The first and most basic element on the periodic table is hydrogen. A single atom of hydrogen consists of one positively charged proton in the center or nucleus, and one negatively charged electron orbiting it. This simple element was the first thing in the universe after the Big Bang, and there was a lot of it. Every one of these hydrogen atoms had an infinitely small amount of gravity, and each of those tiny atoms immediately began to pull on and towards one another. As more and more atoms found gravitational friends, they coalesced into large clouds of hydrogen. The more dense a cloud became, the larger its gravitational force, and subsequently it was able to pull in more hydrogen, and over and over the cycle repeated.
Now let’s compare this with a material we are all familiar with – water. If you dip your hand in a small bowl of water, you will feel its temperature and the unique, wet texture, but if you dive to the bottom of a deep pool or body of water, you will also feel the pressure of the water push in on your body. The larger the body of water, and the deeper one dives, the more pressure that will be exerted on the diver. The same process occurs with any element or compound, and these clouds of hydrogen were no exception. Clouds of hydrogen gas larger than our solar system pushed inward as they grew, and the individual atoms were packed tighter and tighter into the center, generating heat under the intense pressure. Somewhere around 25,000,000 degrees Fahrenheit, these hydrogen atoms ran out of space and began to merge, fusing four hydrogen nuclei into a heavier Helium atom, and releasing electrons, gamma rays, neutrinos, and heat and energy in the process. This process is known as nuclear fusion and is how stars are born.
The James Webb Space Telescope has been hard at work this past year, looking deep into nebulous clouds of gas around our galaxy that act as stellar nurseries. Comparing against the Hubble Space Telescopes famous images of the Carina Nebula, Tarantula Nebula, and the Eagle Nebula’s Pillars of Creation, we can see that the additional data available through observation in the near and mid-infrared allows astronomers to better understand this process of star formation and stellar nucleosynthesis.
Looking to our own star, we are constantly observing in many different wavelengths. With filters like Hydrogen Alpha that are readily available to backyard astronomers, we can begin to resolve the product of the fusion process taking place deep within the sun’s core, and using satellites and observatories we can trace the radiation, heat, and energy produced as it travels the 93 million miles to Earth, and beyond.
Understanding this process has been a key focus of physicists since 1920. After calculating that the mass of 4 hydrogen atoms was slightly more than that of one helium atom, British chemist Francis William Aston laid the groundwork of a science to understand how stars produce energy, and how we may be able to replicate it. On December 5th, 2022, scientists at the Lawerence Livermore National Laboratory in California successfully produced a fusion reaction in which the energy output was, for the first time, greater than the input, using lasers targeted at a gold canister containing deuterium and tritium. As we continue to develop technology, systems, and materials that can withstand such extreme temperatures and environments, we stand at the junction of a future right out of science fiction.
The Backyard Astronomer 