Look, up in the sky!

Throughout history, humans have been fascinated with the sky, and a lot of our myths were attempts to explain what goes on up there. In many cultures, the five planets visible to the naked eye (Mercury, Venus, Mars, Jupiter, and Saturn) were named after deities or attributes of the planets with surprising consistency.

Mercury was often named for its swiftness in orbiting the Sun; Venus was always associated with beauty because of its brightness; Mars’s red color led to it being named either for a violent deity or that color; Jupiter was always associated with the chief deity even though nobody in those times had any idea it was the largest planet; and Saturn, at least in the west, was named after Jupiter’s father.

This led to Uranus, which wasn’t discovered until the 18th century, being named after Saturn’s father, i.e. Jupiter’s grandfather. Neptune, discovered in the 19th century, and Pluto, discovered in the 20th century before being rightfully demoted from planetary status, were only named for Jupiter’s less cool brothers.

Since the planets were given attributes associated with deities, their relationship to each other must have meant something, and so the bogus art of astrology was invented, although it was obviously not complete prior to Uranus, Neptune, and Pluto being added, but then was clearly incorrect during the entire period of time that Pluto was a planet. (Hint: That was a joke. It was incorrect the entire time.)

Since humans are also hard-wired to see patterns, the stars above led to the definition of constellations, the night-time version of the “What is that cloud shaped like?” game.

It wasn’t really until the renaissance and the rise of science, including things like optics (one of Newton’s discoveries), which gave us telescopes, that we really started to take a look at the skies study them. But it is still astounding how so many laypeople know so little about what’s up there that we have had completely natural phenomena freaking us out since forever. Here are five examples of things in the sky that made people lose their stuff.

1. Total eclipse of the heart… er… Sun

Until science openly explained them, eclipses of any kind were scary. For one thing, nobody knew when they were coming until Royal Astronomer became a thing, but only the elite were privy to the information, so the Sun would go out or the Moon would turn blood red, or either one of them would appear to lose a piece at random and without warning. Generally, the belief was that the Moon or Sun (particularly the latter) was being consumed by some malevolent yet invisible beast that needed to be scared away.

But long after modern science explained that an eclipse was nothing more than the Moon passing in front of the Sun or the Earth passing in front of the Moon, shit went down in 1878, at least in low-information areas.

The thing about this eclipse was that it had been predicted close to a century before, had been well-publicized, and was going to put the path of totality across the entire U.S. for the first time since its founding. There’s even a book about it, American Eclipse. But there’s also a tragic part of the story. While the news had spread across most of the growing nation, it didn’t make it to Texas, and farm workers there, confronted with the sudden loss of the Sun, took it to mean all kinds of things. A lot of them thought that it was a portent of the return of Jesus, and in at least one case, a father killed his children and then himself in order to avoid the apocalypse.

2. Captain Comet!

Ah, comets. They are an incredibly rare sight in the sky and well worth traveling to see if that’s what you need to do. I remember a long trek into the darkness when I was pretty young to go see Comet Hyakutake, and yes it was worth it. It was a glorious blue-green fuzzball planted in space with a huge tail. Of course, I knew what it was. In the past, not so much.

In the ancient world, yet again, they were seen as bad omens because something in the heavens had gone wrong. The heavens, you see, were supposed to be perfect, but there was suddenly this weird… blot on them. Was it a star that grew fuzzy? Was it coming to eat the Earth? What could be done?

That may all sound silly, but as recently as 1910, people still flipped their shit over the return of one of the more predictable and periodic of “fuzzy stars.” That would be Comet Halley. And, by the way, it’s not pronounced “Hay-lee.” It’s “Hall-lee.”

And why did it happen? Simple. A French astronomer who should have known better, wrote that the tail of the comet was full of gases, including hydrogen and cyanide, and if the Earth passed through the tail, we would either be gassed to death or blown up. Unfortunately, another French astronomer at the time actually played “Got your back” with him, and that was all it took.

It was pseudoscience bullshit at its finest, propagated by the unquestioning and uninformed (when it comes to science) media, and it created a panic even though it was completely wrong.

