The Invisible Universe: Why There's More to Reality than Meets the Eye Paperback – January 10, 2023

The Invisible Universe: Why There’s More to Reality than Meets the Eye by Mathew Bothwell“The Invisible Universe” is a fascinating “look” into the cosmic reality we can’t see. Astronomer and science communicator based at the Institute of Astronomy and the Kavli Institute for Cosmology at the University of Cambridge, Mathew Bothwell provides readers with an engaging and accessible guide to the invisible universe. This enlightening 308-page book includes the following nine chapters: 1. What is light?, 2. The hidden infrared cosmos, 3. Microwaves and the start of the Universe, 4. Monsters in the dark: the quest to find the Universe’s hidden galaxies, 5. Black holes: agents of destruction, agents of creation, 6. Astronomy at the longest wavelengths, 7. Dark matter: a cosmic ghost story, 8. Ripples in space and time and 9. Dark energy, and the future of our Universe.Positives:1. Engaging and well-written book. Bothwell does a wonderful job of guiding the reader through complex topics at an accessible level.2. The fascinating topic of the cosmic reality we can’t see.3. Bothwell’s expertise and background as an educator lends itself well for guiding the general public on what otherwise are complex topics. His writing style is engaging, accessible and with a touch of humor.4. Good use of diagrams and photos to compliment the excellent narrative.5. Describes light. “The best answer we can give – and this is still deeply mysterious and confusing – is that it is both at the same time. It’s a wave, and also a particle, all at once.”6. Understanding the three categories of infrared. “Using these ideas, we can broadly categorise the near-, mid- and far-infrared into rough temperature ranges. Near-infrared light will be emitted by things which are fairly hot – not quite as hot as our Sun, but still very hot by Earth standards, at hundreds or thousands of degrees Celsius. The mid-infrared will be emitted by things which are, more or less, around a comfortable room temperature. And the far-infrared, in turn, will trace the very coldest corners of the Universe.”7. Does a wonderful job of explaining key concepts concerning the life and death of stars. “This nuclear reaction, in which four atoms of hydrogen are crashed together to produce an atom of helium (and a bit of leftover energy), is what powers the Sun, and is responsible for all life on our planet.”8. Tells the story of modern cosmology. “Cosmology and astronomy are subtly different things: while astronomy is the study of the constituents of the Universe – like stars, planets and galaxies – cosmology concerns itself with the Universe as a whole.”9. Hubble’s most famous result discussed. “Hubble’s most famous result – and one of the most important astronomical results of all time – came when he compared the speeds of these galaxies with their newly measured distances. The results were clear and striking: firstly, all galaxies seemed to be moving away from us. Secondly, and most importantly, the further away a galaxy was, the faster it seemed to be travelling.”10. Throughout the book the author discusses astronomical discoveries that feeds on previous discoveries and help confirm scientific theories. “The existence of this ‘afterglow’ radiation – a fossil from the young, hot Universe – was a specific prediction of the Big Bang theory.”11. A wonderful analogy that resonated and that and that I use to explain the immensity of the universe. “Galaxy is to imagine shrinking everything down, until our Solar System is the size of a ten pence coin (with the Sun a tiny burning dot in the centre, and Neptune orbiting around the outer edge). Imagine this coin-sized Solar System lying on the floor in front of you. How big would our Milky Way be in this model? A few hundred metres? Several kilometres, even? In actual fact, on this scale the Milky Way would be roughly the size of Europe.”12. Describes the main purpose of the James Webb Space Telescope (JWST). “Webb’s primary science goal, however, is to look back further than ever before and finally glimpse the primeval stars and galaxies that produced the first light in the Universe.”13. A “look” at black holes. “The answer is that we can’t see the black hole itself, but we can certainly see the effect the black hole has on the things around it. And black holes, having the most powerful gravitational fields in the Universe, have an effect on their surroundings that is hard to miss.”14. The key substance of the universe. “Hydrogen is both the simplest and most abundant substance in the Universe. It is, in fact, the simplest substance that can possibly exist: one proton, with one electron orbiting it, and nothing more. This simple stuff makes up around seventy-five per cent of all the normal matter in the Universe (I’m using ‘normal matter’ here to mean ‘baryons’, the physics term for normal material made up of protons and neutrons – we’re not counting stuff like dark matter here, which far outweighs everything else put together).”15. The evidence for dark matter discussed. “A lot of the evidence for the mysterious stuff astronomers came to call ‘dark matter’ is based on the behaviour of gravity.”16. The predictive power of science. “Given that they had a good understanding of how gravity should work, their best guess was that there had to be something out there they could not see, tugging on Uranus and causing it to do unexpected things. And they were completely right: Neptune turned up, exactly as predicted.”17. The search for gravitational waves. “The third grand revolution in astronomy happened at 4:50 a.m. on 14 September 2015. In January the following year (such a significant discovery needed to be checked and rechecked, of course, which took a few months), my Cambridge colleagues and I sat in a packed lecture theatre to hear the historic live-streamed announcement: a team of astronomers had detected gravitational waves, a completely new way to see the Universe.”18. The grand theory of General Relativity by Einstein. “Using General Relativity, we can now give Newton an answer. Gravity is not a mysterious pulling force which acts at a distance; it’s just what happens when you move through curved space.”19. The enlightening topic of dark energy. “Dark energy, on the other hand, is far more mysterious. It could well be some sort of springy ‘pushing force’ built into the very fabric of the Universe itself (I’ll get to some ideas for how that might work below). They even act in opposite ways: dark matter attracts, while dark energy repels.”20. Includes a Suggestions for further reading section.Negatives:1. I would have added a timeline of major cosmological events.2. Some extras like a glossary of key terms would have been beneficial.In summary, an excellent book on astronomy/cosmology that focuses on the invisible spectrum of the universe. Mathew Bothwell is indeed a gifted writer; he takes complex concepts of science and makes it accessible to the layperson. The book keeps your interest without bogging you down with formulas. Bothwell is an excellent communicator and I look forward to more books in the future. So much to like here, I highly recommend it!Further recommendations: “Universe in Creation: A New Understanding of the Big Bang and the Emergence of Life” by Roy R. Gould, “A Universe from Nothing” by Lawrence Krauss, “Until the End of Time”, “The Elegant Universe” and “The Hidden Reality” by Brian Greene, “The Big Picture: On the Origins of Life, Meaning, and the Universe Itself and “From Eternity to Here: The Quest for the Ultimate Theory of Time” by Sean M. Carroll, “Origins: Fourteen Billion Years of Cosmic Evolution” by Neil deGrasse Tyson, , “To Explain the World: The Discovery of Modern Science” by Steven Weinberg, “Why Does E=mc2?” and “Wonders of the Universe” by Brian Cox, “Longitude” by Dava Sobel, “Cosmos” by Carl Sagan, and “The Grand Design” by Stephen Hawking.

