Modern Physics Theory of the Start

Who knows if this affects people? In another field, nuclear weapons and places like the Hanford Works and Savannah River Plant, amazing ideas definitely influence average people. In the area of cosmology, the average person has no concern about it, and it doesn't affect one's security. These ideas have been in popular books for 43 years. Any person who first encounters the idea of something important happening in 10^-32 seconds is incredulous, but I read it over and over, and the authors take it seriously. So here is some of this material, the part that is hard to find or hard to interpret.

https://www.forbes.com/sites/startswithabang/2017/03/24/how-big-was-the-universe-at-the-moment-of-its-creation/#71f9ef624cea

Here are some fun milestones, going back in time, that you may appreciate:

The diameter of the Milky Way is 100,000 light years; the observable Universe had this as its radius when it was approximately 3 years old.

When the Universe was one year old, it was much hotter and denser than it is now. The mean temperature of the Universe was more than 2 million Kelvin.

When the Universe was one second old, it was too hot to form stable nuclei; protons and neutrons were in a sea of hot plasma. Also, the entire observable Universe would have a radius that, if we drew it around the Sun today, would enclose just the seven nearest star systems, with the farthest being Ross 154.

The Universe was once just the radius of the Earth-to-the-Sun, which happened when the Universe was about a trillionth (10^-12) of a second old. The expansion rate of the Universe back then was 10²⁹ times what it is today.

Ethan Siegel I am a Ph.D. astrophysicist, author, and science communicator, who professes physics and astronomy at various colleges. I have won numerous awards for science writing…

https://www.physicsoftheuniverse.com/topics_bigbang_timeline.htmlhttps://www.physicsoftheuniverse.com/topics_bigbang_timeline.html

Image above: for the full image, look at the Forbes web site. Before July 2020, I have not seen such a graph. Using the straight-line nature on a log-log plot, I came up with this formula:

log ( size of universe in light years ) = 0.5 log ( universe age in years ) + 4.7

Using this formula, and Lawrence Krauss' ATOM 2001 Back Bay Books p. 59, here are some events.

Time Line

10^-12 second from Big Bang diameter 80 million miles, about the current Sun-to-Earth distance. This is the electroweak epoch, to be followed by the quark epoch. For other epochs, see Wikipedia, Chronology of the universe. Also https://www.physicsoftheuniverse.com/topics_bigbang_timeline.html.

Early on, don't worry about so much matter crammed in too little space. Just know that most of what is there is energy, which can pack in much tighter than matter. Later, energy changes into matter, when there is more room.

1 second old 10 billion degrees Kelvin diameter 10 light years density 400,000 the density of water Note that matter and energy have far outpaced the speed of light, since the speed of light goes 186,000 miles in one second, merely 22% of the current size of the Sun. Whether this is from "inflation," I don't know. The density at 1 second can be compared to the present average density, 4 hydrogen atoms per cubic meter.

225 seconds 3 billion degrees Kelvin diameter 132 light years hydrogen nuclei (single protons) had been the only matter around, now some deuterium forms, but it is too hot for helium nuclei. 225 seconds is about the "first three minutes," see Weinberg's The First Three Minutes 1977. This is before Guth's inflation idea, 1981. Within another minute, more cooling allows helium-4 nuclei to form, and all free neutrons find homes there.

Lawrence Krauss in ATOM p. 62: Helium was thus only formed in the Big Bang because the binding energy of protons and neutrons into deuterium took precisely the value it did.

1 year old 2 million degrees Kelvin diameter 100,000 light years

100 years diameter 500,000 light years gamma rays have cooled to X-rays. Intense radiation pressure disrupts any gravitational clumping. Everything is uniform, featureless. No clumping due to gravity.

380,000 years old temperature the boiling point of iron diameter 31 million light years Before, everything is plasma and very conductive, radiation cannot penetrate conductive material. Now, loose electrons and protons combine into neutral atoms ("recombination"), mainly hydrogen and helium, universe becomes transparent to light and all radiation. Cosmic Microwave Background shines through, though it is much hotter at this time than 3 degrees Kelvin.

It is odd that cosmologists think they have sure knowledge, to two significant digits, of this 380 thousand years. It is 380, not 300, not 400.

The idea of radiation not penetrating conductive plasma also crops up in atom-bomb explosions. There is a visible (from dozens of miles away) double pulse, the first light pulse being the first millisecond of the expanding plasma. But the outer limits of the fireball are overtaken by a hydrodynamic shock wave, an opaque ionized shock front, which is cooler. Electromagnetic radiation and 99% of the thermal energy are bottled up. The fireball is expanding faster than the speed of sound and it is cooling. After about a second, the shock wave weakens and lets energy escape. The second light peak is seen.

For a long time, all matter is uniformly distributed. There are no planets, no stars, no galaxies. There is gravity, but no volume has more matter than any other volume, and any one atom is not attracted to any particular other atom. (Atoms are mostly neutral, non-ionized.) There is a tug one way that exactly balances all other tugs. It is just uniform, hot-but-cooling matter and radiation.

Eventually, in millions of years, fluffy clumps of atoms (not any solid mass, just regions of gas with slightly more density) start to form, and gravity lets these clumps gain mass. Any angular momentum keeps atoms in stable orbits around a center of mass, but subtle effects of momentum exchange happen (slingshot effect or gravity assist), combined with atomic cooling aided by low-energy atomic spin (rotational energy gets converted to weak photons which escape, see Krauss ATOM), to let the random rotational energy of atomic clouds escape, so that clouds can begin to condense.

This is the Dark Age, when there is no visible light because the universe has expanded and cooled below "red hot." There are no stars to give light.

At end of Dark Age, hydrogen molecules, neutral H₂, is able to cool the hot clumps or clouds of gas (by radiation) and let clouds collapse by gravity. But any ionization in a cloud where there is magnetism exerts a restraining force on collapse. Lawrence Krauss in ATOM p. 83-89. Pages 96-101: 30 solar masses in a cloud collapse slowly but in a 20-year span the infrared radiation becomes so great that half the mass is blown away. A great amount of gravitational potential energy radiates away. What remains keeps heating and becomes opaque to radiation; energy becomes trapped. Even so, radiation leaks away and is 10,000 times the brightness of our present Sun. Rising temperature results in ionization and hydrostatic equilibrium is established, with a diameter of 160 million miles. Contraction continues, but over 100 years. The cloud has become a star. Convection transports energy to the outside of the star, and it radiates at 100,000 times the brightness of the Sun for one year, but in the infrared, and with variable brightness. This is the T-Tauri star stage. Fusion power has not started yet! Eddington in 1926: "Try to picture the tumult! Disheveled atoms tear along at 50 miles a second with only a few tatters left of their elaborate cloaks of electrons torn from them is the scrimmage."

100,000,000 years old the first stars. They are metal-free. The biggest and hottest ones go supernova quickly and make the first elements heavier than beryllium.

400,000,000 years old the first galaxies, small ones.

Following is a NASA image, which I assume is not copyrighted. https://www.nasa.gov/sites/default/files/images/736107main_pia16876b_full.jpg

Modern Physics Theory of the Start

Time Line

Other books I have read