The way this book is written seems to make it very, very difficult for me to understand.
I will see if I can make any sense of it by going through it slowly.
The author says this is the story of a specific atom: oxygen.
Part One: Divine Wind
Chapter 1: The Universe in an Atom
Talks about compressing the universe to the size of a baseball, but the chapter doesn't seem to go anywhere.
Chapter 2: The Right Stuff
Relates the collisions at the time of the very early universe with the collisions at CERN.
Introduces the idea of matter and anti-matter, and says the "lives of our atom" truly began at the moment when the amount of matter and the amount of antimatter in the universe
started to differ.
The story of cosmic background radiation (CBR) ... again.
Where did the background radiation come from. If matter/anti-matter had been equal, the only thing in the universe would have been energy. Instead, in a ratio of 1 to 1 billion: 1 proton to every 1 billion photons.
One particle of matter to every 1 billion "particles" of energy.
Had there been no protons, there would have been no atoms; there would have been no visible universe.
Why the asymmetry between matter/anti-matter?
Conservation of energy. If the universe started with no net electric charge in the universe, it has to remain with no net electric charge.
Gauge symmetry: explains why photons alone of all elementary particles have
no mass.
- gauge symmetry: a hidden symmetry in nature
- discovered in the early 20th century
- name of this symmetry coined by Herman Weyl
- gauge symmetry forms the basis of all four forces we know today
- two long-range forces: gravity, electromagnetism
- two short-range forces: strong and weak forces; operate at the nuclear level
But charge stability, alone, cannot explain the stability of matter -- see page 28 -29
One of the basic building blocks of nature is unstable: "free" neutrons -- half-life ten minutes
Mass of proton / neutron differ by 1 part in 1,000. Without this difference in mass, life could not exist. "The bad news" is this: this small difference in mass means neutrons are unstable and can decay.
A free neutron decays into: a proton, an electron, and an antineutrino.
Think about that: if neutrons did not decay ... would whatever there was after the Big Bang, that's where we would be? Stable universe with no changing? No life?
The free neutron is just slightly heavier than the sum of its parts, the proton, the neutron, and the antineutrino, and thus just barely able to decay into those particles.
Bottom of page 29, why the nuclear proton-neutron is stable. At the nuclear level, the neutron is slightly lighter than it would be if it were free.
None of the four known forces account for the stability of the proton. The author suggests that the stability of the proton is a "complete accident."
Lifetime of protons: proved, discussed, bottom of page 30.
Ends the chapter leading us to the next chapter in which the author says that recent discoveries in physics have explained how one can start with nothing (Big Bang) and with something (life as we know it today).
"What's more, this mechanism could preserve the long-term stability of matter today.
I think it is far to say that this is one of the great, largely unheralded, surprises in modern physics. And without it, our atom is literally nowhere.
Chapter 3
Time's Arrow
Sakharov asked the prescient question: how could the universe generate a matter-antimatter asymmetry if none existed at the beginning?
The nut: we are concentrating on an asymmetry between the fundamental particles making up the bulk of visible matter, protons and neutrons (and their anti-particles). Proton and neutrons are baryons. Sakharov realized there needed to be interactions that could independently change the number of baryons in the universe. [Baryons and mesons: made up of quarks; baryons made up of 3 quarks; mesons made up of two quarks.] That interaction
had to be very, very weak otherwise it would continue today.
More importantly, Sakharov determined that two additional subtle conditions must also exist:
a departure from "thermal equilibrium"
time had to have a direction
His three "ideas" languished. Physicists trying to sort out all the elementary particles being discovered in the 1970s.
But things moved quickly.
1973: quantum chromodynamics -- explains the strong force; analogous to quantum electrodynamics, the quantum version of electromagnetism.
The interaction (the strong force) between quarks gets weaker the closer they approach each other.
1975: while the strong force gets weaker with decreasing distance, the EM force and the newly understood weak force get stronger with decreasing distance. Perhaps these forces all converge --> grand unified theory (GUT).
1960's: the weak force that governs beta decay had been discovered.
Mid-1970s: physicists determined that the strong force and the weak force could be combined wiht the EM force into a simple mathematical framework. Many things explained, including why all elementary particles have electric charges that are integer multiples of the charge on the electron. The resulting theory: GUT.
The problem: this happened on a scale 15 orders of magnitude smaller than physicists could measure: not testable.
Page 43: the picture of "our" atom's birth. One extra quark produced in the early universe for every 1 billion quarks and antiquarks would be enough to account for all the matter we observe in the universe today: one billion photons were discovered in the cosmic radiation background for every proton in the universe.
Break, break.
That extra one quark was all the difference that the universe required for matter.
But has not been "proved" through tests. That's what they are doing in Japan with that tank of water deep underground: looking for a proton to decay.
Two quarks need to get close enough for the proton to go "poof." -- p. 46.
To get 10^30 protons: a tank of water with that many protons.
What signal do you search for: proton-decay --> two quarks convert into an antiquark and a positron.
Has never been seen.
By the 1980's large underground water experiments had ruled out the original GUT model and its predictions of proton decay.
So, physicists had to come up with another explanation. They came up with supersymmetry. But supersymmetry requires that every known particle in nature should have a new partner -- and none of these have been observed.
It turns out, those large water containers: useful for detecting neutrinos.
Neutrinos come from beta-decay (neutron decay) and by nuclear reactions inside the sun and stars.
