I read an article on astronomy.com entitled, “HOLiCOW! Astronomers measuring the expansion of the universe confirm that we still don’t understand everything.” The article, by Alison Klesman, states that in January of this year, the HOLiCOW collaboration’s H0 Lenses had released a most recent measurement of Hubble’s constant (H0). The Hubble constant tells us how fast the universe is expanding and helps estimate the size and age of our universe, as well how much dark matter is present in the cosmos, etc. The HOLiCOW team measures the expansion of the universe independently by “using quasars that have been gravitationally lensed by massive foreground galaxies in our line of sight.” Their results match other result measurements of the same value that have been measured from our universe; therefore, this is hinting that there may be some missing physics from the current cosmos model. The article goes on to discuss the HOLiCOW measurements, the Hubble constant (H0), and independently measuring H0.
Below is an image of a gravitational lens – part of HOLiCOW
This article correlates with our final conceptual objective, “I can explain how astronomers know that the universe is expanding and how they determine the age of the universe.” The article connects to what we learned in class because it discusses the Hubble constant, the unit of measurement used to describe the expansion of the universe, and how there may be more to learn about the expansion of the universe. Through a class discussion and from powerpoint slides, we learned that the Hubble constant tells us how old the universe is by taking the inverse of the H0 measured; that is how we know that the universe is roughly 14 billion years old. We also participated in an overhead demonstration in which Mr. Morrison placed one slide on the table and had a student pick one dot (representing galaxies) to represent the Milky Way. Then, he placed another slide with the same dot pattern, only larger this time, on top of the original slide. He made sure to put the “Milky Way” dot in the same spot. This demonstration showed that the “galaxies” appeared to be running away from us because the universe is expanding. Below is an image from the demonstration in class.
I really liked this article because I think it’s really amazing to know that we are learning more and more about the universe and its expansion every day. It is absolutely incredible to think about just how big the universe is; it is a lot to wrap ones head around. I found this article, and especially this final conceptual objective, to be intriguing. With this being our last conceptual objective, I wanted to share one of my favorite quotes… “The universe is full of magical things patiently waiting for our wits to grow sharper.” -Eden Phillpotts