Review of New York Times Book of Physics and Astronomy
Dean, Cornelia (2013). Ed. The New York Times Book of Physics and Astronomy. New York: Sterling. 558 pages
It is Friday afternoon. I had nothing to do and was terribly bored. I did what I do whenever I am bored: go to bookstores, especially used book stores. I went to one and did what I normally do, browse through the science section. My eyes lighted on a book called the New York Times Book of Physics and Astronomy.
Wow, where have I been that I have not seen this one, I asked me. I picked it up and looked at the table of contents and it is divided into three sections: section one covered what we know about matter, section two covered application of what we know about matter to our lives and section three covered astronomy.
The book seemed like it would be an interesting read. The length, five hundred and fifty something pages, makes it long enough to keep me busy throughout the weekend, so, I took it to the cashier and paid for it and drove home.
At home I began reading it. I got done reading it this morning at around 5 AM. I decided to write a review of it. I found it necessary to review the book because I would like folks to read it. It is easy read; it has no mathematical equations cluttering it to discourage those disinterested in mathematics. Where possible, it appended the original writings of the giants of twentieth century physics. Simply put, it is a good review of twentieth century physics, so if you are interested in that science you ought to read it.
As you already probably know, physics is divided into two sections: classical physics and modern physics. Generally, classical physics covers everything that preceded 1896 when modern physics began. Classical physics covers mechanics, heat, light, electricity and sound, the type of physics you probably learned in secondary school.
Modern physics, also called quantum physics or quantum mechanics, began in 1896 when Rontgen discovered X rays. In the same year Henri Becquerel discovered radiation (certain atoms' nuclei, such as uranium and radium, decay and give off alpha particles). In 1897 J.J. Thompson, at Cambridge, discovered the electron.
The twentieth century began with Max Plank in 1900 discovering that light comes in units that he called quanta (in the 1600s Isaac Newton had actually said that light is in particles but Eugene Huygens said that it is in waves).
In 1803 Thomas Young's double slit experiment showed that light is wave and affirmed Huygens view. Physics saw light as wave until Plank showed that light is also particles.
In 1905, Albert Einstein showed that light is in particles; his paper on the photo electric effect of light is actually what won him the Nobel Prize, not his special or general relativity.
General relativity was not proven as science (is it science?) until Arthur Eddington, the early twentieth century preeminent British astronomer, observed a near total eclipse in 1919 and that seemed to show that space do, indeed, as Einstein argued, curve and that space and time are not separate but are one continuum.
In the meantime, Pierre and Madam Curie studied uranium and radium and improved on Becquerel's writings on radioactivity. Uranium, number 92 on Chemistry's Periodic Table, is the heaviest naturally occurring atom with 92 protons, 92 electrons and 146 neutrons. Because it is bulky and unstable it decays, radiates. Over millions of years, uranium decays and, in the process, transforms to other elements.
The New York Times book of physics section one took the reader through the momentous discoveries of the first forty-five years of the twentieth century.
The century began with Plank's studies of the radiation emitted by hot black bodies; his discovery that radiation, light is in units' that he called quanta. In 1905 Einstein validated Plank's discovery by showing that light has particles that knocked off electrons from hot bodies.
In 1911 Ernest Rutherford showed that the Greek Democritus' conception of atom as the final indivisible unit of matter, and Dalton who resurrected that concept of atom, were not quite correct when they said that the atom is the smallest indivisible unit of matter. Rutherford showed that the atom has an inner core that he called nucleus (that contained protons).
Later, in 1932, Rutherford's star student, James Chadwick showed that the nucleus also has a neutral particle that he called neutron.
Thus, we now know that the atom is composed of a nucleus that has protons (which are electrically positively charged) and uncharged neutrons and negatively charged electrons circling the nucleus.
All elements are atoms; the difference between elements is the number of the particles inside them. Hydrogen, the smallest atom, for example, has just one proton in its nucleus and one electron circling it (except in its isotopes where there may be one or two neutrons in the nucleus). Helium has two protons and two neutrons in its nucleus and two electrons circling it; we go down the periodic table by adding the number of protons and neutrons in each element's nucleus and the number of electrons circling it.
Scientists, in laboratories have invented about 20 additional elements, in addition to the 94 naturally occurring elements.
This book gave us narration of when discoveries about the atom were made and who made them. It then focused on the giants of quantum physics.
In 1913 Neils Bohr showed that electrons circled nucleus. In 1923 Louis Broglie showed that electrons behaved like light in double slit experiments (has wave and particle functions).
In 1925 Werner Heisenberg, in his matrix equations, posited his uncertainty principle; the idea is that you can ascertain the position of the electron or its velocity inside the atom but not both at the same time; it is either you see one or the other but not both at the same time.
