropic (same strength in all directions)isotropic (same strength in all directions)  Corresponds to a temperatureCorresponds to a temperature of just 2.7 Kelvinsof just 2.7 Kelvins  Identified as the radiation leftIdentified as the radiation left over from the Big Bang explosionover from the Big Bang explosion Arno Penzias (right) and Robert Wilson of Bell Laboratories, next to the horn antenna with which they discovered the CMB in 1965
  9. 9. Tests of the Big Bang TheoryTests of the Big Bang Theory  Expansion of the universeExpansion of the universe  Cosmic microwave backgroundCosmic microwave background  Relative abundancesRelative abundances of hydrogen,of hydrogen, deuterium,deuterium, helium and lithium
  10. 10. Obtaining the Age of theObtaining the Age of the UniverseUniverse  Extrapolate the current expansion rateExtrapolate the current expansion rate (Hubble constant)(Hubble constant) back to the Big Bangback to the Big Bang • 10 to 20 billion years old10 to 20 billion years old  Look for the oldest starsLook for the oldest stars (in globular clusters)(in globular clusters) • 11 to 18 billion years old11 to 18 billion years old  Best current estimate isBest current estimate is 13.4 ± 1.6 billion years13.4 ± 1.6 billion years M10 Globular Cluster
  11. 11. Summary: Timeline of theSummary: Timeline of the UniverseUniverse
  12. 12. Timeline of the Universe 2Timeline of the Universe 2
  13. 13. The Big Bang TheoryThe Big Bang Theory  The violent expansion of anThe violent expansion of an extremely small, hot, and denseextremely small, hot, and dense body of matter between 12 and 18body of matter between 12 and 18 bya (billion years ago).bya (billion years ago).
  14. 14. Major EvidenceMajor Evidence 1.1. We are reasonably certain that theWe are reasonably certain that the universe had a beginning.universe had a beginning. 2.2. Galaxies seem to be moving apartGalaxies seem to be moving apart from each other.from each other. 3.3. We have found remnants of the heatWe have found remnants of the heat believed to be from the big bang.believed to be from the big bang. 4.4. The abundance of hydrogen andThe abundance of hydrogen and helium in the universe seems tohelium in the universe seems to support the theory.support the theory.
  15. 15. Big Bang TimelineBig Bang Timeline 1.1. The universe began with anThe universe began with an expansion of all the matter andexpansion of all the matter and energy of the universe.energy of the universe. 2.2. The universe begins to cool off.The universe begins to cool off. 3.3. Gravity begins to take effect andGravity begins to take effect and subatomic particles form.subatomic particles form. 4.4. The basic elements (hydrogen andThe basic elements (hydrogen and helium) form.helium) form.
  16. 16. Big Bang TimelineBig Bang Timeline 1.1. As the enormous cloud of hot gasAs the enormous cloud of hot gas cools electrons fuse with the basiccools electrons fuse with the basic elements to make heavier elements.elements to make heavier elements. 2.2. Stars begin to form and galaxies areStars begin to form and galaxies are formed.formed. 3.3. Stars are starting to die and puttingStars are starting to die and putting heavier elements into space.heavier elements into space. 4.4. Heavier elements combine to formHeavier elements combine to form planets that orbit a central star.planets that orbit a central star.
  17. 17. Fusion of StarsFusion of Stars  Smaller nucleiSmaller nuclei collide andcollide and fuse releasingfuse releasing a large amounta large amount of energy andof energy and creatingcreating heavierheavier elements.elements.
  18. 18. Elements up to the weight of iron are manufactured in stars. Elements heavier than iron are formed when a supernova explodes.
  19. 19. These gaseous supernova remnants glow in colors determined by the elements they contain. For example, the dark blue areas are rich in oxygen and the red material is rich in sulfur. Orion nebula, a region of intense star formation. Much of the brightness in this infrared view of the Horsehead nebula comes from PAH emissions. The Cat's Eye Nebula has an AGB star at its center.
  20. 20. Composition of the UniverseComposition of the Universe  Not StaticNot Static  Different areas of the Universe haveDifferent areas of the Universe have different compositions.different compositions.  Mostly Hydrogen and HeliumMostly Hydrogen and Helium
  21. 21. Composition of the EarthComposition of the Earth Element found in the Earth’s atmosphere Elements found on Solid Earth
  22. 22. Composition of the SunComposition of the Sun
  23. 23. Most Common ElementsMost Common Elements  UniverseUniverse 1.1. HydrogenHydrogen 2.2. HeliumHelium  EarthEarth • Solid EarthSolid Earth 1.1. OxygenOxygen 2.2. SiliconSilicon • Earth’s AtmosphereEarth’s Atmosphere 1.1. NitrogenNitrogen 2.2. OxygenOxygen

×