330 likes | 445 Views
THE BIG BANG Shelley Kauffman Albright College skauffman@alb.edu. http://www.youtube.com/watch?v=TzhIfN4UQv8. It all started with a Big Bang! (Maybe more of a buzz than a bang). http://faculty.washington.edu/jcramer/BBSound.html. http://scaleofuniverse.com /. ~ 4.6 billion-year-old earth.
E N D
THE BIG BANG Shelley Kauffman Albright College skauffman@alb.edu http://www.youtube.com/watch?v=TzhIfN4UQv8
It all started with a Big Bang! (Maybe more of a buzz than a bang) http://faculty.washington.edu/jcramer/BBSound.html
~ 4.6 billion-year-old earth ~ 13.7 billion-year-old universe
In your own words, describe the Big Bang http://b.socrative.com/ Or download the app on your ipad ROOM: 799311 “All of the matter in the universe was condensed into a particle smaller than an atom called a singularity, the singularity then exploded, rapidly sending matter out into empty space, creating the universe.” –Adam, 12 http://www.youtube.com/watch?v=wNDGgL73ihY
According to the Big Bang model, the universe, originally in an extremely hot and dense state that expanded rapidly, has since cooled by expanding to the present diluted state, and continues to expand today. But how do we know this?
The Big Bang Model is supported by a number of important observations: The expansion of the universe Edwin Hubble's1929 observation that galaxies were generally receding from us provided the first clue that the Big Bang theory might be right. The cosmic microwave background (CMB) radiation The early universe should have been very hot. The cosmic microwave background radiation is the remnant heat leftover from the Big Bang. • The abundance of the light elements H, He • The Big Bang theory predicts that these light elements should have been fused from protons and neutrons in the first few minutes after the Big Bang. These three measurable signatures strongly support the notion that the universe evolved from a dense, nearly featureless hot gas, just as the Big Bang model predicts. http://map.gsfc.nasa.gov/universe/bb_tests.html
http://www.sciencechannel.com/tv-shows/wonders-with-brian-cox/videos/wonders-of-the-universe-the-big-bang.htmhttp://www.sciencechannel.com/tv-shows/wonders-with-brian-cox/videos/wonders-of-the-universe-the-big-bang.htm
QUARKS? This is starting to feel a bit more like science fiction, so let’s have a look at the current state of the SCIENCE
THE EXPANDING UNIVERSE In 1929, astronomer Edwin Hubble made a truly startling discovery. By examining the light emitted from neighboring galaxies and making detailed observations of an electromagnetic property called REDSHIFT, Hubble showed that other galaxies appeared to be accelerating away from the Milky Way. The Universe is actuallyexpanding...
LET’s SEE FOR OURSELVES HOW REDSHIFT WORKS:Cut the rubber band so it's no longer a loop. Stretch the elastic and secure its ends to sturdy supports (chair rungs/pencils will work). One one side, mark the elastic into 1 cm lengths. These marks will represent wave crests. Mark a star in the center of the band. Notice how the wavelength marks are the same distance apart on both sides of the star. Grasp the star or center mark and stretch it in the direction of one of the supports. http://www.pbs.org/safarchive/4_class/45_pguides/pguide_501/4551_universe.html
QUESTIONS What happens to the 1 cm markings? What happens to the waveforms? Considering that this model represents red shift, on which side of the star would the observer on Earth most likely be? What happens to the temperature as the wavelength increases?
What Na looks like in the lab What Na looks like in a star moving away from you What Na looks like in a star moving away from you at an even faster rate
What happens to the wavelength as we shift toward the red end of the spectrum?
The Big Bang model was a natural outcome of Einstein's General Relativity as applied to a homogeneous universe. However, in 1917, the idea that the universe was expanding was thought to be absurd. In 1929, Edwin Hubble announced that his observations of galaxies outside our own Milky Way showed that they were systematically moving away from us with a speed that was proportional to their distance from us. The more distant the galaxy, the faster it was receding from us.