The worst part about Halley’s 1910 appearance? It bore out Mark Twain’s statement, paraphrased probably: “I came into the world with it, I will go out with it.” And he did. Goddamit.

3. Meteoric rise is an oxymoron

And it definitely is, because a meteor only becomes one because it’s falling. And while we’re here, let’s look at three often confused words: Meteor, meteoroid, and meteorite.

The order is this: Before it gets here and is still out in space, it’s a meteoroid. Once it hits our atmosphere and starts to glow and burn up, it has become a meteor. Only the bits that actually survive to slam into the planet get to be called meteorites. Oid, or, ite. I suppose you could think of it as being in the vOID, coming fOR you, and then crash, goodnITE.

So the things that mostly cause panic are meteors, and quite recently, a meteor blowing up over Russia convinced people that they were under attack. It was a fireball that crashed into the atmosphere on February 15, 2013, and it actually did cause damage and injuries on the ground.

The numbers on the Chelyabinsk meteor are truly staggering, especially to think that they involved no high explosives, just friction and pure physics (Hello again, Sir Isaac!) The thing was about 66 feet in diameter, which is the length of a cricket pitch, or about four feet longer than a bowling lane. It compares to a lot of things, and you can find some fun examples here.

But there was nothing fun about this asteroid. It came screaming through our atmosphere at about 41,000 miles an hour at a steep angle. The heat from the friction of our atmosphere quickly turned it into a fireball of the superbolide variety, which is one that is brighter than the sun. It exploded about 18 miles up. That explosion created a fireball of hot gas and dust a little over four miles in diameter. The kinetic energy of the event was about 30 times the force of the atom bomb dropped on Hiroshima.

Over 7,200 buildings were damaged and 1,500 people were injured enough to need medical attention, mostly due to flying glass and other effects of the shockwave. Unlike other items on this list, these events actually can be dangerous, although this was the first time in recorded history that people were known to have been injured by a meteor. The Tunguska event, in 1908, was a little bit bigger and also in Russia, but happened in a remote and sparsely populated area, with no reported human injuries. Local reindeer were not so lucky.

4. Conjunction junction, what’s your function?

A conjunction is defined as any two or more objects in space which appear to be close together or overlapping when viewed from the Earth. Every solar eclipse is a conjunction of the Sun and Moon as seen from the Earth. Oddly enough, a lunar eclipse is not a conjunction from our point of view, because it’s our planet that’s casting the shadow on the Moon.

Conjunctions shouldn’t be all that surprising for a few reasons.

First is that most of the planets pretty much orbit in the same plane, defined by the plane in which the Earth orbits because that makes the most sense from an observational standpoint.

The inclination of Earth’s orbit is zero degrees by definition and the plane we orbit in is called the ecliptic. You can probably figure out where that name came from. Out of the planets, the one with the greatest inclination is Mercury, at 7º. Counting objects in the solar system in general, the dwarf planet Pluto has an inclination of 17.2º — which is just another argument against it being a true planet. None of the planets not yet mentioned have an inclination of more than 4º, which really isn’t a whole lot.

The second reason conjunctions should not be all that surprising is because each planet has to move at a particular velocity relative to its distance from the Sun to maintain its orbit. The farther out you are, the faster you have to go. Although this is a function of gravity, the airplane analogy will show you why this makes sense.

As an airplane gains speed, the velocity of air over the wings increases, generating more lift, bringing the airplane higher. In space, there’s no air to deal with, but remember that any object in orbit is essentially falling around the body it orbits, but doing it fast enough to keep missing.

If it slows down too much, it will start to fall, but if it speeds up its orbit will get bigger. This is directly analogous to ballistics, which describes the arc of a flying projectile. The faster it launches the farther it goes and the bigger the arc it makes. An arc in orbit becomes an ellipse.

Since every planet is moving at the speed required to keep it at the distance it is, things are likely to sync up occasionally. Sometimes, it will only be one or two planets, but on certain instances, it will be most or all of them. This video is a perfect example. Each one of the balls is on a string of a different length, so its natural period is different. Sometimes, the pattern becomes quite chaotic, but every so often it syncs up perfectly. Note that all of them did start in sync, so it is mathematically inevitable that they will sync up again at the point that all of the different period multiply to the same number. Our solar system is no different since the planets all started as rings of gas and dust swirling around the Sun. There was a sync point somewhen.

