Download The Evolution of the Universe: from Cosmic Soup to Earth

The Evolution of the Universe: from Cosmic Soup to Earth October 26, 2011 Summary: The universe as we know it today originated from a massive explosion commonly referred to as the “Big Bang.” While this term is probably familiar to many of us, what does it really mean? Did all of the galaxies and solar systems as we know them today emerge preformed during this chaotic period, or did we actually just start with a simple mix of elements? To really under4stand what happened so many years ago, we turn to astronomers to help write the recipe for the cosmic soup that the “Big Bang” created. In this lecture, we journey from the earliest days of the universe when only a few of the elements we take for granted today existed, to how the first stars were formed, and how through the chaotic process of galactic recycling, the elements and solar system were created. Topics and Speakers: The Big Bang and Stellar Nucleosynthesis Ian Czekala: Ian Czekala is a second year graduate student in the Harvard Department of Astronomy. He works on observational studies of optical transients in the universe using the Pan‐STARRS survey telescope. A transient is any new source in the night sky that wasn't observed there previously. Once a new transient source is found, he uses a variety of x‐ray, optical, and radio telescopes to "follow up" on the source in exquisite detail. Once back at his computer, he then analyzes this data in order to discern the exciting new physical processes at work in these explosive transient objects. Setting the stage for Planets: Galactic Enrichment Nathan Sanders: Nathan Sanders is a Harvard graduate student in the Department of Astronomy. His research focuses on determining the physical processes in stars that lead to the brightest explosions in the universe. The evolution of the universe: Making planet Earth Elisabeth Newton: Elisabeth Newton is a second year graduate student in the Harvard Astronomy Department. She studies low‐mass stars, which have recently attracted the interest of the exoplanet community due to the relative ease of finding Earth‐sized planets orbiting them. Elisabeth graduated from the College of Creative Studies at UC Santa Barbara and enjoys traveling and hiking. Glossary •
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Big Bang: The initial point from which the universe began developing approximately 13.7 billion years ago. Cosmic Microwave Background: the leftover energy that can be detected from the initial Big Bang. Element: a pure chemical substance which is determined by the number of protons in its nucleus. For example, hydrogen is the lightest element with 1 proton while something more interesting and shiny like gold has 79 protons. The only way elements can be created is via nucleosynthesis and not via chemical reactions. Galactic Habitable Zone: the area within a galaxy that is favorable to the development of life based on the time that spot has been around and the amount of metals and relative “safety” (e.g lack of supernova) of that area. Metal: In astronomy, a 'metal' is any chemical element heavier than hydrogen and helium. Nucleosynthesis: the process of creating a new element, requires tremendously large amounts of energy only seen on earth in nuclear explosions. Nucleosynthesis ordinarily occurs within stars. Protoplanetary disk: the space surrounding a newly formed star from which the orbiting planets arise. Solar mass: The mass of the sun, about 2x10^30 kg or 330,000x the mass of the Earth. Stellar Explosion: the explosion of a star, can come in different levels of explosiveness from a nova to a supernova. Stellar Wind: our sun’s stellar wind can be seen in the form of the Aurora Borealis. It is simply charged gas that is ejected from a star. Supernovae: An enormously large (and as a result very cool) explosion of a star. Further Reading: Astrobites.com The three speakers are also authors for the astronomy website Astrobites.com, where they present the latest research in astrophysics in short, easily‐digestible 'bites.'