A lot of years ago, way back in 1968, I was a big Star Trek fan. You know, Star Trek, the original series (known as TOS these days). Spock, with the pointed ears. James T. Kirk. Dr. McCoy. The Starship Enterprise and a five-year mission to seek out new life and new civilizations, to boldly go where no man has gone before…
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| Spock, Kirk, McCoy s |
I have some vivid memories of those television shows. One in particular, “Bread and Circuses,” dealt with a civilization similar to that of Imperial Rome, including the bloody gladiatorial contests.
In that particular episode, the Enterprise landing team of Kirk, Spock, and Dr. McCoy are captured by the government and forced into the arena to kill or be killed. They survive and ultimately escape due to the help of a peaceful rebel group characterized as sun worshipers.
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| Escape! S |
At the end of the episode, when everyone is back on Enterprise, safe and sound, Spock wonders about the sun worshipers, who called themselves “Children of the Sun.”
“How could sun-worshiping Romans adhere to a philosophy of peace?” he asks. “Sun worship is a primitive and superstitious religion, anything but peaceful.”
Enterprise’s Communications Officer, Lieutenant Uhura, sets him straight.
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| “It’s not the sun up in the sky,” she says, “it’s the Son of God.” S
An interesting and thought provoking denouement, don’t you think? Who knew the 1960’s had such depth? Maybe it wasn’t all about drugs and Vietnam.
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Worship
Worship is an interesting word in this context. it’s used here as a verb, “showing reverence and adoration for a deity; honoring with religious rites.”
In the Star Trek episode the concept of religion is a foil used to juxtapose the notion of civilized religion with savagery of paganism. “Bread and Circuses” is a neat little vehicle for the task.
But as we all know well enough these days, civilized religions aren’t always peaceful. The “new” religions of social justice and environmentalism are incredibly vicious.
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| Social Justice worship service S |
Could it be that paganism isn't always savage?
Religion vs Nature
Now that I’ve set the stage to discuss religion, peace, and savagery, I’m going to completely abandon the theme. I introduced it only because my mind went to that particular Star Trek episode the other morning when I paused for a moment to enjoy the warmth of the late-February sun.
Overnight the mercury had tumbled all the way down to minus 4 or so, and after a month of warmish weather the cold was a bit of a shock. But the sun was shining higher in the sky than it had been since late October. It was shining more directly down, its warming rays (or warming photons) not having to travel through as much atmosphere to reach the surface. The sunlight was therefore more concentrated, or at least less diluted (or diffuse), and therefore, more warming.
Which was really nice, and felt really, really good.
Standing out on the chill winter prairie, where nature is so clearly in charge and mankind’s imagined powers so clearly an illusion, the warm kiss of sunlight is more than enough to illustrate why various people, down through the ages, came to worship the sun.
Thank the sun
Worship is the wrong word. Appreciate is probably a better word. Leave religion aside for now, and think about our very existence. It all starts with the sun.
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| Sol. S |
In order to exist, at least in terms of our natural, corporeal existence, we need a place to exist, a place to be, a place to live our lives. Our place is on the planet Earth, which orbits the sun at a distance of 93 million miles. That distance turns out to be in the “Goldilocks Zone,” at least in this solar system, a location which is “just right” for liquid water and life as we know it to exist. But before we get ahead of ourselves, our planet would never have formed or had anything to orbit were it not for the sun.
The sun is the gravitational center of our solar system. But those 10 words don’t really do justice to the magnitude of the sun’s mass.
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| The sun and planets. Scale is correct for size but not for distance. S |
Think of it this way. The Earth is huge. Just look outside. It’s everywhere. Mountains and oceans and everything. It’s so huge that you can barely see mankind’s biggest structures from low earth orbit, a paltry 99 miles above the surface, about the distance of a single round trip between the EJE Ranch and the Panhandle Research and Extension Center at Scottsbluff.
Earth is so huge that it’s more than 7,300 miles in diameter and weighs (masses is actually the correct term) 5.97219 times ten-to-the-twenty-fourth kilograms, or 13.2 septillion pounds. For those of you keeping score at home, that’s 13,200,000,000,000,000,000,000,000 pounds.
Now that’s huge, but Earth is is only the fifth largest planet in our solar system. Jupiter, the largest planet, masses nearly 320 times as much as Earth. But guess what? Jupiter is a pipsqueak compared to the sun. The sun is well over 1,000 times more massive than Jupiter. In fact, the sun makes up 99.86 percent of the total mass of the solar system. In many ways it’s fair to say the sun is the solar system. All the planets, comets, asteroids, dust and gasses, people, skyscrapers, aircraft carriers and deflated footballs -- these are no more than a bit of fluff floating about the sun.
The mass of the sun exerts gravity, as described by Newton, and it’s that gravity which holds the solar system together and allows the planets, including our own Earth, to whirl endlessly in orbit.
Gravity
So it’s the gravity of the sun, then, that gives us a place to be. Think of how powerful that force must be! Not only does it keep the planets in place (in the case of Pluto, the farthest, a distance of 3.6 trillion miles), the sun’s gravity controls everything in the solar system, out to the incomprehensible distance of 3,627,000,000,000 miles, more than 40 times the distance between Earth and the sun, and it continues to exert a powerful gravitational influence hundreds -- perhaps as much as a thousand -- times farther than that.
Gravity is certainly a powerful force, strong enough to hold the solar system together over vast distances. But gravity is actually the weakest of the four elemental forces of nature, far weaker than the strong and weak nuclear forces and the electromagnetic force.
Gravity is so weak, in fact, that by muscle power alone you and I overcome the Earth’s gravity all the time. When you reach up to scratch your nose, you are overpowering the Earth!