In the same year Erwin Schrodinger reached the same conclusion as Heisenberg through his wave equations.
Paul Dirac, building on Max Born's discoveries, looked at the nucleus more closely and realized that for the equations to balance that during nuclei decay a particle he called neutrinos had to be emitted in addition to the alpha particles that the curie's had posited.
In 1927 Bohr posited his concept of complementarity; it states that light (and electrons) behave as either wave or particles but that you cannot see both behaviors at the same time; if you focus on one aspect of it you will not see the other. If you study light as particles you will not see it as wave and if you study it as wave you will not see it as particles. The idea is that light behaves as the observer wants it to behave.
If you are studying particles where is the wave function of light? He posited what he called superposition; particles are in a place that you cannot see; it is only when you want to see them as particles that they are collapsed from their wave function to particle functions for you to see them.
In the 1930s it was discovered that since in nature some elements decay, albeit it over millions of years, that we can artificially decay them. Enrico Fermi, Lise Meitner, Otto Hahn and Strassman posited ways to do so. Essentially, it was done through using neutrons as projectiles to strike nuclei until they break up.
Protons and neutrons are held together in the nucleus by the strong nuclear force and decayed by the weak nuclear force; the electromagnetic force keeps electrons attracted to nuclei (gravity operates at the macroscopic level, keeps large objects attracted to each other; example, the sun and its planets are held in place by gravitational force).
Bombarding the nuclei of uranium with neutrons (projectiles) accentuated the decay of the nuclei. Neutron bombardment of uranium nucleus splits the nucleus and releases energy (radiation). This is what is done in nuclear fission (atomic bombs).
In hydrogen bombs, on the other hand, two stages have to take place; first, we split uranium nuclei via neutrons and produce tremendous heat and radiation; that heat approximates the heat inside stars and forces two protons to fuse and form the nuclei of helium atom; as inside stars, this fusion of protons produces enormous heat and radiation hence the devastating effect of hydrogen bombs.
Einstein thought that Bohr's complementarity principle smacks of mysticism, not physics, and vehemently opposed it. To disprove it, along with his friends, Podolsky and Rosen, Einstein performed a thought experiment in 1935. His goal was to show that physics operated on deterministic rules. What he ended up discovering is that when two particles are entangled and separated that when you stimulate one the other feels stimulated regardless of its distance from the other.
John Bell, in 1962, proved this to be true, not just a mathematical possibility as Einstein had envisaged. In 1982 Alan Aspect experimentally entangled particles and separated them and then stimulated one and the other felt stimulated; it appears that there is no space and time between entangled particles, for the responses of both particles are instantaneous. This occurrence challenges our notion of locality; it implies that either particles travel beyond Einstein's speed of light (in vacuum 186, 300 miles per second) or all particles are in one place!
In 1957 Hugh Everett (and his doctoral adviser, John Wheeler, at Princeton University), in responding to Bohr's idea of superposition argued that there are many worlds.
When particles are not studied they are, he said, in other worlds; when we want to study them they come to be seen in our world. This idea led David Deutsch of Oxford to posit what is now called multiverse, the idea that there are infinite universes.
Essentially, section one of this book took the reader through the discoveries that we now call quantum physics. This is useful piece of information.
Section two of the book is devoted to applied physics; we apply the discoveries of physics in technology and use them to better our lives.
Just about most of the things we now use are the results of our twentieth century understanding of the nature of atoms (matter and antimatter). The book took the reader through a narration of when some of the more well-known items we now use in our daily lives were made.
Transistor radios, Television, Computers, Internet, Wireless cell phones etc. are the products of quantum mechanics. Our understanding of the atom, hence matter has given us our present incredible technology.
In medical science, doctors make routine use of X rays, Cat Scans MRI; surgeries are often done with lasers (ionized atoms, electrons).
Society derives some energy from nuclear fission (in nuclei silos uranium nuclei are split, energy released, captured and transformed to electrical energy).
In the eighteenth and nineteenth centuries the discoveries in mechanics, heat, light, sound and electricity led to the steam engine and machines that made the industrial revolution possible.
The age of industrialization was the product of classical physics whereas the age of electronics that we live in is the product of our understanding of how electrons and other particles behave. Unfortunately, the knowledge of atoms has led to nuclear weapons that could end life on planet earth.
Section three of the book essentially showed us how astronomers used Newton's gravity and its reworking in Einstein's special and general relativity and quantum mechanics to conceptualize their understanding of the origin and nature of the universe.
Alexander Friedman, in 1922, building on Einstein's general relativity, showed mathematically that the universe is expanding.
If the universe is expanding then it must have begun in one spot, reasoned the Belgium physicist, George Lemaitre. He posited the cosmic egg origin idea of the universe. The universe began in one spot and expanded.
