Cosmologic philosophy: fine tuning of stars and the protons (Introduction)

by David Turell , Saturday, December 10, 2022, 19:37 (714 days ago) @ David Turell

One precise wavelength is magical:

https://bigthink.com/starts-with-a-bang/21cm-magic-length/?utm_source=mailchimp&utm...

"In all the Universe, the most common atom of all is hydrogen, with just one proton and one electron. Wherever new stars form, hydrogen atoms become ionized, becoming neutral again if those free electrons can find their way back to a free proton. Although the electrons will typically cascade down the allowed energy levels into the ground state, that normally produces only a specific set of infrared, visible, and ultraviolet light. But more importantly, a special transition occurs in hydrogen that produces light of about the size of your hand: 21 centimeters (about 8¼”) in wavelength. That’s a magic length, and it just might someday unlock the darkest secrets hiding out in the recesses of the Universe.

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"The most famous of these transitions occurs in the simplest type of atom of all: hydrogen. With just one proton and one electron, every time you form a neutral hydrogen atom and the electron cascades down to the ground (lowest-energy) state, there’s a 50% chance that the spins of the central proton and the electron will be aligned, with a 50% chance that the spins will be anti-aligned.

"If the spins are anti-aligned, that’s truly the lowest-energy state; there’s nowhere to go via transition that will result in the emission of energy at all. But if the spins are aligned, it becomes possible to quantum tunnel to the anti-aligned state: even though the direct transition process is forbidden, tunneling allows you to go straight from the starting point to the ending point, emitting a photon in the process.

"This transition, because of its “forbidden” nature, takes an extremely long time to occur: approximately 10 million years for the average atom. However, this long lifetime of the slightly excited, aligned case for a hydrogen atom has an upside to it: the photon that gets emitted, at 21 centimeters in wavelength and with a frequency of 1420 megahertz, is intrinsically, extremely narrow. In fact, it’s the narrowest, most precise transition line known in all of atomic and nuclear physics!

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"Although it’s never yet been done, this gives us a tremendously provocative way to measure the early Universe: by finding a cloud of hydrogen-rich gas, even one that’s never formed stars, we could look for this spin-flip signal — accounting for the expansion of the Universe and the corresponding redshift of the light — to measure the atoms in the Universe from the earliest times ever seen. The only “broadening” to the line we’d expect to see would come from thermal and kinetic effects: from the non-zero temperature and the gravitationally-induced motion of the atoms that emit those 21 centimeter signals.

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"Again, that same radiation — of 21 centimeters in wavelength — gets produced, and every time we measure that 21 centimeter wavelength localized in a specific region of space, even if it gets redshifted by the expansion of the Universe, what we’re seeing is evidence of recent star-formation. Wherever star-formation occurs, hydrogen gets ionized, and whenever those atoms become neutral and de-excite again, this specific-wavelength radiation persists for tens of millions of years.

"If we had the capability of sensitively mapping this 21 centimeter emission in all directions and at all redshifts (i.e., distances) in space, we could literally uncover the star-formation history of the entire Universe, as well as the de-excitation of the hydrogen atoms first formed in the aftermath of the hot Big Bang.

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"In all the Universe, there are only a few known quantum transitions with the precision inherent to the hyperfine spin-flip transition of hydrogen, resulting in the emission of radiation that’s 21 centimeters in wavelength. If we want to identify ongoing and recent star-formation across the Universe, the first atomic signals even before the first stars were formed, or the relic strength of yet-undetected gravitational waves left over from cosmic inflation, it becomes clear that the 21 centimeter transition is the most important probe we have in all the cosmos. In many ways, it’s the “magic length” for uncovering some of nature’s greatest secrets. (my bold)

Comment: This precise event in star formation is what has created all the structures in the universe. Fine tuning is simply evidence of a designer