Star review: The Sun

Ask most people what they think about the sun, and they’ll likely be confused by your question.

They may respond in a meteorological context, thinking that you’re asking how they like the summer heat. Some may answer that the cloudless glare of a typical July day is just what they wanted for their beach vacation, that their tan will soon be a beautiful bronze. Others may be more confused than most, saying that The Son isn’t quite as great as The Father, but He’s certainly preferable to The Holy Ghost in your top three favorites of the Holy Trinity.

If you clarify the issue further to focus on the star at the center of our solar system, the average person may not have much of an opinion at all. The sun is just there, it’s always been a part of our lives, such a routine presence that we barely give it a second thought. It’s like asking if you’d rather have something other than a head at the top of your neck stalk, or if gravity ever gets on your nerves. You’ve never really considered if you’d prefer the sun to be a different color, closer to or further from the earth, shaped like a triangle rather than a circle, or made out of congealed meat rather than mostly hydrogen.

I asked my son (the one with an “o,” not a “u”) what he thought about the sun. Daniel responded “meh,” which the dictionary defines as “an expression of apathy, indifference, or boredom.” Even no less an authority than the Beatles were hard pressed to care one way or the other.

“Here comes the sun,” they sang on their landmark 1969 album Abbey Road. “It’s alright.”

I wanted to learn more about our closest star, that source and sustainer of all life on our planet. So I’m making the sun the subject of this week’s Friday Review.

Most weeks, I devote this space to a critique of websites. Occasionally, I’ve ventured farther afield, reviewing everything from the literary merit of the operating instructions for a box fan to movies (“Avatar was beamed through a projector”) to decades (absolutely loved The Aughts). I’ve even evaluated the worthiness of entire nations, for example giving England eight ampersands on a scale of one to ten, since the British isle is shaped like an ampersand and I very much enjoyed my 2005 visit there.

This being the height of a summer heat wave throughout much of the East Coast, and considering that we just had a solar eclipse across a narrow band of the Southern Hemisphere, and considering that two days from now is “Sunday,” let me tell you a little about our sun.

Obviously, when you’re talking sun, you’re bound to be talking about extremes. It has a diameter of almost a million miles, it weighs about 330,000 times what the earth weighs and, as you might expect, it’s very hot. While its surface temperature is a toasty 10,000° F, its core approaches 22 million degrees, rivaling even my hometown of Miami in August. Once regarded by astronomers as a relatively insignificant star, it recently got a status upgrade, being called brighter than about 85% of the stars in the Milky Way galaxy. (Take that, Luyten 726-8 AB!) By fusing hydrogen into helium, it releases tremendous amounts of energy, with estimates ranging as high as 384.6 yottawatts. That’s a lotta watts.

Though we tend to think of its location as being in “the sky,” it’s technically positioned close to the inner rim of the Milky Way’s Orion Arm, in what’s called the “Local Fluff” or “Gould Belt,” about 28,000 light years from the Galactic Center. Its neighborhood is known by cosmologists as the “Local Bubble,” a space of rarefied hot gas possibly produced as a remnant of the supernova Geminga. If you wanted to go there, you’d travel about 150 million kilometers (hang a hard right at Venus, you can’t miss it). Don’t rely on Yahoo maps to give you reliable directions. When I typed in “The Sun” as my destination, it sent me to Sun, Louisiana, and, even worse, had the nerve to route me through Atlanta.

The sun is a near-perfect sphere, with an oblateness of about 9 millionths, for those of you who care about oblateness. About three-quarters of its mass consists of hydrogen, with the rest being mostly helium. It exists in a plasmatic state rather than being a solid, so you couldn’t walk on its “surface” even if you had really thick soles on your shoes. Its color is white, although from the earth it may appear yellow because of atmospheric scattering.

And check this out: it’s rich in heavy elements, which could most plausibly have been produced by endergonic nuclear reactions during a supernova, or by transmutation through neutron absorption. Is that cool or what?

Looking beyond such dry technical specifications, let’s examine a little of the history of humans’ relationship with the sun. Most ancient cultures regarded it as a deity, as they did with most things they couldn’t understand (imagine what they’d think of Ke$ha or Rand Paul). Their most fundamental understanding of the sun was as a luminous disk in the sky, whose presence above the horizon created day and whose absence caused night. Many civilizations constructed monuments to the sun, from simple stone megaliths to more elaborate floorplans such as Stonehenge and the Aztec pyramids of Mexico.

One of the first people to offer a scientific explanation for the sun was the Greek philosopher Anaxagoras. He reasoned that it was a giant flaming ball of metal even bigger than a chariot. While today’s academia might’ve rewarded him with an endowed chair in the astrophysics department for such a revolutionary theory, he was instead imprisoned by the authorities and sentenced to death. A kind of tenure, you could argue, but probably not what he had in mind.

Later scientists refined these early ideas, usually at their own peril. Copernicus was the first to offer a mathematical model that put the sun rather than the earth at the center of the solar system. Galileo made the first known telescopic observations of sunspots. The Islamic astronomer Maghribi first estimated the sun’s size, and got it wrong only by half. For their troubles, all were teased mercilessly by their respective cultures.

Today, much of what we know about the sun comes from solar space missions, begun as early as 1959 with NASA’s Pioneer series of spacecrafts. Skylab and the Space Shuttle both delivered equipment into orbit that allowed for surveillance unfiltered by our atmosphere. Former President George W. Bush famously proposed a manned mission to the sun during a late-night party in 2006, when he suggested that the danger of such an attempt could be mitigated “if we go at night.” That plan was later scuttled by budget constraints and sobriety.

Earth-based observations have long been problematic, as looking at the sun with the naked eye for even brief periods can be painful. The refinement of light-concentrating optics like binoculars and telescopes seemed promising at first, though these came with the unfortunate side effect of making you blind. Kids still enjoy makeshift experiments out in the yard, proudly giving ants and other insects a close-up view of earth’s nearest star with a magnifying glass. This attempt to educate rarely turns out well for the bugs.

As for the future, earth’s fate in relationship to the sun is precarious. When it eventually enters its red giant phase (similar to adolescence in its trouble-making capacity), the sun will have a maximum radius beyond earth’s current orbit. This sounds bad but could be offset by the fact that the sun will have lost 30% of its mass due to stellar wind, and all the planets will have moved outward. “If it were only for this, earth would probably be spared,” notes Wikipedia hopefully. However, “new research suggests that earth will be swallowed by the sun owing to tidal interactions” and that, even if the earth could escape incineration in the sun, “still all its water will be boiled away and most of its atmosphere would escape into space.”

Despite these dire predictions, I think we can all agree that we’re much better off for the sun’s existence than we’d be floating in the icy void of interstellar space. Through photosynthesis, the energy of sunlight supports almost all life on this planet, with the only exceptions being creatures sustained by deep-sea volcanic vents, most toenail fungus and the aforementioned former president Bush. Because of these nutrients, because of the light and the warmth it provides, and because we all feel happier on a sunny day than we do on a cloudy one, we should do more to appreciate our local neighborhood furnace.

All hail, mighty Sol! I give thee one star on a scale of zero to one stars, because you’re the only star we need.

I hate to tell you this, but you just went blind

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