So conjunctions are a completely normal phenomenon, but that doesn’t mean that people haven’t gone completely stupid with them. The first way is via astrology, which isn’t even worth debunking because it’s such a load. The Sun is 99.8% of the mass of the solar system, so it constantly has more influence in every possible way over everything else hands down. What influence did the planets have upon your personality at birth? Less than zero. The only relevant factor, really, is that people’s personalities are formed by their relative age when they started school, so that is influenced by the season they were born in, but that’s about it.

As for the modern version of people going completely stupid over conjunctions, it happened in the early 1980s, after the 1974 publication of the book The Jupiter Effect by John Gribbin and Stephen Plagemann. In short, they predicted that a conjunction of the planets on March 10, 1982 would cause a series of earthquakes that would wipe out Los Angeles.

Since you’re reading this in at least the year 2020 and I’m quite safely in Los Angeles, you know how their prediction turned out. This didn’t stop them from backtracking a month later and releasing a follow-up book called The Jupiter Effect Reconsidered (aka We Want More Money from the Gullible) in which they claimed, “Oh… we miscalculated. The date was actually in 1980, and the conjunction (that hadn’t happened yet) caused Mount St. Helens to erupt.”

Still, just like with the whole end of the world 2012 predictions, at least some people bought into it.

5. The original star wars

The last item on our list is possibly a one-off, occurring on April 14, 1561 in Nuremberg, Germany. Whether it actually even happened is debatable since only a single account of it survives in the form of a broadsheet — basically the blog post of its day. If it had been as widespread as the story makes it seem, after all, there should have been reports from all across Europe unless, of course, the point of view from Nuremberg created the exceptional event in the first place.

It was described as an aerial battle that began between 4 and 5 a.m. when “a dreadful apparition occurred on the sun.” I’ll quote the rest of the paragraph in translation in full from the article linked above: “At first there appeared in the middle of the sun two blood-red semicircular arcs, just like the moon in its last quarter. And in the sun, above and below and on both sides, the color was blood, there stood a round ball of partly dull, partly black ferrous color. Likewise there stood on both sides and as a torus about the sun such blood-red ones and other balls in large numbers, about three in a line and four in a square, also some alone.”

The unknown author goes on to describe the objects — spheres, rods, and crosses — as battling with each other for about an hour, swirling back and forth. Eventually, the objects seemed to become fatigued and fell to the Earth, where they “wasted away… with immense smoke.

Now, what could have caused this phenomenon? The obvious answers are that it was a slow news day or that it was religious propaganda or some other wind-up. But if it were an actual phenomenon and really only remarked on in one village, then it’s quite possible that it was a meteor shower with an apparent radiant, or source, that happened to line up with the Sun.

It was a Monday, with a new Moon. The Sun rose in the east at 5:05 a.m., so the invisible Moon was somewhere around that part of the sky, too. But this also immediately calls the story into question, since the phenomenon seen coming from the Sun happened before sunrise according to the account. But if we consider that to just be human error, what we have is the Pearl Harbor effect. The attackers come in with the rising Sun behind them, making them hard to see or understand.

On top of that, if they’re coming in from that direction, they’re coming in at a very shallow angle. See the notes on the Russian meteor above. This can lead to some super-heated objects, which would glow red as reported, and anything not red hot against the Sun would appear black. If it happened to be a swarm of objects, like a bunch of small rocks and dust or a bigger piece that broke up, all flying in at once, the chaotic motion could certainly make it seem like a battle.

There is a meteor shower that happens around that time of year called the Lyrids, which is very short-lived, although I haven’t yet been able to find out whether its radiant was near the Sun in 1561. But a particularly heavy shower coming in at just the right angle could have an unusual effect in a limited area.

Or… the author just pulled it out of his ass for his own reasons. We can never know.


Photo credit: Staff Sgt. Christopher Ruano, F.E. Warren Air Force Base.

