Week 8: Origins and the Universe

For me, the big question this week was, "How can we understand various concepts and processes of space and the universe's origin?"

1. What did you do in lab today? 

In lab this week, we heard presentations from each table group and Ted about the origin of the universe, the life cycles of stars, the origin of Earth, galaxies, black holes, and space exploration. My group presented on the origin of Earth. Below are the key things I learned from each group: 

Origin of the Earth (my group)

Origin of the Universe

• As we know it, the universe is 13.7 billion years old. 
• The Big Bang was the origin of the universe, not the origin of Earth. It is an expansion, not an explosion. 
• The Big Bang created atomic structure among millions of other things. Atoms started to combine with each other to form new elements with atomic numbers up to Iron. 

Life Cycles of Stars

• Stars start in a cloud of dust (nebula), then become either a Average or Massive star, then either a Red Giant or Red Supergiant (respectively), then either a planetary nebula or a supernova (respectively). At the end of their life, stars will either become a white dwarf or a black hole. 
• A star's mass at its birth determines how big it can get.
• The bigger a star, the faster is burns up, thus giving it less time to grow during its life cycle.

Galaxies

• There are trillions of galaxies
• Galaxies can have several different formation shapes

Black Holes

• Are formed when stars collapse under their own gravity
• They usually can't be seen

In lecture on Thursday, we unpacked the Misconceptions Die Hard reading. My biggest takeaway from this conversation was that we need to let kids learn and figure out concepts first before we give them big vocabulary words to describe them. 

Then, we went back over what we talked about in lab on Monday. This time was really helpful for me to make sure I got the information down. 

A few key things I learned were: 

• As stars/suns burn up, their mass decrease causes gravity to decrease, which causes them to inflate because there isn't anything to hold them to where they were at. 
• Earth's iron core causes a magnetic field around our planet to fight off the radiation from the Sun!
• There are 3 galaxy shapes: Spiral, Elliptical, and Irregular
• There is a huge black hole at the center of all galaxies, but only one photo has ever been taken of one by Katie Bouman. 

Pressbook Reading

What did you learn? 

• The textbook helped clear up why more mass automatically means more gravity. The more particles there are to pull in the same direction (because they're "clumped), the more pull there will be. 
• I also learned that the Moon has a core, mantle, and crust?! I don't know why I didn't know that before, but I didn't. This fact helps provide further evidence for the Theia theory that something Mars-sized collided with a molten-lava Earth, projecting some of Earth's material out into space and creating the Moon. 
• It was clarified for me that the Moon has enough gravity to pull water, and that's why it causes the tides. 

What was most helpful? 

A lot from this chapter was very helpful for my understanding, but what I think was most helpful were the explanations of the different theorized processes. This helped to solidify and expand on what I learned in class and in lab. 

What do you need more information on? 

I would like, but don't need, more information on the other scientific theories for the formation of the universe, solar system, and earth. I think it would be interesting to do a deep-dive on those alternative ideas too! 

What questions/thoughts/comments do you have? 

I am still unclear on exactly how scientists think black holes form. Where does all the material go when the star collapses, and where does everything go that is getting sucked in?