BIG HISTORY I
Big History Short:
The Big Bang and how it unfolded:
The earliest universe was unimaginably dense and hot. But as the universe began to expand, it also began to cool down. During the first fraction of a second of our universe, the density and temperature until it decreased sufficiently into the different physical forces to separate into the ones we know today: electromagnetism, gravity and the weak and strong forces holding atoms together. As the universe continued to expand, it cooled further. As it cooled, more and more complex particles could stick together. Atomic particles, like protons, became stable within a couple of minutes. Dring the following eighteen minutes, the conditions were just right for fusion, the sticking together of atomic nuclei, and some of the protons and neutrons fused to form helium and a little bit of lithium. There would be no other elements around for hundreds of millions of years.
The Big Bang: Creatio Ex Nihilo?
Harvard Astronomer Dr. Karin Öberg explains:
Start: :34 Stop: 7:13
Process
Out of the Big Bang came everything in the Universe. All of the matter that formed Earth, all of the materials that formed the stars and galaxies that light up the night sky, all of the building blocks for everything in the Universe were once contained in a tiny singularity. Even space and time as we know them emerged from the Big Bang. That’s why the Big Bang is considered the first “new complexity” in the Universe and the first major threshold of increasing complexity in this course. Scientists, and all of us, are continuing to learn more about the Big Bang and how our Universe was formed.
You can join in this process of discovery by searching for new stories about the Big Bang and the history of our Universe. Use some of the suggested articles or find ones on your own that highlight new information that you think contributes to a discussion of the Big Bang today. Check out Newsela.com for great articles, or look at the Pinterest board Newsela set up on this topic.
Here are a couple of places to get started with your research:
Fr. George Lemaitre,
Father of the Big Bang Theory
This startling idea first appeared in scientific form in 1931, in a paper by Georges Lemaître, a Belgian cosmologist and Catholic priest. The theory, accepted by nearly all astronomers today, was a radical departure from scientific orthodoxy in the 1930s. Many astronomers at the time were still uncomfortable with the idea that the universe is expanding. That the entire observable universe of galaxies began with a bang seemed preposterous.
What exactly does the process of the big bang, the formation of stars, and the birth of planets mean to our lives?
What is Astronomy?
Astronomy is the branch of science that studies outer space focusing on celestial bodies such as stars, comets, planets, and galaxies.
History of Astronomy
Perhaps one of the oldest sciences, we have record of people studying astronomy as far back as Ancient Mesopotamia. Later civilizations such as the Greeks, Romans, and Mayans also studied astronomy. However, all of these early scientists had to observe space with just their eyes. There was only so much they could see. With the invention of the telescope in the early 1600s, scientists were able to see much further objects as well as get a better view of closer objects like the moon and the planets.
Major Discoveries and Scientists
Galileo Galilei made major improvements to the telescope allowing close observations of the planets. He made many discoveries including the 4 major satellites of Jupiter (the Galilean moons) and sunspots.
Johannes Kepler was a famous astronomer and mathematician who came up with the planetary laws of motion that described how the planets orbit the sun.
Isaac Newton explained the physics behind the solar system using his laws of celestial dynamics and gravitation.
In the 20th century we are still making major discoveries in astronomy. These discoveries include the existence of galaxies, black holes, neutron stars, quasars, and more.
Fields of Astronomy
There are different fields in the science of astronomy. They include:
Observational Astronomy - this is what we often think of with astronomy; observing the celestial objects of outer space such as stars and planets. There are actually types of observational astronomy that are divided up by how the objects are observed. These include everything from basic light (using our eyes to observe), radio, infrared, X-ray, Gamma Ray, and ultraviolet observations (using complex high-tech equipment).
Theoretical Astronomy - in this area of astronomy scientists use mathematical models to better describe what is observed and even to describe events we cannot observe with our current technology.
Solar Astronomy - these scientists focus on the sun. This can be an important field of science as sun activity can have a major impact on the Earth.
Planetary Astronomy - an area of science focused on learning more about planets, moons, asteroids, and comets. From this we can learn how planets and other objects were formed and what they are made of.
Stellar Astronomy - the study of stars including how they are formed, what they are made of, and their life cycle. This includes various types of stars and their final state including interesting objects like red giants, black holes, supernovas, and neutron stars.