The First Three Minutes - Steven Weinberg # Review

This book in cosmology should have been read long back - particulary if one has read some books on Big Bang and particle physics.The author chronicles the very early history of the universe while describing the underlying physical concepts. In view of epoch experiments to be conducted with new Large Hadron Collider (LHC), during October 2008 at CERN, the European Organization for Nuclear Research. The LHC will create the conditions of less than a millionth of a second after Big Bang when there was a hot soup of tiny particles called quarks and gluons. This was one of the fastest read books by me as most of the concepts were already known.

The most intriguing chapters in the book are the First Three Minutes (Chapter 5) and First One-Hundred Seconds (Chapter 7). Standard model of cosmology proposes that the universe is made of , well known, four fundamental physical forces; weak nuclear force, strong nuclear force, electromagnetic force and gravitational force. When the universe was 10(e-43) seconds old (the first moment of the universe), the temperature was about 10(e32) K, and all the four forces were considered unified. (Just like the postulates of Qunatum Mechanics, where the first one is that the Universe was a smooth flow of Energy in the beginning, when matter came later!- but holds still good)

The author, being a Nobel Laureate, is one of the pioneers in this field of research and  proposed the existence of unified of weak and electromagnetic forces for which he was awarded Nobel Prize. When the universe was above the critical temperature of 3*10(e15)K, these two forces were symmetrical and had the same strength, and the symmetry broke as the cooling of the universe decreased the heat below the critical temperature. It is during the symmetry breaking epoch matter acquired the mass through Higgs Bosons. Between the first 10(e-43) to 10(e-36) seconds of the universe's birth, all the four forces were unified, but after 10(e-36) seconds strong nuclear force separated and the universe went through an inflationary epoch (sudden exponential expansion) between 10(e-36) and 10(e-32) seconds.

Reheating of the universe between 10(e-32) and 10(e-12) seconds resulted in the production of hot quark-gluon plasma. Particle interactions in this phase were energetic enough to create large numbers of W bosons, Z bosons and Higgs bosons, which are most the fundamental forms of matter. There after when the universe was about 10(e-12) seconds, the production of W and Z bosons stopped. This was followed by the quark epoch, between 10(e-12) to 10(e-6) seconds, the four natural forces took the form that is prevalent in the current universe. This was followed by the Hadron epoch, between one microsecond to one second, quarks started binding together to form hadrons (protons and neutrons), which are held together by the strong force. One second after the big bang, the lepton epoch began when neutrinos stopped interacting with other forms of matter. Leptons includes; the electron, the muon, the tauon (tau particle), and the associated neutrinos (electron neutrino, muon neutrino, and tau neutrino). Leptons and anti-leptons were annihilated except for a small residue, and this was followed the photon epoch where photons dominated the universe. Nucelo-synthesis of helium occurred during the first 3 to 20 minutes; after about 380,000 years after the Big Bang the temperature of the universe fell to the point where nuclei could combine with electrons to create neutral atoms. As a result, photons no longer interacted frequently with matter, the universe became transparent and the cosmic microwave background radiation was created. Then we were to coin the formation of Amino acids after certain drastic reactions and the events unfold.

During the very first minute, when the universe was in thermal equilibrium, the numbers and the distribution of all particles were determined statistically and not by prior history; cause - effect relationship did not exist! The universe started with equal number of protons and neutrons, and the conversion of neutrons to protons (that form the basics of Nuclear Chemistry like photonuclear reaction) occurred through its interaction with; electrons, positrons, neutrinos and anti-neutrinos. Hydrogen and helium were produced in abundance prior to the evolution of galaxies and stars. Stars evolved using hydrogen as a nuclear fuel to generate energy and their existence.

The detection of background cosmic microwave radiation (CMR) in 1965 by Penzias and Wilson, was one of the most important discoveries of 20th century. Other chapters give a historical and simplified development that lead to the prediction of of CMR, a remnant of the big bang, and also history of cosmological theories of nucelo-synthesis of heavier elements.

This book is a must read for all the undergraduates in Physics and Chemistry. Recent advances in cosmology might have rendered some information contained in this book as obsolete. Nevertheless, this book is very well structured with useful glossary of physics terms and concepts and a mathematical supplement.

Your Brain is a Time-Machine - The Neuroscience and Physics of Time - Dean Buonomano #Review

                         

The brain is an illusion factory! Well, this is how the author considers before completing his thoughts about the brain and its perceptions. Time and activities based in life are aptly considered by this author to prove how our brain is a machine that has its own way of considering events and classifying them.

The book begins with a summary of the psychology, philosophy, pharmacology and physiology of time. The author has an excellent grasp of the issues at stake and the importance of doing research on these topics. How do drugs affect our time perception, and what does that tell us about the brain? How can neurons or neural networks detect measure time?  

The book also describes a bit on the physics of time and the philosophical implications. Does time even exist, or is it (like many other things), a persuasive  illusion that the brain construes to give us an advantage in evolution? Is present-ism (only the ‘now’ exists) or eternal-ism (time is another dimension and ‘now’ is to time what ‘here’ is to space) the correct model of the universe? 

The act which we take simple has been explained in significant way: that when a baby begins to look at his mother, he views it along several angles at different times and sometimes larger (when she is close) only to stitch these pictures for composing an ultimate face in its database.  This way every one gathers data and webs a new picture or scheme of things in life. The brain records the statistics of what we see, hear and experience and uses patterns to make sense of the world around us. That the brain is an expert in 'scavenging' the information is an important point delivered.

Pavlov's dog, whose stomach acidity was measured at a constant time is used to tell how body behaves with regular time-bound activities.  This is because the brain creates the sense of time as it cannot be physically measured. We, thus the author says, do create 'future' and help ourselves comfortable with the dimension of time.Going along the nuances of time the author describes the relativity with time: "A watched pot never boils" and time flies when you have fun. Chronostasis is considered as stagnant time when you are not enjoying the physical world.

There is this mention about the 'slow motion' in life. People's ability to react quicker and perceive events is compared with a CPU processor, where the processor is designed to withstand a certain over-optimised speed. Likewise the brain enters the 'over-clock' mode.There is more mention about theory of relativity and a good explanation to it with a few examples. That a special relativity is called so because we can ignore the influence of 'gravity' is quite a new approach to explain the same.

Finally an attractive quote that I found would make a few people go sarcastic is here:  There is a theory which states that if ever anyone discovers exactly what the universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable.The reason we say that humans have free will is because we can't predict what they will do.The brain—the most complex dynamical system in the known universe—tells, represents, and perceives time in multiple ways. In this book of popular science, neuroscientist and author Dean Buonomano investigates the intricate relationship between the brain and time with ample examples. 

In the last chapter, the author cites the core issues. He ponders whether animals plan for the future and whether they reflect on the future in the same way that we do. There is this meeting with the Piranhã tribe who, according to an anthropologist, lived with them, lives in the here and now. The author also takes on free will. If time is just another dimension that we can, at least in theory, travel across, then that should logically mean that everything that is going to happen has already happened which presumably means there is no free will. Free will, the author suggests may only be the feeling associated with making decisions - just like we feel pain when we get painful stimulation. 

Free will, consciousness, space-time, and relativity from the perspective of a neuroscientist, drawing on physics, evolutionary biology, and philosophy, 'Your Brain Is a Time-Machine' reveals that the brain’s ultimate purpose may be to predict the future, and thus that it is a time machine.