: 1. Inflate the balloon until it is approximately 10 cm across. Twist and fold over the mouth of the balloon. Have your partner secure it to keep it from deflating. Using the permanent marker, make 9 dots randomly across the balloon’s surface. Avoid making any marks near the part of the balloon where you blow it up. Label each dot with the letters A thru F. 2. Using the string/ruler, measure the distance between point A and every other point (B thru F). Record this information in the row labeled ‘1st measurement’. See the table below for a model.
3. Carefully inflate the balloon until it has a diameter twice as large as the first. Secure the balloon to prevent it from deflating. Once again, use the string to measure the distance between point A and every other point. Record this information in your table under ‘10 yr. Measurement’. 4. Using the data from your table, calculate the difference between the 1st and 10 yr. measurements for all points, and enter the answer under ‘Distance increase’. What would happen to the wavelength of light released from your dots as space expands? *An extension, given more time, PREDICT where the dots will be after 20 years of inflation
km/s (megaparsecs) Hubble constant ~68km/sec/megaparsec ~42miles/sec/megaparsec 1 megaparsec = 3.3 million light years
COSMIC MICROWAVE BACKGROUND During the first 380,000 years after the Big Bang, the universe was so hot that all matter existed as plasma. During this time, photons could not travel undisturbed through the plasma because they interacted constantly with the charged electrons and baryons, in a phenomenon known as Thompson Scattering. As a result, the universe was opaque. After this dark period, light emerges…
Arno Penzias and Robert Wilson with the Horn Antenna used to discover the Cosmic Microwave Background. (One of their first theories was that pigeon droppings may have been the culprit, but a simple cleaning disproved that theory) Arno Penzias and Robert Wilson with the Horn Antenna used to discover the Cosmic Microwave Background. Accidental Discovery In 1964, Bell Laboratory scientists Arno Penzias and Robert Wilson were trying to detect sources of radiation that might potentially harm satellites. Their data, however, showed background noise from a microwave signal corresponding to a temperature of approximately 2.7 K that appeared to be emitted from every direction. This apparent aberration was recognized by scientists at Princeton as remnant radiation from the earliest observable moment in the evolution of the universe, now called the Cosmic Microwave Background.
Light from the CMB is redshifted as the universe expands, cooling it over time. The CMB is a perfect example of redshift. Originally, CMB photons had much shorter wavelengths with high associated energy, corresponding to a temperature of about 3,000 K (nearly 5,000° F). As the universe expanded, the light was stretched into longer and less energetic wavelengths. Light from the CMB is redshifted as the universe expands, cooling it over time. The CMB is a perfect example of redshift. Originally, CMB photons had much shorter wavelengths with high associated energy, corresponding to a temperature of about 3,000 K (nearly 5,000° F). As the universe expanded, the light was stretched into longer and less energetic wavelengths.
Credit: NASA / WMAP Science Team WMAP # 121238 Image Caption 9 year WMAP image of background cosmic radiation (2012) 9-Year Microwave Sky: The detailed, all-sky picture of the infant universe created from nine years of WMAP data. The image reveals 13.77 billion year old temperature fluctuations (shown as color differences) that correspond to the seeds that grew to become the galaxies. This image shows a temperature range of ± 200 microKelvin. (When the CMB was initially emitted it was not in the form of microwaves at all, but mostly visible and ultraviolet light. Over the past few billion years, the expansion of the universe has redshifted this radiation toward longer and longer wavelengths, until today it appears in the microwave band.)
Abundance of H and He are what was predicted based on the Big Bang model https://www.ted.com/talks/david_christian_big_history#t-312816
Abundance of hydrogen and helium Stellar processes are unable to produce the abundances of H and He observed H and He are observed at levels that are predicted by the Big Bang Theory
Elements heavier than lithium are all synthesized in stars. During the late stages of stellar evolution, massive stars burn helium to carbon, oxygen, silicon, sulfur, and iron. Elements heavier than iron are produced in two ways: in the outer envelopes of super-giant stars and in the explosion of a supernovae. All carbon-based life on Earth is literally composed of stardust.