Wednesday Wonders: Now, Voyager

+Wednesday’s theme will be science, a subject that excites me as much as history on Monday and language on Tuesday. Here’s the first installment of Wednesday Wonders — all about science.

Now, Voyager

Last week, NASA managed something pretty incredible. They managed to bring the Voyager 2 probe back online after a system glitch forced it to shut down. Basically, the craft was supposed to do a 360° roll in order to test its magnetometer.

When the maneuver didn’t happen (or right before it was going to), two separate, energy-intensive systems wound up running at the same time and the probe went into emergency shut-down to conserve energy, turning off all of its scientific instruments, in effect causing data transmission back to home to go silent.

The twin Voyager probes are already amazing enough. They were launched in 1977, with Voyager 2 actually lifting off sixteen days earlier. The reason for the backwards order at the start of the mission is that Voyager 1 was actually going to “get there first” as it were.

It was an ambitious project, taking advantage of planetary placement to use various gravitational slingshot maneuvers to allow the probes to visit all of the outer planets — Jupiter and Saturn for both probes, and Uranus and Neptune as well for Voyager 2.

Not included: Pluto, which was still considered a planet at the time. It was in a totally different part of the solar system. Also, by the time the probes got there in 1989, Pluto’s eccentric orbit had actually brought it closer to the Sun than Neptune a decade earlier, a place where it would remain until February 11, 1999. While NASA could have maneuvered Voyager 2 to visit Pluto, there was one small hitch. The necessary trajectory would have slammed it right into Neptune.

Space and force

Navigating space is a tricky thing, as it’s a very big place, and things don’t work like they do down on a solid planet. On Earth, we’re able to maneuver, whether on foot, in a wheeled vehicle, or an aircraft, because of friction and gravity. Friction and gravity conspire to hold you or your car down to the Earth. In the air, they conspire to create a sort of tug of war with the force of lift to keep a plane up there.

When you take a step forward, friction keeps your back foot in place, and the friction allows you to use your newly planted front foot to move ahead. Note that this is why it’s so hard to walk on ice. It’s a low-friction surface.

The same principle works with cars (which also don’t do well on ice) with the treads on the tires gripping the road to pull you forward or stop you when you hit the brakes — which also work with friction.

Turning a car works the same way, but with one important trick that was discovered early on. If both wheels on opposite sides are on the same axle, turning the wheels does not result in a smooth turn of the vehicle. The axles need to be independent for one simple reason. The outside wheel has to travel farther to make the same turn, meaning that it has to spin faster.

Faster spin, lower friction, vehicle turns. While the idea of a differential gear doing the same thing in other mechanisms dates back to the 1st century BCE, the idea of doing it in wheeled vehicles wasn’t patented until 1827. I won’t explain it in full here because others have done a better job, but suffice it to say that a differential is designed to transfer power from the engine to the wheels at a relative rate dependent upon which way they’re aimed in a very simple and elegant way.

Above the Earth, think of the air as the surface of the road and an airplane’s wings as the wheels. The differential action is provided by flaps which block airflow and slow the wing. So… if you want to turn right, you slow down the right wing by lifting the flaps, essentially accelerating the left wing around the plane, and vice versa for a left turn.

In space, no one can feel you turn

When it comes to space, throw out everything in the last six paragraphs, because you don’t get any kind of friction to use, and gravity only comes into play in certain situations. Bookmark for later, though, that gravity did play a really big part in navigating the Voyager probes.

So, because no friction, sorry, but dog-fights in space are not possible. Hell, spacecraft don’t even need wings at all. The only reason that the Space Shuttle had them was because it had to land in an atmosphere, and even then they were stubby and weird, and even NASA engineers dubbed the thing a flying brick.

Without friction, constant acceleration is not necessary. One push starts you moving, and you’ll just keep going until you get a push in the opposite direction or you slam into something — which is just a really big push in the opposite direction with more disastrous results.

Hell, this is Newton’s first law of motion in action. “Every object persists in its state of rest or uniform motion — in a straight line unless it is compelled to change that state by forces impressed on it.” Push an object out in the vacuum of space, and it will keep on going straight until such point that another force is impressed upon it.

Want to turn right or left? Then you need to fire some sort of thruster in the direction opposite to the one you want to turn — booster on the right to turn left, or on the left to turn right. Want to slow down? Then you need to fire that thruster forward.

Fun fact: there’s no such thing as deceleration. There’s only acceleration in the other direction.

Also, if you keep that rear thruster going, your craft is going to keep on accelerating, and over time, this can really add up. For example, Voyager 2 is currently traveling at 15.4 kilometers (9.57 miles) per second — meaning that for it to take a trip from L.A. to New York would take five minutes.

Far and away

At the moment, though, this probe is 11.5 billion miles away, which is as long as four million trips between L.A. and New York. It’s also just over 17 light hours away, meaning that a message to and response from takes one day and ten hours.