Betelgeuse, Betelgeuse, Betelgeuse

There’s been a lot of talk in the news lately about the star Betelgeuse, and whether it’s about to explode and go nova. The main reason this discussion is happening is because the star suddenly got very dim very quickly, and dimmer than we have ever observed it to be. The dimming itself isn’t unusual because Betelgeuse is a variable star, meaning that its apparent brightness changes. What’s unusual now is the magnitude of that change. In only two months, Betelgeuse dropped from 10th brightest star in the northern night sky to 21st.

Stars and the physics in them have always fascinated me because they are a perfect example of macro and micro coming together — the very large displaying the power of the very tiny at work.

Fusion without confusion

What is a star? Simply put, it’s a big ball of gas that is so massive that its own gravity makes it ignite in nuclear fusion, creating heat and light. As far as we know, the very first stars started out as cloud of the lightest, simplest element, hydrogen, which in its basic form is one proton with one electron bound to it. I say “bound to” rather than “orbiting” because that old model of discrete little electrons circling the nucleus like planets orbit the Sun is just wrong. It’s better to think of the electron or electrons as existing as a potential force spread out over a certain area statistically, with the shapes and volumes of those areas varying with the energy of the electron. It’s not in one place at any given time, but it’s likely to be in certain places and not in others, and this goes for every electron in the atom.

Yes, welcome to the weirdness of quantum physics. The layman’s takeaway here is that the electrons create what you can think of as a force field far “above” the nucleus that keeps other nuclei from getting too close. They’re like the walls of houses that keep the nosy neighbors from wandering in.

And that works just fine on most scales. The electrons are doing all of the work so that the atoms in your cells don’t fuse together and it even works right up to the level you can perceive. When you touch a table, for example, you aren’t really touching it. Rather, the electrons in your finger are bumping against the electrons in the table and are acting as mutual bouncers keeping each other out so that your hand and the table don’t merge.

Oh, sure, you will exchange some electrons with whatever you touch because they can just be finicky like that. But, for the most part, this is an impenetrable barrier that keeps things well-defined.

It doesn’t break down until enormous forces come into play. In the case of stars, that force is called gravity, and it’s not until that ball of hydrogen reaches a certain density that things begin to happen. Mainly, the force of gravity working on it becomes enough to overcome the force of the electrons maintaining boundaries. All of a sudden, those neat electron orbital shells go wonky, and the protons start to get to know each other. Now, normally, they would repel because they have the same charge, but their charges are so much weaker that by this point it doesn’t matter. Protons start to get forced together, and then the magic happens.

It’s elementary

I won’t get too heavy into the physics here — you can learn more if you’d like — but the key point is that this gravitational mushing turns hydrogen into helium, the next heaviest element, which has two protons, two neutrons, and two electrons, and in the process a lot of energy (relatively speaking) gets released.

This continues on for a long time until the hydrogen has almost but not quite run out, at which point the star starts to smoosh all of that helium into carbon, and the process cascades from there. Combining each new element with more helium runs down the chain to create oxygen, neon, magnesium, silicon, sulfur, argon, calcium, titanium, chromium, and then iron.

A star is basically a forge that creates the heavier elements that become the building blocks of planets, all subsequent new stars (which don’t start as pure hydrogen), and, eventually, life.

There’s one critical element to mention, though: while the force of gravity has been enough to make the fusion happen, at the same time the opposing force of the energy released by that fusion has been enough to push back and create a sort of equilibrium so that the star doesn’t collapse or expand. It pretty much maintains its size.

And then iron synthesis comes along, and it’s a game changer. Why? Because, unlike those other fusion reactions, this one doesn’t produce sufficient energy to fight gravity any longer. Boom, it’s like a light switch is turned off. All of a sudden, the floorboards give out, and all of that mass up above the ceiling is free to come crashing down into the basement, and that doesn’t go well when it hits bottom. Above a certain original mass, you get a black hole. Below it, you get an enormous explosion which scatters all of those elements outward and releases an incredible amount of energy.

It would be a super nova

If that happened to Betelgeuse during 14th or 15th centuries, we’d see it here soon, since the star is only about six hundred light years away. For a while, it would be brighter than the full Moon at night, and visible during the day. And it couldn’t happen to a nicer star. It’s one that you’ve probably seen since its constellation is so memorable.

