{"id":152,"date":"2019-06-15T00:14:57","date_gmt":"2019-06-15T00:14:57","guid":{"rendered":"https:\/\/pressbooks.usnh.edu\/methods\/chapter\/origins\/"},"modified":"2023-03-24T15:03:19","modified_gmt":"2023-03-24T15:03:19","slug":"origins","status":"publish","type":"chapter","link":"https:\/\/pressbooks.usnh.edu\/methods\/chapter\/origins\/","title":{"raw":"Origins and the Universe","rendered":"Origins and the Universe"},"content":{"raw":"Formative Assessment: Timeline of the Universe<\/a><\/strong>\n\n[caption id=\"attachment_151\" align=\"aligncenter\" width=\"1487\"]\"\" This timeline shows the key events in the formation of the universe. Each event is explained in more detail in this chapter.[\/caption]\n\nThe Big Bang: Origins of our Universe<\/strong>\n\nThe Big Bang is the best-supported scientific theory for how the universe was created. 13.7 billion years ago there was nothing and nowhere. Everything that ever existed was contained in a subatomic particle that was billions of times smaller than an atom. Within a fraction of a second, this amazingly tiny particle stretched and inflated to an unimaginably huge size. Space, time, and the fundamental particles of the universe were created in this instant.\n
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Key Takeaway<\/p>\n\n<\/header>\n

\n\nAlthough the word \"bang\" is part of the name, the [pb_glossary id=\"319\"]Big Bang[\/pb_glossary] was an expansion<\/strong> or an inflation rather than an explosion.\n\n<\/div>\n<\/div>\nAlthough there are alternate theories, the Big Bang theory is supported by multiple sources of scientific evidence.\n
    \n \t
  1. Edwin Hubble discovered that the universe is still expanding today. If it is constantly expanding and growing now, that means it was smaller before--and likely the size of an unimaginably small particle at the beginning.<\/li>\n \t
  2. Scientists detected Cosmic Microwave Background, a type of radiation that is present everywhere in the universe. Evidence suggests that this is leftover radiation from the energy of the Big Bang.<\/li>\n<\/ol>\nFor more explanation of the Big Bang theory, watch the following video.\n\nhttps:\/\/www.youtube.com\/watch?v=eUF59jCFcyQ\n
    Video credit: \"Big Bang Introduction<\/a>\" by Khan Academy<\/a> is licensed under CC BY-NC-SA 3.0<\/a>. Note: All Khan Academy content is available for free at khanacademy.org<\/a>.<\/h5>\nThe Life Cycle of Stars<\/strong>\n\nAll stars begin their lives as clouds of gas and dust which are called [pb_glossary id=\"261\"]nebulae[\/pb_glossary]. The particles in a nebula start to attract, so their combined mass increases. Therefore, they have more gravity which pulls in even more particles. Eventually, there will be enough particles under intense heat and pressure in the center core and [pb_glossary id=\"260\"]nuclear fusion[\/pb_glossary] can occur. The star ignites and becomes a fully functioning star.\n\nThe image, below, shows the life cycles of different types of stars.\n\n[caption id=\"attachment_151\" align=\"aligncenter\" width=\"1024\"]\"\" Life Cycle of Stars \"Universal Element Formation<\/a>\" by Science Learning Hub-Pokap\u016b Akoranga P\u016btaiao, University of Waikato<\/a>[\/caption]\n\nDepending on the amount of material in the nebula, an average star (like the Sun) or a supermassive star is formed. As the star burns through its fuel, it loses mass; therefore, it has less gravity and its size increases.\u00a0An average star turns into a [pb_glossary id=\"263\"]red giant[\/pb_glossary]. As it continues burning fuel, the red giant becomes very large. Then, the outer layers are blown off creating a planetary nebula and the inner core of the star remains, called a white dwarf star.\u00a0<\/span>\n\nA supermassive star turns into a super red giant. These stars have more mass so they burn through their fuel more quickly, therefore losing gravity and becoming extremely large. Eventually, the super red giant will run out of fuel, collapse in on itself, and create a giant explosion called a [pb_glossary id=\"262\"]supernova[\/pb_glossary]. From there, the star can either form a [pb_glossary id=\"254\"]black hole[\/pb_glossary] or an extremely compact neutron star.\n
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    Interesting Fact: We Are Made of Stardust<\/p>\n\n<\/header>\n

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