And you thought your S.O. was blowing you off when it took them twenty minutes to reply to your text. Please!

But consider that challenge. Not only is the target so far away, but NASA is aiming at an antenna only 3.66 meters (12 feet) in diameter, and one that’s moving away so fast. Now, granted, we’re not talking “dead on target” here because radio waves can spread out and be much bigger than the target. Still… it is an impressive feat.

The more impressive part, though? We’re talking about technology that is over forty years old and still functioning and, in fact, providing valuable data and going beyond its design specs. Can you point to one piece of tech that you own and still use that’s anywhere near that old? Hell, you’re probably not anywhere near that old, but did your parents or grandparents leave you any tech from the late 70s that you still use? Probably not unless you’re one of those people still inexplicably into vinyl (why?)

But NASA has a track record of making its stuff last well beyond its shelf-life. None of the Mars rovers were supposed to keep on going like they have, for example, but Opportunity, intended to only last 90 days, kept on going for fifteen years, and the NASA Mars probes that actually made it all seem to last longer than intended.

In the case of Voyager, the big limit is its power supply, provided by plutonium-238 in the form of plutonium oxide. The natural decay of this highly radioactive element generates heat, which is then used to drive a bi-metallic thermoelectric generator. At the beginning, it provided 470 Watts of 30 volt DC power, but as of 1997 this had fallen to 335 Watts.

It’s interesting to note NASA’s estimates from over 20 years ago: “As power continues to decrease, power loads on the spacecraft must also decrease. Current estimates (1998) are that increasingly limited instrument operations can be carried out at least until 2020. [Emphasis added].”

Nerds get it done.

Never underestimate the ability of highly motivated engineers to find workarounds, though, and we’ve probably got at least another five years in Voyager 2, if not more. How do they do it? The same way that you conserve your phone’s battery when you forgot your charger and you hit 15%: power save mode. By selectively turning stuff off — exactly the same way your phone’s power-saver mode does it by shutting down apps, going into dark mode, turning off fingerprint and face-scan recognition, and so on. All of the essential features are still there. Only the bells and whistles are gone.

And still, the durability of NASA stuff astounds. Even when they’ve turned off the heaters for various detectors, plunging them into very sub-zero temperatures, they have often continued to function way beyond the conditions they were designed and tested for.

NASA keeps getting better. Nineteen years after the Voyagers, New Horizons was launched, and it managed to reach Pluto’s orbit and famously photograph that not-a-planet object only 9½ years after lift-off — and with Pluto farther out — as opposed to Voyager’s 12 years.

Upward and onward, and that isn’t even touching upon the utter value of every bit of information that every one of these probes sends us. We may leave this planet in such bad shape that space will be the only way to save the human race, and NASA is paving the way in figuring out how to do that.

Pretty cool, huh?

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.

Forces of nature

If you want to truly be amazed by the wonders of the universe, the quickest way to do so is to learn about the science behind it.

And pardon the split infinitive in that paragraph, but it’s really not wrong in English, since it became a “rule” only after a very pedantic 19th century grammarian, John Comly, declared that it was wrong to do so — although neither he nor his contemporaries ever called it that. Unfortunately, he based this on the grammar and structure of Latin, to which that of English bears little resemblance.

That may seem like a digression, but it brings us back to one of the most famous modern split infinitives that still resonates throughout pop culture today: “To boldly go where no one has gone before,” and this brings us gracefully back to science and space.

That’s where we find the answer to the question “Where did we come from?” But what would you say exactly is the ultimate force that wound up directly creating each one of us?

One quick and easy answer is the Big Bang. This is the idea, derived from the observation that everything in the universe seems to be moving away from everything else, so that at one time everything must have been in the same place. That is, what became the entire universe was concentrated into a single point that then somehow exploded outward into, well, everything.

But the Big Bang itself did not instantly create stars and planets and galaxies. It was way too energetic for that. So energetic, in fact, that matter couldn’t even form in the immediate aftermath. Instead, everything that existed was an incredibly hot quantum foam of unbound quarks. Don’t let the words daunt you. The simple version is that elements are made up of atoms, and an atom is the smallest unit of any particular element — an atom of hydrogen, helium, carbon, iron, etc. Once you move to the subatomic particles that make up the atom, you lose any of the properties that make the element unique, most of which have to do with its atomic weight and the number of free electrons wrapped around it.

Those atoms in turn are made up of electrons that are sort of smeared out in a statistical cloud around a nucleus made up of at least one proton (hydrogen), and then working their way up through larger collections of protons (positively charged), an often but not always equal number of neutrons (no charge), and a number of electrons (negatively charged) that may or may not equal the number of protons.

Note that despite what you might have learned in school, an atom does not resemble a mini solar system in any particular way at all, with the electron “planets” neatly orbiting the “star” that is the nucleus. Instead, the electrons live in what are called orbitals and shells, but they have a lot more to do with energy levels and probable locations than they do with literal placement of discrete dots of energy.

