Most of Strobel’s dinner table conversations center around education and the physical sciences. This is exciting for two empty nested her STEM teachers.
A few days before the high school students arrived on campus, my wife was wondering what to do when the science students didn’t receive their textbooks and Chromebooks until the fifth day of the semester.
She decided to practice on the periodic table of elements with pencil and paper. I proposed a connection between astronomy and “the cosmic connection with the elements”.
The periodic table is a graphical representation of the various types of atoms in the universe, such as hydrogen, helium, carbon, oxygen, iron, and uranium. Each type of atom, called an “element”, has unique chemical properties.
There are 92 naturally occurring elements in the universe, and dozens more synthesized in high energy laboratories.
Each atom has two basic parts. A central heavy nucleus made up of protons and neutrons and a cloud of low-mass electrons swirling around the nucleus. Since much of chemistry depends on the arrangement of outer electrons, the periodic table arranges elements in groups of similar outer electron configurations, increasing the total number of electrons from left to right and top to bottom.
The number of positively charged protons matches the number of negatively charged electrons in neutral atoms, so an increase in the number of protons in an element in the periodic table is accompanied by an increase in the number of electrons. Most chemistry ignores neutrons because they ride together and help hold the nucleus together.
Cosmic connections are made when we talk about where atoms came from in the first place. Chemists know that when carbon dioxide and water react with the energy of the sun to produce sugars and oxygen in a process called photosynthesis, or when burning coal or oil produces carbon dioxide. We often say that different materials are created from chemical reactions. .
Pretentious astronomers and nuclear physicists mock its “creation,” saying that chemical reactions “just shuffle atoms.” The number of different types of atoms (elements) in a chemical reaction remains the same, but the way in which the different elements connect or bond together in a chemical reaction changes. But where did the individual atoms themselves come from?
Many sciences have discovered that all the atoms of the Earth, planets, moons, etc., originate from cosmic processes and are mostly related to stars. Most of the hydrogen with one proton in the nucleus was created in the first microseconds after the universe began to expand (the big bang) when the universe was very hot and dense. Most of the helium in the universe was in the first minutes after the onset of expansion when some of the hydrogen was shattered together in a process called nuclear fusion, similar to what is happening now in the cores of stars like our sun. was created.
In hydrogen fusion, four hydrogen nuclei (four protons) collide to produce a helium nucleus with two protons and two neutrons. It turns out that the total mass of the helium nucleus is less than the combined mass of the original four protons. The mass lost in nuclear fusion was converted into energy – light! That’s what makes stars shine. The star is now slowly adding to the amount of helium in the universe.
Nuclear fusion requires very high temperatures and densities. As a star ages, it lacks hydrogen to fuse at its core, and the core fills with helium. The core is compressed and heated enough for the helium to fuse to produce heavier elements such as lithium, carbon, oxygen, silicon and iron. The more massive a star is, the more elements it can create, because ever-higher temperatures and densities are needed to create nuclei with more protons.
Explosive stellar events called supernovae can create many of the even heavier elements, such as nickel, copper, and zinc, from ultrafast nuclear fusion processes that last just a few minutes. It happens when a star dies and its core suddenly collapses, or when already dead low-mass stars, called white dwarfs in binary systems, siphon too much gas from their nearby companions. It turns out that the cores of massive dead stars, called neutron stars, also undergo temporary nuclear fusion when they collide with other neutron stars. Most of the gold and uranium in the universe comes from there.
Our theory of producing all different elements from nuclear fusion accurately predicts the observed abundances of all naturally occurring heavy elements found throughout the universe. Now we know why some elements such as carbon, oxygen, silicon and iron are common, while the heaviest elements such as gold, mercury and uranium are very rare.
To create Earth-like planets (and life on such planets), we need to create sufficient amounts of heavy elements in previous generations of stars and concentrate them in interstellar clouds to create significant quantities around forming stars. A lump should form. There is inevitably a “time difference” between the beginning of the universe and the beginning of life.
Dark Sky Festival is coming
Add the Dark Sky Festival in Sequoia and Kings National Parks to your calendar on September 24th.
There will be a presentation and a star party. The Khan Astronomical Society has many telescopes that people can use under pitch-black skies.
Contributing columnist Nick Strobel is director of the William M. Thomas Planetarium at Bakersfield College and author of the award-winning website AstronomyNotes.com.