1987: 19 neutrino events.
So, even though GUT has not been confirmed and supersymmetry seems a stretch, the author presses on, suggesting that the oxygen atom was created at the time of the Big Bang (or shortly thereafter).
Chatper 4
Nature or Nurture
A new accelerator at Brookhaven National Laboratory: RHIC -- relativistic heavy ion collider. Purpose: to look for quarks and see behavior of quarks that might have existed at the time of the Big Bang (or shortly thereafter).
Another reactor, near Williamsburg, VA, also looking for quarks.
After the Big Bang, by 10 billion degrees (cooled way down), essentially all the protons now existing had been formed -- before that, still quarks.
It took the universe about 1 second to cool from primordial baseball era (how this book began) to a temperature of 10 billion degrees.
Author calculates number of collisions:
- the sun's 5 billion years of burning: 10^55 collisions in each cubic centimeter
- the first second from Big Bang to 10 billion degrees: 10^89 collisions
At one millionth of one second old, free quarks were everywhere.
Impossible, so far, to create a single, isolated quark.
Page 54 -- quarks coming together -- definition of protons/neutrons arbitrary.
Chapter 5
Ten Minutes To Die
Chapter 6
One Hundred Million Years of Solitude
Chapter 7
Things That Went Bump In The Night
Part Two: The Voyage
Chapter 8
First Light
Describes nucleosynthesis due to gravitational collapse of massive protostars.
Big Bang (p. 100) had produced only:
- hydrogen (nucleus; P)
- helium (nucleus: P+N)
- "a dash of lighter elements": lithium (#3)
With gravitational collapse of star and nucelosynthesis:
- 10 million years of hydrogen burning
- 1 million years of helium burning
- 100,000 years of carbon burning
- 10,000 years of oxygen burning
- 1 single day, the rest: silicon --> iron (along the way deuterium, He-3, lithium, beryllium)
Chapter 9
A Pretty Big Bang
Page 122:
500 million years after the Big Bang: 8 of the initial protons and one (1) nucleus of helium (2N, 2P) have fused to form carbon.
So, again the numbers confuse me -- "8 of the initial protons and one nucleus of helium" fuse to form carbon? That's 10 protons and 2 neutrons -- 12 nucleons -- oh, that makes sense -- if the initial 8 protons flipped back and forth between protons and neutrons. Was this a typo? Did the author really mean to write 8 of the initial nucleons?
Then long discussion on carbon. How unique it is with ability to bond with other atoms.
This is amazing. In the expanding dust bubble, oxygen atoms created in the explosion combine with C to form carbon monoxide. Ten CO molecules exist in the gas cloud for every million or so hydrogen atoms. Nevertheless, carbon monoxide and water represent the dominant molecular components in the gas, next to hydrogen.
And then the process begins: first CO, then CO2; then methanol (CH3OH); and then ethanol (CH3CO2)OH; and, so on.
Carbon molecule even reacts to form CH2O (formaldehyde), when then reacts with ammonia and other nitrogen-bearing compounds on the dust surface until it finds itself part of the structure NH2CH2COOH -- glycine -- glycine is the lowest-carbon-number amino acid associated with self-reproducing life.
And we're only about halfway through the book.
On page 133, the author begins the story of the oxygen molecule: "The stage is now set for the ultimate formation of the atom we find today on Earth. Over the next 3 billion years -- the author doesn't specify when this began, but it appears it must have been about 500 million years after the Big Bang -- over the next 3 billion years, our carbon atom and the new helium atom, adrift in the evolving galactic sea of stars, will somehow find each other (C: 6P, 12 nucleons; He: 2P, 4 nucleons; oxygen: 16 nucleons).
Over the course of the first 5 billion years (p. 134) in the life of our galaxy, more than 100 million stars end their lives in supernova explosions....everything to the dustbin of history.
Author's sense of drama suggests that oxygen
was formed in the very last supernova whose products directly created our very own solar system.
A supernova explosion: most likely the third most abundant element would have been oxygen; followed closely by carbon (16 nucleons vs 12 nucleons). In some supernovae, carbon slightly beats out oxygen, as in the explosion that produced the carbon progenitor of our atom adrift in the galaxy. But as oxygen on average beats out carbon in the census of elements now existing in the universe, it is reasonable to assume that this last supernova we will focus on went with the flow, and produced more oxygen than carbon.
"Let us imagine that the oxygen atom that is the hero our story achieved its final form just in time....." Again, "just in time." Fortuitous, huh?
See last paragraph, p. 135, in which the author recapitulates the story:
- Big Bang: 16 particles
- in the first moments after the Big Bang: 13 particles, becasue one nucleus of helium formed (2P, 2N = 4 particles, becomes 1 "particle" -- 16 - 4 = 12 +1 =13 particles.
- a few hundred million years later: 7 particles, as a third helium is formed (12 nucleons - 8 nucleons = 4 particles plus 3 helium (6 nucleons): so 7 particles (4 free-nucleons; three helium nuclei)
- 5 particles quickly occur as the 3 helium atoms merge to become carbon
- in this configuration, 1 carbon and 4 hydrogen nuclei, they persist for billions of years
- finally, 2 particles, the nucleus of carbon and the nucleus of helium are brought together from originally disparate parts of the universe, with completely different individual histories, to make a single nucleus, the nucleus of oxygen.