Things get weird on this level, but they get weirder if you go one step down and look inside of the protons and neutrons. These particles themselves are made up of smaller particles that were named quarks by Nobel Prize winner Murray Gell-Man as a direct homage to James Joyce. The word comes from a line from Joyce’s book Finnegans Wake, which itself is about as weird and wonderful as the world of subatomic science. “Three quarks for muster mark…”

The only difference between a proton and a neutron is the configuration of quarks inside. I won’t get into it here except to say that if we call the quarks arbitrarily U and D, a proton has two U’s and one D, while a neutron has two D’s and one U.

And for the first few milliseconds after the Big Bang, the universe was an incredibly hot soup of all these U’s and D’s flying around, unable to connect to each other because the other theoretical particles that could have tied them together, gluons, couldn’t get a grip. The universe was also incredibly dark because photons couldn’t move through it.

Eventually, as things started to cool down, the quarks and gluons started to come together, creating protons and neutrons. The protons, in turn, started to hook up with free electrons to create hydrogen. (The neutrons, not so much at first, since when unbound they tend to not last a long time.) Eventually, the protons and neutrons did start to hook up and lure in electrons, creating helium. This is also when the universe became transparent, because now the photons could move through it freely.

But we still haven’t quite gotten to the force that created all of us just yet. It’s not the attractive force that pulled quarks and gluons together, nor is it the forces that bound electrons and protons. That’s because, given just those forces, the subatomic particles and atoms really wouldn’t have done much else. But once they reached the stage of matter — once there were elements with some appreciable (though tiny) mass to toss around, things changed.

Vast clouds of gas slowly started to fall into an inexorable dance as atoms of hydrogen found themselves pulled together, closer and closer, and tighter and tighter. The bigger the cloud became, the stronger the attraction until, eventually, a big enough cloud of hydrogen would suddenly collapse into itself so rapidly that the hydrogen atoms in the middle would slam together with such force that it would overcome the natural repulsion of the like-charged electron shells and push hard enough to force the nuclei together. And then you’d get… more helium, along with a gigantic release of energy.

And so, a star is born. A bunch of stars. A ton of stars, everywhere, and in great abundance, and with great energy. This is the first generation of stars in the universe and, to quote Bladerunner, “The light that burns twice as bright burns half as long.” These early stars were so energetic that they didn’t make it long, anf they managed to really squish things together. You see, after you turn hydrogen into helium, the same process turns helium into heavier elements, like lithium, carbon, neon, oxygen, and silicon. And then, once it starts to fuse atoms into iron, a funny thing happens. Suddenly, the process stops producing energy, the star collapses into itself, and then it goes boom, scattering those elements aback out into the universe.

This process will happen to stars that don’t burn as brightly, either. It will just take longer. The first stars lasted a few hundred million years. A star like our sun is probably good for about ten billion, and we’re only half way along.

But… have you figured out yet which force made these stars create elements and then explode and then create us, because that was the question: “What would you say exactly is the ultimate force that wound up directly creating each one of us?”

It’s the same force that pulled those hydrogen atoms together in order to create heavier elements and then make stars explode in order to blast those elements back out into the universe to create new stars and planets and us. It’s the same reason that we have not yet mastered doing nuclear fusion because we cannot control this force and don’t really know yet what creates it. It’s the same force that is keeping your butt in your chair this very moment.

It’s called gravity. Once the universe cooled down enough for matter to form — and hence mass — this most basic of laws took over, and anything that did have mass started to attract everything else with mass. That’s just how it works. And once enough mass got pulled together, it came together tightly enough to overcome any other forces in the universe.  Remember: atoms fused because the repulsive force of the negative charge of electrons was nowhere near strong enough to resist gravity, and neither was the nuclear force between protons and neutrons.

Let gravity grow strong enough, in fact, and it can mash matter so hard that it turns every proton in a star into a neutron which is surrounded by a surface cloud of every electron sort of in the same place, and this is called a neutron star. Squash it even harder, and you get a black hole, a very misunderstood (by lay people) object that nonetheless seems to actually be the anchor (or one of many) that holds most galaxies together.

Fun fact, though. If our sun suddenly turned into a black hole (unlikely because it’s not massive enough) the only effect on the Earth would be… nothing for about eight minutes, and then it would get very dark and cold, although we might also be fried to death by a burst of gamma radiation. But the one thing that would not happen is any of the planets suddenly getting sucked into it.

Funny thing about black holes. When they collapse like that and become one, their radius may change drastically, like from sun-sized to New York-sized, but their gravity doesn’t change at all.

But I do digress. Or maybe not. Circle back to the point of this story: The universal force that we still understand the least also happens to be the same damn force that created every single atom in every one of our bodies. Whether it has its own particle or vector, or whether it’s just an emergent property of space and time, is still anybody’s guess. But whichever turns out to be true, if you know some science, then the power of gravity is actually quite impressive.