In 1929 Edwin Hubble used his telescopes to show that the galaxies are indeed expanding away from each other.
George Gamow in the 1940s experimentally showed that indeed the universe came into being in one spot; all things were in a state of singularity and subsequently exploded and the universe came into being.
Fred Hoyle, an English astrophysicist, disagreed with Gamow, and posited what he called the steady state universe. In trying to make fun of Gamow, in a BBC broadcast, he called Gamow's ideas on the origin of the universe Big Bang. That derisive term stuck!
Today, it is said that 13.8 billion years ago, out of nowhere a particle of light came and got incredibly hot and exploded. It shattered into photons (particles of light).
The photons immediately combined into electrons (matter) and quarks (matter). Quarks combined into protons and neutrons.
Anti-matter was also formed, such as anti-electrons (positrons), anti-quarks, anti-protons, anti-neutrons and anti-atoms. Matter and anti-matter supposedly attacked each other and ought to have annihilated each other and ended the formation of a matter based universe. Apparently, for every 1 billion particles of anti-matter formed a billion and one particles of matter were formed, so that when they attacked each other, instead of returning themselves to radiation some matter was left to continue the evolution of a matter based universe.
We shall skip the minutia of the processes that resulted in the production of matter and anti -matter (over 100 particles have been discovered, all came into being at a point or the other as the transformations of photons into matter was taking place; I am talking about mesons, leptons, bosons etc.).
By the second minute after the big bang occurred came into being photons, protons, neutrons and electrons. By the end of three minutes after the origin of the universe, Steven Weinberg tells us that protons and neutrons combined to form nuclei.
The incipient universe kept expanding and cooling down. Alan Guth said that it expanded at a speed higher than the speed of light hence escaped the gravitational pull to collapse back to singularity and end the universe; he called this period inflationary period.
The early universe was plasma, a soup of nuclei, photons and elections. 400, 000 years later, nuclei captured electrons and atoms (hydrogen, Helium, Lithium etc.) were formed.
The universe became a sea of hydrogen and helium. A few million years later space occurred in the sea of hydrogen. Each clump of hydrogen separated from others.
Each clump of hydrogen gas was acted on by gravity; it was pressured inwards; this pressure generated enormous heat in its core. The nucleus of hydrogen (one proton) captured another hydrogen nucleus (proton); that is, two protons combined to form a nucleus with two protons and two neutrons and two electrons circling it hence the formation of helium.
Stars are caldrons of hydrogen in whose core hydrogen fuse into helium. As stars age they run out of hydrogen and begin fusing other elements, such as carbon; when the nucleosynthesis process reaches iron the star increases in size and blows up (in supernova).
Given the enormous heat accompanying supernova, elements higher than iron are formed and shattered into space (to form nebulae, star dust).
From star dust of shattered massive stars new stars and planets are formed. Our sun and its nine planets were formed from old shattered stars 4.5 billion years ago.
Each star has a life cycle; first, it fuses hydrogen into helium and in time exhausts its hydrogen and fuses other elements and in time explodes and dies.
When a huge star explodes its outer parts are discarded into space but its inner core implodes to form either black holes or neutron stars.
In black holes nothing, not even light, can escape from their event horizons. In neutron stars all matter is crushed into neutrons and the star spins at mind dizzying speed.
There are many types of stars, including quasars, pulsars, binary stars etc.
Our universe is expanding rather rapidly. Why is it expanding so rapidly? In the 1990s physicists posited what they called dark energy. Dark energy is supposed to compose 73% of the universe and expands the universe. Dark matter (23% of the universe) helps gravity in holding the stars and galaxies together.
Astrophysics posits that in trillions of years in the future, the over 200 billion galaxies in the universe (each galaxy contains over 200 billion stars, so is our Milky Way galaxy and our nearest galaxy, Andromeda) and their stars would be so far from each other that they lose heat and experience entropy, run down. Stars and planets would decompose into the elements that composed them and the elements would decay into particles and all the particles eventually decay to radiation (light).
The universe that began in heat ends in cold, Big Chill.
Part three of the book took us through the discoveries made in astronomy during the twentieth century, plus those made in classical times, such as Galileo's, Newton's, Huygens's and Kepler's.
This section devoted too many pages to what is called Superstrings theory. Strings theory posits that particles are like strings on a violin.
Enthusiasts of strings theory seem to enjoy speculating on the nature of phenomena; they have posited such ideas as Branes, ten dimensional universes, universes branching out of others and so on; all of them mere conjectures and not one proven as a fact.
I tend not to pay much attention to strings hypotheses for they seem like mere science fiction. That been said, this section gave a useful rendition of where astronomy is at this point in time.
On the whole, the book is a useful summation of where modern physics and astronomy are, today; it is a useful two days read; I highly recommend it to anyone interested in science and technology.
October 23, 2016