Monday, July 6, 2020

Einsteins Greatest Blunder - Free Essay Example

American astronomer, Donald Goldsmith, was born on February 24, 1943. He studied astronomy at the University of California at Berkeley and earned his PH. D. in 1969. Over the course of his life, Goldsmith has written over twenty books related to science and astronomy, one of his more popular ones being Einsteins Greatest Blunder. Donald Goldsmith is a respected astronomer and author, and has received the American Institute of Physics Science Communication Award and the Annenberg Lifetime Award for astronomy popularization from the American Astronomical Society. In this book, Donald Goldsmith strives to point out the biggest questions in cosmology today, and discusses why astronomers are having difficulties solving these inquiries. He also introduces possible solutions to these problems based on new information from the latest astronomical satellites. Goldsmith takes the first half of the book to explain how astronomy has developed over the past 500 plus years in a way that anyone, including non-scientists, can understand. He then dives into the current problems in this field of study faced by astronomers today. This is a very effective and interesting way of setting up this book as it allows the reader to utilize the information learned in the beginning of the book to make inferences about possible solutions to current issues in cosmology. The topics covered in this book range from topics as small as the discovery of new particles, to as large as the discovery of black holes and dark matter. It is very interesting to see how every new disco very builds off one another, and how many different branches of science are required to come together to figure out the greatest puzzle of all the universe. This book directly relates to the Physics 10240 course because it discusses a timeline of the biggest cosmological discoveries in past years, while also describing the methods and principles that cosmologists had to utilize in order to form these theories about the universe. Ideas, including the Doppler Effect, the curvature of space, and Einsteins theory of general relativity, that we learned about in class from Kip Thornes book, Black Holes and Time Warps, were also explained in this book, but at a more basic level. The book, Einsteins Greatest Blunder, is subtly, yet strategically, split up into two parts. The first eight chapters discuss information about cosmology and the universe that is known as facts, or is at least widely accepted as fact. It includes information about the wavelengths and frequencies of light, the process by which stars shine, how to detect the ages of stars, the location of galaxies in the universe, and more. He uses proven equations and laws, such as Newtons Laws of Motion and Einsteins famous energy of mass formula, to support the reliability of the information he is providing. The first two chapters of this book introduce some of the main questions asked by cosmologists today, like will the universe always continue to expand, or will it eventually contract, and what type of matter makes up most of the universe? Then, Goldsmith begins describing fundamental knowledge about gravity, light, and motion that is required to later understand more complex theories about the m ysteries of the universe. He refers to Newtons universal law of gravitation, Newtons laws of motion, and Newton and Einsteins astrophysics work, along with studies of spectroscopy (the study of different colors of light) to explain the facts of these topics. Right in the beginning, Goldsmith also defines what Einsteins greatest blunder was the cosmological constant. This term that Einstein introduced was used in his mathematical models so a universe without expansion or contraction could exist (7). Once Hubble later discovered that the universe is currently expanding, Einstein regarded this constant as his greatest blunder, however, some scientists still use a non-zero cosmological constant in Einsteins original equations in order to keep their theories in agreement with observations (8). Chapters three and four begin to get into characteristics of stars and the formation of galaxies. Goldsmith explains that nuclear-fusion (the melding of two atomic nuclei to form a new nucleus) at a stars extremely hot center is the process that allows for stars to shine. He also described that differences in the mass of a star dictate the stars characteristics after it stops burning. The lightest stars eventually become white-dwarfs, while heavier stars may become a neutron star or a black hole. These differing types of stars have been observed in the universe as telescopes have become more advanced over the years. Galaxies, or clusters of stars, were first discovered by Galileos telescope, but the differing types of galaxies were discovered centuries later. The general idea in this part of the book is that more concentrated groups of stars are called global clusters, whereas open clusters represent much smaller groups of stars. In addition, nebulae, and more specifically spiral neb ulae, describe the shapes of galaxies like the Milky Way, and were discovered through telescopes by astronomers like Charles Messier and Edwin Hubble. These varying arrangements of galaxies in the universe is something currently being investigated by astronomers today, which leads to the next topic discussed in the book Universal Expansion. The next several chapters contain information known about the current expansion of the universe, and current questions about the ultimate fate of the universe. Starting from the beginning, the Big Bang is the moment when the universe came into existence. It began with many particles, including protons, neutrons, electrons, and photons, which eventually became the ever-growing universe we know (for the most part) today. In order to answer the major question of whether the universe will always continue expanding, or if it will eventually begin to contract on itself, scientists would need to find the average actual density of matter in the universe to compare to the critical density, and would need a better understanding of Hubbles Constant (the unit of measurement used to describe the universes expansion). This leads cosmologists to the second big question of what matter actually makes up the universe. Goldsmith mentions the huge mystery of dark matter, and the issue of actually being able to discover and study it due to its lack of electromagnetic radiation and visible light. Finally, he wraps up the book by predicting that as scientists develop better telescopes and infrared detectors, as long as gain knowledge about Hubbles Constant and the kinds of dark matter still undiscovered, we may have a much better understanding of how galaxies formed, and what the fate of the universe is. In conclusion, this book was a good read because it was very informative and easy to understand. It included pictures taken with the Hubble Space Telescope, and many diagrams the help explain the main concepts described. These visuals, along with the simplified, straightforward diction made the book a good read for even those who have no prior knowledge in the subject of cosmology. For that reason, I would say this book is not targeted necessarily toward a specific age group, but more towards anyone with an interest in cosmology and little to no prior understanding of the universe and all of its contents. The last four chapters of the book were the best, in my opinion, because they discussed the questions cosmologists have today, and the progress, if any, that is being made in these areas. More specifically, chapters eleven and twelve talk about missing matter, and how most of the universe is made up of dark matter, which cannot be seen by way of visible light nor through electromagn etic radiation. The only way astronomers actually know that dark matter not only exists, but in fact makes up at least 5 to 10, maybe even 50 times more matter than matter that is familiar to scientists, is through how it affects gravity. Dark matter is still one of the biggest cosmological issues in discussion today, and at the time this book was published, governments in the United States and Europe had a number of dark matter searches being funded in places like California, Russia, and Italy. My least favorite chapter was probably chapter eight, The Exclusive Age of the Cosmos, because estimates of the age of the universe are based on a number of fudge factors as Goldsmith likes to call them, which are theories not proven to be true, but that models are based off of and are only valid if these factors are correct. One of the main questionable factors mentioned in this chapter is Hubbles Constant. It has been found that 1/H (H being Hubbles Constant) is the amount of time that has passed since the Big Bang, but scientists have yet to figure out what this age is. Estimates of the age of the universe range from roughly 6 billion years all the way to 13 billion years, which is such a large range that the actual age of the universe is, in my opinion, still a huge unanswered question. Overall, I would recommend that Einsteins Greatest Blunder stays on the reading list as it is very informational, and gives a simplistic, clear explanation of many of the cosmological concepts rel ating to content discussed in this course. In addition, it introduces many of the biggest questions about the universe that are still unanswered today.

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