Thursday, April 11, 2024

More on our "Rare Earth"

I recently saw a social media post that said the recent total solar eclipse is proof of a "fine-tuned universe." That led to someone saying they did not believe in a fine-tuned universe, which led me to realize the phrase "fine-tuned universe" is a turn-off to atheists and agnostics, because it assumes a "tuner."

It is important to note who has used the phrase "fine-tuned":

"The laws of science, as we know them at present, contain many fundamental numbers, like the size of the electric charge of the electron and the ratio of the masses of the proton and the electron. ... The remarkable fact is that the values of these numbers seem to have been very finely adjusted to make possible the development of life." - Stephen Hawkins, "A Brief History of Time"

Hawkins was agnostic at best, and more likely would be described as an atheist, yet he used the phrase "finely adjusted." What has changed is atheists have become more thin-skinned and defensive in large part due to the rise of the defiant "New Atheists."

Regardless, it makes more sense to use the phrase "Rare Universe" instead of "Fine-Tuned Universe." Because our universe does appear to have characteristics that make its formation rare. Of course, the idea of a fine-tuned, or rare universe has to be attacked by those who see rarity as a threat. Personally, I believe there is no such thing as an atheist, there are only those who believe in different gods. Many atheist cosmologists believe in a god of probability, to which rarity is their antichrist. Hence, they torture math to find a way to reduce rarity, or try to prove alternative theories such as the multiverse.

The cosmological multiverse is not the multi-dimensional multiverse of science fiction or comic books, but the idea the Big Bang, during Cosmic Inflation, expanded at such a rate it threw quantum proto-energy and quantum proto-matter particles out far, far beyond our observable universe, where these "clumps" of quantum proto-matter and proto-energy coalesced into a near-infinite number of universes. These other universes may have formed different physical laws as they exited their quantum state into a physical state. Certainly many would either collapse into a supermassive black hole, others would dissipate into a cold mist. Given a trillion-quintillion different universes, of course probability would suggest at least one would form that could support two trillion galaxies, and as luck would have it, it was ours.

But the multiverse theory does not change the fact our universe is rare, instead it accepts it and attempts to prove it. That our universe is not rare is untenable.

Scientists had to hypothesize dark matter and dark energy to explain the balance in our universe, even though neither can be directly observed.

Our galaxy, the Milky Way Galaxy, is not rare. Barred spiral galaxies are the most numerous galaxies, representing about 40% of the galaxies in the universe. However, about 10% of spiral galaxies are "active galaxies", either Seyfert galaxies or quasars. Some cosmologists believe the radiation bursts from active galaxies would prevent life from forming within those galaxies. Subtracting the 10% of active galaxies brings the number of non-active barred spiral galaxies down to about 35%, or roughly one-third of the galaxies in the universe. But why focus on barred spiral galaxies? Barred spiral galaxies are considered the most mature galaxies. The maturity of a barred spiral galaxy means it has enough Population I stars which would have enough metal content to have rocky planets. Population I stars are third-generation stars. It is unlikely for life-bearing planetary systems to develop around second-generation Population II stars, and impossible around first-generation Population III stars. Also, barred spiral galaxies have fewer spiral arms, and more space between their spiral arms, which means they have a larger galactic habitable zone, but even more important, it means there are more areas in the galaxy that are not so crowded with stars that interstellar cosmic rays and nearby supernovas would disrupt life on nearby planetary systems. If barred spiral galaxies offer the best opportunity for life-bearing planetary systems, then only about one-third of the galaxies in the universe have a high potential for life.

Our Sun is rare. It is a G-Type star. Only about 7% of the Milky Way's stars are G-Type. G-Type stars have the largest circumstellar habitable zone, a habitable zone distant enough that tidal locking is not an issue, and a low level of x-rays compared to other small star types. The location of the Sun in the Milky Way is also rare. We are in the "suburbs" of the Milky Way, nestled between the Cygnus and Orion spurs, between the two major spiral arms of the Milky Way. We are in a place dense enough to benefit from past supernovas to generate planetary nebulas, but far enough away from the much denser main spiral arms to avoid destructive supernovas and more intense cosmic radiation.

Our Solar System is a rare. It was seeded not only with metals from a past supernova, but also very heavy metals from a past kilonova (the collision of two neutron stars, an exceedingly rare event). Smelting metal is required for intelligent life to advance beyond the stone age. The presence of metals like tin and copper in the Earth's crust allowed metallurgy to develop. The presence of uranium in the Earth's crust made the atomic age possible. Our solar system has a very large gas giant (Jupiter) as the first planet outside of the habitable zone, which reduces collisions from asteroids, comets, and meteors in the inner solar system.

Our planet is rare. It is in the center of the circumstellar habitable zone, has a magnetic field, and has oxygen at an ideal level. It has an axial tilt that provides seasons. The Earth has a large satellite (the Moon) that provides tides and reduces collisions with asteroids. The presence of every stable element in the Periodic Table in the surface of the Earth is unbelievably rare.

Cosmologist Brian Keating, while on the Joe Rogan Podcast in August of 2023, posited the idea if there were eight factors required for life on Earth (in reality there may be tens of trillions), and each factor had a one in a thousand chance of succeeding (but in reality it might be one in a billion), the result, one over ten to the twenty-fourth power, is comparable to one opportunity among every star that ever existed in the history of the universe. Not one star of those currently in the universe, but one star in the entire history of the universe. The universe is currently on its third generation of stars.

It really does not matter if one believes in a cosmic creator or not, to know scientifically, that our existence, and the existence of any intelligent life in our universe, is extremely rare and fortuitous. And it all starts with the fact the Big Bang did not dissipate into a cold mist, nor collapse back on itself.

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