340                        The Bible According to Einstein

The ninth book of Creation, called

Deuteronomy⁴⁰

And so the tiny excess of quarks over antiquarks had left miniscule amounts of quarks surviving in the cosmic sea. And these few quarks were now confined inside the proton and the neutron. So thus it be. The Universe was full of neutrinos, antineutrinos, electrons, positrons and photons. But only one-billionth of the cosmic sea was made of neutrons and of protons.

In the next three minutes
would transpire a chain of nuclear events.

     Now this is the story of Big Bang nucleosynthesis. The story is full of accidents. It has seven episodes. It describes the creation of the lightest elements.

Episode I: The Energetic Cosmic Sea

The time was one-hundredth of a second – thy Universe had existed for one-hundredth of a second. The cosmic sea was agitating wildly. Subatomic particles bounced off one another via strong, weak and electromagnetic interactions. In colliding, they exchanged their energy and their momentum. Thus the particles were "in contact" through their thermal motions and their interactions.
     Particles underwent subatomic transformations. Photons combined and disappeared, and in their place electrons and positrons suddenly appeared. Positrons and electrons self-destructed into photons. Neutrons and neutrinos collided off of one another, ending up as protons and electrons. Protons and electrons smashed and reemerged as neutrons and neutrinos. Neutrons and positrons met and metamorphosed in particle alchemy as antineutrinos and as protons. Antineutrinos and protons underwent transcendental transformations into positrons and neutrons. But among all these particle conversions, those involving neutrinos proceeded relatively slowly; the others proceeded rapidly.⁴¹
     Now the Universe’s temperature in Kelvins was a hundred-billion.⁴² In these hot conditions, there was a thermal equilibrium among the nucleonic states. And as a consequence, the numbers of protons and of neutrons were essentially the same – the thermal cosmic sea had so much energy to give that the protons and the neutrons were created and destroyed at equal rates.

____________________

⁴⁰ The physics of this book is discussed in the New Testament Book of Nuclear Physics.
⁴¹ Neutrinos only interact through the weak force.
⁴² This is about a thousand times hotter than at the center of the Sun.

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Episode II: Protons Come to Outnumber Neutrons

Now time advanced and temperature decreased. Soon the protons numbered more than neutrons, for the thermal cosmic sea had less energy to give and gave it to the lighter particles: So protons, being a little lighter than the neutrons, were produced more easily. So neutrons, being heavier than protons, were destroyed more easily. The neutrons disappeared through sacrifice by giving up their mass in making lighter particles and energy. And thus it came to pass that, when the Universe was one second old and the temperature was ten-billion, there were six times as many proton particles as neutrons.

Episode III: Nucleons Cease Their Subatomic Transformations

Since Episode I, the width of the Universe had grown tenfold. The volume of the Universe had increased a thousandfold. The temperature had dropped tenfold. And the density of particles had declined a thousandfold.
     As the Universe got cooler, the weak interaction grew much weaker. Since space had pulled the particles apart, particles encountered one another less: Collisions among the nucleons decreased. So rare were these collisions and so feeble was the weak force that the proton-neutron particle conversions ceased. At this moment, there were six protons for each neutron.

Episode IV: Neutrinos Decouple and Escape

Now the neutrinos, which only interact through the weak interactions, no longer interacted, for the weak force was too weak. Henceforth and forever, these neutrinos would move freely through the Universe. The story of these particles would be incredible. They would become a cosmic non-interacting relic, a ghost in space and of the past. For eternity would they fill three-space. Though omnipresent, they would be for the rest of time invisible.

Episode V: Positron Annihilations

The age of the Universe increased tenfold. The time was ten seconds. The temperature of the Universe dropped threefold.
     And the cosmic sea could no longer hold the light charged leptons. Thus electrons and positrons annihilated into photons, as the primordial sea purged itself of positrons. There was a tremendous flash of gamma rays. The Universe exploded inside itself as a matter-antimatter bomb once more. This would be the last such matter-antimatter bomb.
     Now the tiny excess of matter over antimatter, which had existed since Grand-Symmetry destruction, remained as a tiny excess of electrons over positrons. And since not every electron found a positron with which it could annihilate, minute amounts of electrons consequently stayed. But the Universe was basically charge-neutral: The number of electrons which survived equalled the number of protons in the primordial heat bath, though this number was relatively small – in the cosmic sea, there was but one electron for every billion photons. Thus, in the dense hot-gas bath of photons, there was a dilute plasma of positive and negative electric charges in the form of minute protons and electrons. And all this took place in the arena of the Big Bang aftermath.

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Episode VI: The First Deuterons and First Nuclei

Now from time to time, a proton and a neutron merged and formed a deuteron. So in the cosmic sea were traces of deuterium.
     Now the primordial sea had a strong natural tendency to make helium-four, for helium-four was the most stable of the lighter nuclei. But rarely did two protons and two neutrons come together to make such helium directly. Instead, miniscule amounts of helium-three were manufactured when a proton struck a deuteron or when a neutron and two protons met by chance.

Episode VII: The Light Nuclei Are Made

Three minutes slipped away. During this long interval, in which thy Universe aged a dozen-fold, a fraction of the neutrons did decay – when such a neutron disappeared, an antineutrino, an electron and a proton in its place appeared. And so it came to pass that there were seven protons for each neutron.
     The temperature dropped further – it was a billion. At this lower temperature, particles swam the cosmic sea with lower energy. And since nucleons more slowly moved, strong forces made them stick together when nucleons encountered one another. Thus in "nuclear matrimony" did a neutron and a proton merge to make a deuteron. But the deuterons, which were being readily produced, disappeared at almost equally rapid rates, for instantly did they combine to forge the heavier light-nuclei: And for example, in the heat bath gas, a deuteron and a deuteron merged to make a proton and a tritium. And nearby, another deuteron and a neutron stuck to form another tritium. One such tritium and a deuteron instantly were drawn together by the strong force, and after the two nuclei had merged, a neutron and a helium-four were forged. Elsewhere in the heat-bath gas, one deuteron banged into another deuteron, producing a neutron and a helium-three. In still another place, a deuteron and a proton merged and directly made a helium-three. Then a helium-three and a deuteron collided and emerged as a proton and a helium-four. Elsewhere in the cosmic sea, two deuterons directly forged a photon and a helium-four. And all of these processes proceeded everywhere in space.
     And the Universe blew up inside itself as an enormous fusion bomb. And almost all the neutrons ended up in nuclei of helium-four. And so the neutrons became enslaved in nuclei. And miniscule amounts of lithium-seven were fabricated, for a helium-four and a tritium, on rare occasions, made a photon and a lithium-seven.

And with a few embellishments,
in seven stages and three minutes,
at a temperature of a billion Kelvins,
Nature made the lighter elements.

The Old Testament                                       243

Chapter II: Taking Count

And what was the nuclear score? For weight, one can ignore the leptons and the photons, for they are relatively light. By weight, seventy-six percent of matter was in protons and twenty-four percent was in the form of helium-four. All neutrons were in helium cores. And as for the other elements, by number, deuterium was one part in ten-thousand, helium-three was ten parts per million, and lithium-seven was one in ten-billion.
     Now during the three-minute epoch of nucleosynthesis, the width of the Universe increased a hundredfold. And the particle density dropped a millionfold. And the energy density of the Universe fell a billionfold.
     The primordial cosmic egg, which had been so round and perfect, had been broken. And its contents had been spilled and scattered throughout the vastness of thy Universe – the beginning of the process toward chaos had commenced.

Humpty Dumpty had a great fall.