But even though gravity is the weakest of the elemental forces, it’s still very powerful.
According to Newton’s law of universal gravitation, which is plenty good enough for a discussion at this level, gravity is a force exerted by matter.
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| Sir Isaac Newton, 1642-1727. S |
Matter, for this purpose, is every bit of physical stuff which has mass. Every discrete piece of matter exerts a gravitational force on every other bit of matter. The gravitational force between bits of matter is directly proportional to the sum of their masses and inversely proportional to the square of the distance separating them. In other words, the larger the mass, the more gravity, and the closer the proximity of the masses, the stronger the force. Whew!
The sun’s gravity doesn’t just hold the solar system together, it holds the sun together. In doing so, the sun’s gravity makes life as we know it possible.
Hydrogen
Remember that the sun is 1,050 times more massive than Jupiter, which is 320 times more massive than Earth. For the scorekeepers at home, that makes the sun 336,000 times more massive than Earth.
Now Earth is a terrestrial or rocky planet with an iron core. Rocks and iron are heavy! In Earth’s case, as we noted before, 13.2 septillion pounds of heavy. That’s a 132 followed by 23 zeroes.
The sun, however, is made up of the lightest elements in the universe, hydrogen and helium. It’s about 75 percent hydrogen and 25 percent helium, with a light dusting of heavier elements. Let’s ignore the helium for the moment, because it’s actually a byproduct. When the solar system first formed, about 4.6 billion years ago, the sun was almost entirely made up of hydrogen. Then, as now, there was such a large mass of hydrogen in the sun that its gravity became an unimaginably huge force -- proportional to the mass and inversely proportional to the square of the distance of separation.
Lets think about hydrogen for a moment. It’s the lightest element, and as most of us recall from fourth grade science, it’s made up of a single, positively charged proton and a single, negatively charged electron.
Like all atoms, hydrogen atoms are tiny. They’re even tinier than tiny. If you think of a hydrogen atom as a mini solar system, with the proton in the center playing the sun and the electron taking the part of an orbiting planet, and if the proton were expanded 25 trillion (25,000,000,000,000) times to one inch in diameter, the electron’s orbit would be clear out at 1,400 feet from the proton! If you expanded the proton to the size of the sun, the electron would orbit four times farther out than Pluto.
So it’s pretty clear that atoms are mostly empty space, but that emptiness is charged with powerful nuclear and electromagnetic forces that hold the atom together and at the same time keep the electrons orbiting at such great distances. Those forces also give matter its solidity. Matter is made up of atoms, and atoms are mostly empty space. When we feel the structure of a rock or a steel beam or a sheet of paper, we’re actually feeling the interaction of the electromagnetic forces of the atoms in our finger with the atoms in the object we touch.
So. Back to the sun, hydrogen, and gravity. Gravity pulls (and continues to pull) all of those hydrogen atoms tighter and tighter and tighter until something wonderful happens. At the core of the sun, where gravity has driven temperatures and pressures to astronomical heights, the hydrogen atoms are bashed together with such force that they fuse -- and become something different.
Warmth
Lets backtrack a bit and remember that part of what prompted this essay was the feel of the sun’s warmth on my face on a frigid February morning, and that the warmth I felt was transmitted across 93 million miles of empty space.
As hydrogen atoms smash together in the core of the sun they fuse into helium atoms. The mass of a helium atom is just slightly less than the mass of the two fusing hydrogen atoms. The missing mass doesn’t just disappear, it becomes energy as described by Einstein in his famous equation E=mc2. The energy released by that tiny bit of leftover matter is enormous.
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| Isotopes of hydrogen fusing into helium and releasing energy. S |
To put it in perspective, the fusion of one gram (0.035 ounces) of hydrogen yields 85 billion British Thermal Units (BTU’s) of energy. That’s 33 million horsepower-hours or 25 million kilowatt-hours. But those are just numbers. Twenty-four grams of fusing hydrogen -- less than an ounce -- could power the entire U.S. electrical grid for a full year.
As hydrogen atoms fuse into helium in the core of the sun, the energy is released as photons, discrete packets of electromagnetic energy. We can think of them as light particles (we can also think of them as light waves, but wave-particle duality is an essay for another day), and as light particles they travel at the speed of light, 300,000 kilometers (186,000 miles) per second.
Remember, though, that this fusion occurs in the core of the sun, which is packed full of compressed hydrogen at extremely high densities. The energetic photons have to fight their way out of the core in order to leave the sun as a ray of light. That journey, from the core to the surface of the sun, made at the speed of light, takes a full century to complete as the photons bounce nearly endlessly off of the densely packed hydrogen and helium atoms.
Once free of the core the photons speed out into space in all directions. They’ve lost none of their energy in 100 years of ricocheting about in the core. As they fly out from the sun, a small percentage are aimed directly at the Earth, where they land after about nine minutes of travel.
The solar flux (quantity of solar energy) striking the earth is a constant 175 petawats, about 10-to-the-15th watts. About thirty percent of that is reflected by the atmosphere, but the rest of it reaches the surface.
And once it reaches the surface, it provides every bit of energy required for life. It energizes the photosynthetic process in plants, which take carbon dioxide and hydrogen and solar energy and make starch and cellulose and oxygen. Animals eat the starch and cellulose and breathe the oxygen. Other animals eat the plant eating animals. The important point is that every scrap of energy it takes to make a plant or to make an animal comes from the sun.
And that’s probably enough for today. Whether we think about it or not, whether we appreciate it or not, the sun is the bringer of life as we know it.
And the bonus is the feel of warm sunshine on a frosty February morn.