Betelgeuse is the right shoulder of Orion, assuming that he’s facing us, and is visibly red from down here. In official terms, the star is known as Alpha Orionis, meaning the first, or brightest, star in the constellation Orion. The interesting part about this designation is that it’s only sometimes the brightest, again because of the variable thing. Rigel is often brighter, but when Sir John Herschel made his observations and his catalog, Betelgeuse was brighter, so it got the A rating.

If you’re wondering about the name of the star, it’s got nothing to do with the Tim Burton film. Rather, it comes from the Arabic name for it, إبط الجوزاء (‘iibt aljawaza’). If you pronounce it fast enough a few times, it kind of starts to sound like “Betelgeuse.”

Just don’t say it three times. Or, maybe, do — because seeing a supernova of this magnitude at this point in our history wouldn’t only be great for humanity in general, it would be a boon to many different sciences. The last visible supernova happened in 1987, but it was only visible from the Southern Hemisphere, and it was about 160,000 light years away, or just over 49,000 parsecs.

This one would be visible by everyone in the Northern Hemisphere, day and night, for a good period of time, and it would serve to make people aware of the universe out there, and maybe even ask questions and listen to scientists. It might even get them to realize that the ultimate survival route for the entire human race — and a lot of other species on this planet — is to get off of this planet and start colonizing, except to do it in a low-impact and benevolent way, rather than the slash-and-burn methods used by our ancestors who raped and pillaged their way out of Europe and into the “new” world. (Funny how none of it was new to the people who had been living there already.)

Anyway… here’s to hoping that one of the most violent events in the universe can grace our night and day skies soon, and pull us out of ourselves. Maybe we do need a cataclysmic event to unite the planet — but that doesn’t mean that the cataclysm needs to be anywhere near us. Just that we need to be aware of it.

What better screen than the sky above?

If you say the name three times, it appears. Betelgeuse.

Betelgeuse.

Betelgeuse!

Christmas Countdown, Sunday #2

Day 10

Sunday’s theme is a reminder that there are more holidays than just Christmas in December — or in the winter in general, so we’ll be going to another continent for this one. Now, why are there so many holidays this time of year?

Simple. Astrophysics.

The very basic version of this is that the Earth rotates around its axis, which you can imagine as a stick that goes from its north to south pole. (Illustrated version available here.) The Earth is perfectly happy to rotate around this axis at a rate that gives us one revolution per day. While the Earth rotates around its axis, it also orbits the Sun, and this takes about 365.25 days (which is why Leap Years exist, but that’s not relevant here.)

Now if the axis were straight up and down — meaning that the equator was exactly level with the Earth’s orbit, we’d have no seasons and all days would be the same length. However, it’s not. It’s tilted about 23 degrees. This means that as the Earth goes around the Sun, the angle at which light hits it changes. On the first day of spring and first day of fall (in the Northern hemisphere), the axis is straight up and down relative to the orbit, so day and night are of equal length. As spring progresses into summer, the axis (in the north) tilts toward the Sun; from fall into winter, it tilts away. Tilting toward makes days longer; tilting away makes them shorter.

In winter, the days become the shortest of all, and the winter holidays, like Christmas, tend to happen right around that longest night of the year, which is the Winter Solstice, generally around December 22nd now, but a few thousand years ago it was closer to the 25th.

But the salient bit is this: Once the solstice comes and goes, the days after that start to get longer, light returns, and the world is eventually reborn in spring. All of these winter festivals are partly a way for communities to come together at the darkest and coldest parts of the year, and partly a way to remind them that it’s going to get better soon.

Which brings us to Diwali, which actually happened right around Thanksgiving (in America) this year, although it’s a holiday celebrated by Hindus, Sikhs, Jains and some Buddhists around the world. Basically, it celebrates the triumph of good over evil, and prominently features, well… lights, since it’s the festival of lights. But it definitely fits the winter theme, and again you can see how astronomical realities can dictate social conventions. When the year gets dark, we celebrate the fact that the light will always win and return.

 

Don’t forget to check out the previous post or watch the next.