- 出版社: Basic Books; 2 Updated (1993年8月18日)
- 平装: 224页
- 语种： 英语
- ISBN: 0465024378
- 条形码: 9780465024377
- 商品尺寸: 13.3 x 1.6 x 20.3 cm
- 商品重量: 209 g
- 品牌: Basic Books
- ASIN: 0465024378
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The First Three Minutes: A Modern View Of The Origin Of The Universe (英语) 平装 – 1993年8月18日
"Science writing at its best." -- --Martin Gardner, New York Review of Books
My second reading of the book occurred this year, 2017. I wanted to re-read this book. Between those years ( 1977 and 2017) much has changed,
both in my education and within the context of cosmological research. First, in terms of my education I have had the pleasure of studying from Steven Weinberg's textbooks (starting with Gravitation and Cosmology and ending with his Lectures On Quantum Mechanics); In terms of Cosmology I am both young enough--- and old enough--- to have witnessed the birth of string theory, the birth of inflation theory, the discovery of Higgs Boson and the discovery of Gravitational Waves. And, now, of course we have Dark Energy to contend with ! Be that as it may, Weinberg's The First Three Minutes is truly the first serious introduction I ever read. And, it (that is, the book and Cosmology) still excites me !
Let us quote some interesting lines:
(1) "...an explosion which occurred simultaneously everywhere, filling all space from the beginning, with every particle rushing apart from every
other particle." (page 5). Think about how often this concept, this "Big Bang" gets muddled in the classroom. Many have failed to read this line !
(2) " However, even if it is eventually supplanted, the standard model will have played a role of great value in the history of Cosmology." (page 9),
Think about how often many fail to underscore the provisional nature of the theories ! Weinberg is well aware of limitations to physical theory.
(3) " As often happens in Science, this argument can be used both forward and backward," and " if the universe is isotropic around every point,
it is necessarily also homogeneous." ( page 23). And, there you have a master educator presenting subtleties. Kinematics occupied
the first thirty pages, dynamics (Newton and Einstein) starts with page 31...and, we now know that this needs emendation:
(4) " The galaxies are not rushing apart because of some mysterious force that is pushing them apart, rather, the galaxies are moving apart
because they were thrown apart by some sort of explosion in the past." ( page 35). This next line, causality:
(5) " No signal can travel faster than the speed of light, so at any time we can only be affected by events occurring close enough so that a ray
of light would have had time to reach us since the beginning of the Universe." ( page 41). The concept of Horizon thus introduced.
(6) Chapter Three--Cosmic Microwave Radiation Background--is my favorite. Weinberg's terminology " background radio static " is apt.
Amusing Weinberg writes "degrees Kelvin," which, I believe is an abuse of terminology (one need not write 'degrees' ). We read:
"...although in a sense the Universe was expanding very rapidly at first, to an individual photon or electron or nucleus, the expansion was taking
plenty of time---time enough for each particle to be scattered or absorbed or re-emitted many times as the Universe expanded. (page 55).
It is here where the concept of Thermal Equilibrium is first introduced. ( It is here where the topic of statistical mechanics first charmed me !).
We learn that strictly speaking "temperature" is only defined for thermal equilibrium. And, " it is crucial to the argument of this book that the
Universe has once passed through a state of thermal equilibrium." ( page 56). So much Physics in that one line !
(7) Photons, Black-Body Radiation, Stefan-Boltzmann Law, Planck's Energy Quanta: Chapter Three is a veritable qualitative course in Modern Physics. And who do we meet, but our friend Rainier Weiss....now, the 2017 Nobel Laureate in Physics.
(8) " Eventually, as we look farther and farther back into the history of the Universe, we come to a time when the temperature was so high that
collisions of photons with each other could produce material particles out of pure energy." There, our first hint of quantum field theory.
We read: " to every type of particle in nature, there is a corresponding antiparticle," ( page 82 ). Next up, " the balance between the gravitational
field and the outward momentum of the contents of the Universe that governs the rate of expansion." Finally, the conserved quantities of
Electric Charge, Baryon Number, and Lepton Number. ( described page 92). Thus, Chapter Four, introducing particle physics qualitatively.
(9) The first hundred pages have been preparation for Chapter Five: The First Three Minutes. It is here where it is all put together, assembled.
Weinberg discusses Neutrino Background, among other things. He concludes with this: " the appropriate response to such uncertainties is not
to scrap the standard model, but rather to take it very seriously and to work out its consequences thoroughly--if only in the hope of turning
up a contradiction with observation. ( page 120). Spoken like a true scientist.
(10) " The present Universe is so cold that the symmetries among the different particles have been obscured by a kind of freezing; they are not
manifest in ordinary phenomena, but have to be expressed mathematically, in our gauge field theories." ( page 149). Another clue !
Well, the book is done. There is an eight page Glossary ( always helpful) and ten pages of mathematical supplement.
Topics Of The Supplement (algebra and introductory physics utilized):
Doppler Effect, Critical Density, Expansion Time Scales, Black-Body Radiation, Jeans Mass, Neutrino Temperature and Density.
The supplement could be utilized for teaching, it being merely ten pages, the discussion is easily amplified ( that is, work out the math !).
References for further reading concludes the book: Included among them, texts which every physicist should study--
(1) Gravitation by Misner, Thorne, and Wheeler,
(2) Large Scale Structure of Space-Time, by Hawking and Ellis, and,
(3) Weinberg's own Gravitation and Cosmology (and now, his Cosmology Text).
But, back to The First Three Minutes--plenty enough here to keep one thinking !