NASA’s Hubble Finds Universe Is Expanding Faster Than Expected

https://www.nasa.gov/feature/goddard/2016/nasa-s-hubble-finds-universe-is-expanding-faster-than-expected

In the article, “NASA’s Hubble Finds Universe Is Expanding Faster Than Expected”, relates to our 17th objective, “I can explain how astronomers know that the universe is expanding and how they determine the age of the universe”, accordingly. To begin, the article states that by using NASA’S Hubble Space Telescope, astronomers have discovered that the universe is expanding 5% to 9% faster than expected. This discovery was made by “refining the universe’s current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 percent” and had new improved techniques that helped these astronomers make precise distant measurements to other faraway galaxies. The process of this discovery began by these astronomers searching for galaxies that contained Cepheid and Type la supernovae stars. The Cepheid stars measured about 2,400 in 19 galaxies, which then led them to compare the observed brightness of both stars and were accurately measured. The calculated distances were roughly 300 Type la supernovae far-flung galaxies. After this, they compared these distances with the expansion of space as measured by the stretching of light from receding galaxies, which allowed them to calculate these two values by how fast the universe expands with time (Hubble constant). This Hubble constant value showed 45.5 miles per second per megaparsec, which proved the new value means the distance between cosmic objects will double in another 9.8 billion years. This aspect of knowing the current speeds and distances to further galaxies, including the rate of acceleration, allows astronomers to calculate how long it took for them to reach their current locations. Further on, the article also states that there are two possible explanations for the universe’s excessive speed. One being that dark energy may be shoving galaxies away from each other with greater strength and two being more energy from additional dark radiation could be throwing off the best ways to predict today’s expansion rate. This correlates with what we did in class with the dot activity. This activity had someone choosing a random dot calling it our “Milky Way”, then afterwards our professor would show an enlarged image of the dots over the top of the one chosen. This would show our class that these other dots were moving away from the central dot that was chosen in the beginning. We know that dark energy/matter is essentially the “backbone” of our universe, which is why many astronomers believe this is the reason why the universe is expanding. The expansion of our universe will seem to go on forever and eventually end up in darkness as a whole. In my opinion, I found this last objective to be one of the most interesting ones yet. I never thought about how the universe around us could be expanding and accelerating forever and to me that is crazy. This article, as well as the subject, really intrigued me to think about how the universe will be in the future and pointed out different aspects that caught my attention. Overall, I found this recent discovery and article to benefit me not only in terms of helping me write my blog post, but also have a better understanding of how astronomers determine the age of the universe and how it is expanding as well.

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