Cosmo%20Book%20Report

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School

University of Notre Dame *

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101

Subject

Geology

Date

Oct 30, 2023

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pdf

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Uploaded by ProfCoyote2962

Why Aren’t Black Holes Black? Authors: Robert Hazen and Maxine Singer Anchor Publishing 320 Pages Kathleen Kelly Abstract: Hazen and Singer explore the worlds of physics, earth sciences, chemistry, and biochemistry to examine the questions for which science has not answered and the current methods being used to pursue new knowledge. While discussing major breakthroughs and current knowledge, the authors also emphasize the many things scientists have not discovered and the limitations of modern technology. This book relates to the course through the discussion of certain cosmological concepts and with the shared idea that science is an ever-evolving field.

The main author, Robert M. Hazen is Senior Staff Scientist at the Carnegie Institution’s Geophysical Lab and Clarence Robinson Professor of Earth Sciences at George Mason University. He received his B.S. and S.M. in Geology at the Massachusetts Institute of Technology, his PhD in Earth Sciences at Harvard, and was NATO Postdoctoral fellow at Cambridge University. His recent research examines the roles of minerals in life’s origins. Hazen is a qualified professional with more than four decades of mineralogical research. The author writes about a large variety of scientific topics to demonstrate that scientific questions vary in scope and content and to demonstrate the limitations of modern science and technology. This book is interesting because, in his discussion of biology and chemistry, he reinforces how and why physics and cosmology impact other fields. Evidently, this book relates to Physics 10240 because chapters about the universe and cosmology are related to topics discussed in class. This book helped me work towards my goal of broadening my understanding of sciences–which is the same goal I had in mind when I enrolled in this course. Chapter 1 explores dark matter. Scientists know that dark matter exists because the visible mass of the galaxy–multiplying the number of visible stars by the average mass per star–is not the same as the dynamical mass of the galaxy–observing how stars move based on gravitational forces and measuring the position and orbital speed of stars and/or clouds of gas as they orbit the galactic center. Further, the outer parts of spiral galaxies moved 2-3 times faster than they should based on the gravity from visible sources. Scientists do not know for sure what dark matter is made out of. Some of the most likely explanations are massive compact halo objects (MACHOs), snowballs of hydrogen ice, black holes, hot dark matter, cold dark matter. However, MACHOs only represent about 20% of suspected dark matter in our galaxy. Additionally, hot dark matter and cold dark matter are hard to examine because they can’t have an electric charge, can’t interact with light or other forms of electromagnetic radiation, must be very small, and have significant mass. The next chapter examines the history of the universe–as seen through the light emitted from distant galaxies many billions of years before the Earth was born–in hopes of guessing its ultimate fate. We believe the universe to be expanding based on the redshifts of galaxies. Proof of the Big Bang theory and a static universe lies in the constant cosmic microwave background radiation, and the changing contents of the universe. We can determine the age of the universe by examining the spectra and chemical makeup of distant stars and by looking at radioactive isotopes and their decay rates. We do not know for sure how the universe will end, but there are three possible situations: an open universe that expands forever, the closed universe that falls back in on itself, and the flat universe in which the expansion rate slows to almost zero. The study of the universe as it was, is, and shall be is a question involving philosophy and belief. Chapters 1 and 2 are closely related to our class content, but expanded my cosmological knowledge about a variety of new topics. The third chapter describes the search for a “theory of everything”, a single set of equations that describes the properties and behavior of all kinds of matter and forces. We must understand the arrangement of matter’s fundamental particles and how nature's four

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