Our last post is for extra credit and therefore not mandatory. Up to 10 points will be awarded depending on the thoroughness of your response. These 10 points will be added to your final course grade.
Construct a timeline for the universe and indicate when various significant events occurred, from the beginning of the expansion to the formation of the Sun to the appearance of humans on Earth. Make it a simple list, starting with what many physicists refer to as the “moment of creation” as 0 in your calendar. Make sure to add approximate dates and a brief description to each event. For example:
150 million – 1 billion years: Earliest structures and stars emerge.
Be thorough but remember to focus on significant events only.
Then post a thoughtful reply to at least one other post by any of your classmates comparing and/or contrasting your timeline to theirs.
*** This discussion will close on the last day of the semester, which is March 9. No late submissions will be accepted regardless of circumstance.
EXAMPLE
With the assumption that the universe is about 14 billion years old, the timeline for the universe and the events that occurred may look something like this:
The beginning- Big Bang theory, time and space are created.
In a fraction of a second- rapid expansion occurs within 3 billionths of a second, and the universe is the size of a grapefruit.
High energy particle reactions- at 1second
The first nuclei form- at 100-1000 seconds, nuclei of hydrogen, helium, lithium, and other light elements form.
The first atoms form- at 300,000 years, radiation can be detected from the early formation of the universe.
First galaxies and stars form- at a few hundred million years, protogalaxies form and the first stars form within them.
Expansion of the universe accelerates- at a few billion years, at first the universe decelerated, but at this point after the Big Bang, the expansion began to accelerate because of a force known as dark energy.
Formation of the solar system, including Earth- at 9 billion years, the sun, planets, asteroids, and comets form from the debris left by older generations of stars.
Life on Earth starts- at 10 billion years, the first life starts on Earth. In the form of cells and spreads across the globe.
Today- at 13.7 billion years, the universe now contains billions of galaxies, each with billions of stars, and within our own galaxy, hundreds of exoplanets have been discovered orbiting other stars.