Matthew Bothwell explains many aspects of astronomy in a ways that is simple to understand and very informative. It held my interest like a well written novel!

As a person with scientific training but limited experience with cosmology, this book was a perfect fit.I felt the information was presented perfectly; with enough detail to be instructive but not a mathematics lecture.Would recommend for anyone interested in the subject and with some basic physics understanding.

Astronomy and cosmology and the physics related have been a passion most of my life, but often I have found several aspects difficult to understand. The author is by far the most easily understood science communicator I have ever encountered. Truly gifted. I came away from this book with a much better understanding of our universe and the work being done to attempt to understand what astronomers are finding. Highly recommend this book to anyone curious to learn about the universe and the mysteries within but lacking a physics/higher math background.

Every one who can read need to read this .... everybody else is a looser.In simple terms author takes reader on a trip down universe (like taking you down town of the down town you remember). The author does not use 'notes attached' and remind you of a previous point made which make reading for me easy.What is the space and time of simply LIGHT and the impact had on humanity. My ignorance could not fathom this.I have no doubt this will be your most important book in your life.

The topics hit the key issues in cosmology and the author does a magnificent job explaining them to the layman. I almost think I understand!

One of the greatest mysteries of science is where our universe came from, and where it is going. We've been making progress on this mystery for 500 years, peeling back one layer of the onion at a time (and often crying when we get things wrong, perhaps). Matt Bothwell gives a beautifully written, fact-filled, deeply engaging account of that history, taking us right up to current theories of dark matter and dark energy (a fundamental fifth force of nature?). This book will fill you with wonder and awe with respect to the cosmos. If our cosmos is a replicator in the multiverse, as Lee Smolin and others have proposed, it will also make you curious about how much intelligence our universe contains in its "genes" and emergent structure, and our own relationship to its future, and how many other intelligences might exist within it, and whether we will ever meet those intelligences, and if so, what benefit that might confer on the universe. Science is the most satisfying and edifying adventure the human mind can take. This book gives a glimpse at one of the central mysteries in that adventure.Books on the origin of life, the nature of consciousness, the miracle of biological development, accelerating universal change (since large scale structure formed), the relationship between information and physics, the nature of black holes, the (slow) arc of progress and moral advancement in human networks, and the ways those networks learn from catastrophe and error (eg, species extinction and climate change) are other mysteries well worth contemplating. Science is giving us insights into all of them today. Such an exciting time to be alive.

A great book if you are serious about astronomy. Interesting new information on galaxies.

Multiwavelength astronomy is properly explained. Matthew Bothwell is a good communicator, he reminds me of John Gribbin in his ability to explain a subject. My only gripe is Bothwell just like Gribbin before him, is not keen to use diagrams. A diagram can save a hundred words . This book is brim-full of super facts. Most book and magazine articles churn over the same facts ad nauseam.I have already bought another copy of The Invisible Universe for my brothers Christmas

If you only ever read one book on cosmology / astronomy then this is the one I would strongly recommend. Beautifully written on a subject the author clearly loves, this is a fantastic book which I didn’t want to end.

A fascinating and wonderfully informative account of the history and current state of cosmology. Beautifully and clearly written, and very readable.

Wonderfully lucid and up to date explanations, especially of infrared astronomy.