Knocking on Heaven's Door: How Physics and Scientific Thinking Illuminate the Universe and the Modern World Reprint Edition

I am a lawyer, not a scientist. I found this book understandable for someone like me. Fortunately, the author added an introductory section about the discovery of the Higgs-Boson because it had not yet been discovered when the book was published. Randall is a highly competent writer. This is not a simple book. One have to re-read a few paragraphs to understand them. The primary subjects are physics, particularly particle physics, and astronomy. I read a lot of popularized science material; my brother, who is as intelligent as I but doesn't read much science, found the book very tough going and quit it. Randall is awed by the beauty of science and by the work done by other scientists and convey her enthusiasm very well.

I just finished Randall's book Warped Passages and enjoyed it very much. So it was with anticipation that approached reading this book. Randall notes the intended audience for this book saying that it "is intended for an interested lay reader who would like to have a greater understanding of current theoretical and experimental physics and who wants a better appreciation of the nature of modern science - as well as the principles of sound scientific thought." The title is explained in the book: "Scientists knock on heaven's door in an attempt to cross the threshold separating the known from the unknown."

She begins by discussing the many misconceptions people have about science today and introduces us to the concept of effective theories, which is a technique scientists use to study "particles and forces that have effects at the distances in question." A whole chapter is then spent on the contribution of Galileo in establishing the foundations of science thought. Some time is spent discussing the different aims for science and religion. She notes that the goals of science and religion are intrinsically different. Science addresses physical reality, whereas religion tends to be concerned with psychological or social human desires. Early modern scientists actually viewed the "Book of Nature" and the "Book of God" as similar paths to edification and revelation.We are next taken on a journey from the sub-atomic scales all the way down to something known as the Planck length (10-33 cm). We learn of the discoveries of electrons and quarks, fixed-target verses particles colliders, the Higgs mechanism, and more.

Section III of the book delves into the machinery and measurements behind the science, notably the Large Hadron Collider (LHC) at CERN. A chapter is spent discussing the conception, construction, first tests, and problems encountered with the LHC. Some feared the LHC would be capable of producing black holes, and maybe even destroy the earth. Randall puts our fears at bay by explaining all we need to know about this. She continues by discussing calculating and dealing with risk citing common examples such as climate change and the financial crisis and explains how risk can be mitigated. The next topic deals with measurement and uncertainty where we learn the meaning of the terms accuracy, precision, and systemic uncertainty. A chapter is devoted to the CMS and ATLAS experiments. These are the two general purpose detectors of the LHC. They are incredibly large and extremely complex wonders of engineering. Perhaps Randall's own theories will be verified here. Space is devoted to explaining in more detail the detection system. Here we have the trackers (innermost part of the detector), the electromagnetic calorimeter, the hadron calorimeter, and on the outermost part of the detectors we have the muon detector. There are many images provided to show us all that is described in the text.

Section IV of the book deals with the topics of modeling and prediction of results. The concept of beauty and its relationship to science is explored, and we are given some insight into the process of model building. This segues into the nature of the Higgs boson, the Higgs field, symmetry breaking, and how the Higgs imparts mass to particles via something called the Higgs mechanism. We also learn about how the particles produced in the LHC can be used to identify the "fingerprints" of the latest theories. One theory of the author, called the Randall-Sundrum theory, proposes a warped geometry involving two types of branes in close proximity. Randall expresses the anxiety provoking nature of waiting for the LHC results. She notes that "They could change our view of the underlying nature of reality [...] When the results are in, whole new worlds could emerge. Within our lifetimes, we just might see the universe very differently." The text would not be complete with a discussion of inflation, dark matter and dark energy. We are informed of the various dark matter detection methods, and the various experiments worldwide that are being conducted in a attempt to detect it.

Randal has given us here a glimpse into the world of high-energy physicists and cosmologists, their hopes, and the experiments that could answer the fundamental questions about the universe we live in.

Light on physics, heavy on Randall's opinions and life experiences. A lot of these physics books have a ton of history of physics for the fist 5 chapters or so (like "from Archimedes to Einstein", so to speak) but then they dive into the modern physics that the reader was looking for. In Randall's book, instead of history of physics, the first chapters are all about the history of her professional life, lectures, books, political conversations, etc.. Disappointing.

This is a great book to read for those who want to understand what current research tells us about quantum physics and cosmology. Randall explains contemporary ideas in a manner that those who do not have a background in science or math can easily comprehend. She also gives the reader a good idea of how actual scientific theories and experiments are developed and tested. I thoroughly enjoyed reading this book and recommend it to anyone interested in where the current state of scientific discoveries in physics stands today.

DR. Lisa Randall is a master at explaining the complex research being conducted in theory and application regarding particle physics.
Her writing goes beyond mere explaination, as she has the unique ability to create a sense of wonder, excitement and urgency about the rather expensive research which is being carried out.
It is vital in our economically troubled times, because the public... the average Joe... can read (or listen to her eloquent interviews) and understand why this research is important. This creation of a understanding is important, because, in the end, these are the people who PAY for this research. Dr. Randall is the best when it comes to peaking the imagination and connecting with the public on these otherwise dry and esoteric areas of science.
There are elements in her writing that resonate with basic human needs: Hope, that we will find answers to questions that will make our lives better for the effort, and Faith, that although we may never be able to know everything, "the Truth IS out there" (X-file-esque), and it is worth the search.
Her book brought to mind Hamlet's words to Horatio:
"There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy."... or in this case: science.
Thank You Dr. Randall...!