Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Origin and Formation of the Universe Thursday October 24 LT: I can list the evidence for the origin of the universe BR: What fascinates you most about space? 2 Monday 10/28 LT: I can cite evidence that the universe is expanding BR: describe why this statement is true or not? “To look out into space is to look back in time?” 3 Wednesday 10/30 LT: I can describe the life cycle of a star BR: What is a galaxy? What holds galaxies together? 4 Tuesday 10/29 LT: I can cite evidence that the universe is expanding BR: What had to happen in the early universe before matter could form? 5 Friday October 25 LT: I can tell how big, how far, and how old a star is based on objects surrounding it. BR: What support is there for the Big Bang? How big is space? 6 How big, how far, how old Put these in order of How big they are smallest to largest. We will discuss your choices afterwards. Try to come to an agreement. How big Sun Saturn Milky way Earth Moon Pleaides Hubble deep field 7 How Far Put these in order of nearest to Earth to farthest. We will discuss your choices afterwards. Try to come to an agreement Whirlpool Galaxy Pluto Moon Hubble Deep Field Sun Saturn Pleiades 8 How Old? Put these in order of How old they are youngest to oldest. We will discuss your choices afterwards. Try to come to an agreement Hubble deep Field Sun Stegosauras Moon Earth Pleiades Great Pyramid of Giza 9 How do scientists know about Earth’s formation? Scientists use direct observation and theoretical models to try to understand how the universe formed. 10 Origin of the Universe NOtes 11 Theories [models] of Universe Formation Big Bang Theory Steady State Theory 12 The Big Bang Theory The most widely accepted theory for the formation of the Universe 13 The Big Bang Theory All matter was once compacted in a tiny, dense particle, smaller than a piece of dust. The particle was compacted by extreme pressure and temperature 14 Building a Universe • an expansive event called the big bang instantaneously filled space with all matter and energy The Big Bang Theory The Big Bang Theory DOES NOT state that the universe was created from a “giant explosion”!!! 16 The Big Bang Theory 10-43sec Initial, hyper-(super fast) expansion, NOT an explosion! Matter and energy are propelled outward in all directions 10-32sec Hot soup of electrons, quarks and other particles 17 The Big Bang Theory 10-6sec 3minutes Rapid cooling allows quarks to clump into protons and neutrons protons and neutrons combine into atomic nuclei 300,000years electrons join nuclei to make atoms (mostly Hydrogen and Helium); light (photons) is emitted 18 The Big Bang Theory 1 billion years Gravity brings together atoms of H and He forming giant clouds that will become galaxies. 19 Galaxies, families of billions of stars 20 OUR galaxy, the Milky Way, a spiral galaxy 21 Big Bang Timeline 22 The Big Bang Theory Over the next 13.7 billion years, inflation continued and the universe cooled [-270C] Inflation continues today, and according to the BBT, inflation should never end… 23 Consequences of the Big Bang If the universe did come into existence through an expansive event, there should be some evidences: The mix of the elements should be known The universe should have a measurable Temp. The universe should be expanding Abundance of Light Elements Elemental composition of the present universe closely matches the predictions made by the BBT: Nucleosynthesis ABB Present day 76% Hydrogen 73% Hydrogen 24% Helium 26% Helium 25 Big Bang “After Glow” In the early moments following the BB, the universe was giving off large amounts of IR radiation (thermal energy) and visible light. As the universe expanded, it cooled. Weak radiation should be dispersed in all direction of space. 26 Arno Penzias and Robert Wilson Early 1960s - Penzias and Wilson are hired by Bell Labs to evaluate the performance of the new radio telescope to be used in trans-Atlantic telephone communications. They found a small, unexplained signal regardless of the direction the telescope is pointed. It is not enough to be a problem, but they are curious. 1964 - They become aware that the noise in their telescope is the cosmic background radiation predicted by the Big Bang theory. Bell Labs’ radio telescope. 27 COsmic Background Explorer In 1992, COBE announced a measurement that showed that the background radiation was ALMOST uniform This measurement confirmed the temperature to be app. 2.73K Remnant echo of the BB image of the (extremely tiny) anisotropies in the cosmic background radiation 29 Expanding Universe THE BALLOON ANALOGY SPACE between galaxies is increasing 30 Cluster of galaxies do not increase in size, but the galaxies move further apart 31 The expansion is similar to the baking of bread. The size of the bread increases and the distances between the raisins also increase, but not the raisins. If you sit on one of the raisins, you will see that all the raisins are receding from you. Besides, the farther away a raisin locates, the faster it recedes 32 In the 1920s, Edwin Hubble determines that the galaxies are: Edwin Hubble with his cat Nikolus Copernicus. (Colliers Magazine, 1949) Moving away from the Earth in all directions and The father away they are, the faster they move outward Hubble’s Law states that: as the distance increases, so does the velocity. This implies that the universe is UNIFORMELY expanding. 33 34 How was this known??? Hubble used a phenomenon first discovered by the Austrian mathematician and physicist, Christian Doppler (1803-53). The pitch of a note is how high or low it sounds. It depends on the frequency of the wave. Higher the frequency of a sound wave, shorter its wavelength, higher its pitch. 35 As the police car approaches, the SW from its siren are compressed towards the observer. The intervals between waves diminish, which translates into an increase in frequency or pitch. 36 Conversely as the police car recedes, the SW are stretched relative to the observer, causing the siren's pitch to decrease. 37 By the change in pitch of the siren, you can determine if the car is coming nearer or speeding away. 38 A change in pitch results from a change/shift in the frequency of the sound waves is referred to as the DOPPLER EFFECT. 39 Doppler Effect [Light] As the light from a galaxy travels away from us, the distance between us and that galaxy increases, thus light is “stretched” appearing redder. Red has a longer wavelength than Blue 40 41 Red Shift and Blue Shift The waves emitted by an object moving toward an observer are squeezed; its frequency appears to increase and is therefore said to be blueshifted. (shorter wavelength)] In contrast, the waves emitted by an object moving away are stretched or redshifted. (shorter frequency, longer wavelength) Blueshifts and redshifts exhibited by stars, galaxies and gas clouds also indicate their motions with respect to the observer. 42 The Universe is EXPANDING and SPEEDING UP 43 Galaxy’s velocity is proportional to its distance galaxies that are twice as far from us move twice as fast Every galaxy took the same amount of time to move from a common starting position to its current position 44 The Future of the Universe The rate of expansion of the universe is increasing. The universe will continue to expand forever, as suggested by the BBT, and stars making up the galaxies will age and die. as more stars die over billions of years, the universe will eventually grow cold and dark OR 45 The Future of the Universe The expansion will slow down as new matter is “formed” [E=mC^2], and will eventually stop It will begin to contract and collapse until the universe contracts back to a single point in a big crunch! PULSATING (OSCILLATING) THEORY 46