Sciency Words: Spaghettification (An A to Z Challenge Post)

April 22, 2017April 16, 2017 ~ J.S. Pailly ~ 8 Comments

Today’s post is a special A to Z Challenge edition of Sciency Words, an ongoing series here on Planet Pailly where we take a look at some interesting science or science related term so we can all expand our scientific vocabularies together. In today’s post, S is for:

SPAGHETTIFICATION

I have noted that in thought experiments involving black holes, it is traditional to enter the black hole feet first. Therefore, let’s jump feet first into a black hole and try to imagine what happens.

According to a recent paper in the Journal of Physics Special Topics (my all time favorite physics journal), there’s a reasonable chance you’d remain conscious, at least for a while, after crossing the black hole’s event horizon.

That is, assuming the black hole’s mass is greater than 19,000 solar masses. Apparently the more massive a black hole, the longer you’ll last before you pass out. The authors of the paper also assume you were in relatively good health before entering the black hole.

As you continue to fall toward the center of the black hole—a point of infinite density called the singularity—you’ll be accelerating so fast that you’ll start to lose consciousness. The human heart really struggles with pumping blood when you’re experiencing such high G-forces.

And honestly, that’s probably for the best, because things are about to get super weird. The gravity inside a black hole is so intense that, in essence, your feet are falling significantly faster than your head, and the rest of your body is being stretched out in between.

As you keep falling toward the singularity, you become so stretched and elongated that you look less and less like a person and more and more like a spaghetti noodle. And so this process is called—I kid you not—spaghettification.

Next time on Sciency Words: A to Z, if you didn’t like death by spaghettification, how do you feel about death by thagomizer?

P.S.: Other recent papers from the Journal of Physics Special Topics include:

I think you can see why this is my all time favorite physics journal.

Sciency Words: Reduction (An A to Z Challenge Post)

April 21, 2017April 16, 2017 ~ J.S. Pailly ~ 10 Comments

REDUCTION

In his book Atom: Journey Across the Subatomic Cosmos, Isaac Asimov writes:

It often happens that a poor name is given to an object or a phenomenon to begin with, either out of ignorance or out of bad judgment. Sometimes, it can be changed in time, but often the ill-chosen name is used so commonly by so many that it becomes inconvenient or even impossible to change it.

Hank Green says much the same thing at the beginning of this episode of Crash Course: Chemistry on oxidation and reduction.

I wish someone had told me this in high school chemistry, because I could never make sense out of reduction. The name confused me too much, because it means the opposite of what it should mean.

Some atoms are naturally greedy for electrons. These atoms are called oxidants.

And some atoms are naturally well inclined to give electrons away. These atoms are called reductants.

When a reductant gives an electron to an oxidant, the reductant is said to have been oxidized. And when an oxidant gains an electron from a reductant, the oxidant is said to have been reduced.

Yes. The gaining of an electron is called reduction, a word typically associated with the losing of something. Just… how even? This is one of the most fundamental reactions in all of chemistry. No wonder chemistry is so notoriously hard!

Apparently long ago, it was observed that some substances become lighter after undergoing a chemical reaction. Hence, reduction. We now know the substances in question were gaining electrons (which weigh practically nothing), while incidentally losing other, heavier things in the form of gases. But how were scientists of the 18^th Century supposed to know that?

We can take some consolation in the fact that when a chemical substance gains electrons, its oxidation number goes down. So in that sense, the word reduction doesn’t seem completely stupid.

But Asimov and Green hit upon a key insight on how scientific terminology works—or rather, why it doesn’t always work. When you really delve into the scientific lexicon, you find this naming before understanding trend everywhere. As a result, we’re now stuck with a ton of confusing, counterintuitive names for important scientific concepts.

Next time on Sciency Words: A to Z, we’ll jump feet first into a black hole.

Sciency Words: Quantum (An A to Z Challenge Post)

April 20, 2017April 16, 2017 ~ J.S. Pailly ~ 4 Comments

QUANTUM

Quantum physics is the study of atoms and subatomic particles, and it get’s pretty weird. It’s almost as though all these quantum particles are playing a joke on us.

However, the quantum world isn’t completely loony. It’s not a place where anything goes. There are rules to how quantum particles behave; it’s just that these rules fly in the face of what we humans would call common sense.

But for our purposes here on Sciency Words, we won’t get into all those common-sense-defying rules. We’re more interested in the word quantum itself. How did this poor, innocent word get itself entangled with such a weird, wacky branch of science?

The story begins with Einstein (as so many things do). In one of his 1905 “Miracle Year” papers, Einstein needed a word to describe a particle of light. Einstein was arguing that light isn’t a continuous wave, as had previously been thought, but is actually made up of tiny particles (we now know light is both a particle and a wave at the same time, but I said we wouldn’t get into that common-sense-defying stuff).

Einstein chose the word quantum (plural: quanta) for his light particles. It’s a word closely associated to words like quantity or quantifiable. Basically, a quantum is something you can count. Specifically, it’s something you have to count in whole numbers, because you’re dealing with discrete units of a substance that cannot be divided into smaller units of the same substance.

Einstein’s light quanta would later be renamed photons, but the usage of quantum/quanta to describe other indivisible units at the atomic and subatomic level would continue.

Ultimately, this whole field of study would be dubbed quantum mechanics thanks to two papers published in 1925, the first by Max Born and Pascual Jordan, and the second by Max Born, Pascual Jordan, and Werner Heisenberg. At that time, all this quantum stuff was already pretty strange, and it would just keep getting stranger going forward.

And yet even today, modern quantum physics has stayed somewhat true to the root meaning of the word quantum, because it still deals with a lot of whole numbers. I should mention, of course, that there are plenty of non-whole numbers involved, such as Planck’s constant, and then there’s the whole matter of fermions and their non-integer spins (someone will yell at me in the comments if I don’t acknowledge that stuff).

But whole numbers and whole number ratios still play an extremely important—some might even say weirdly important—role in quantum physics, because you can’t have half an electron or half a photon or half a quark. You’re dealing with particles you must count in whole numbers, because they cannot be divided into anything smaller.

Next time on Sciency Words: A to Z, what do you do when a word means the opposite of what it’s supposed to mean?

Sciency Words: Planet (An A to Z Challenge Post)

April 19, 2017April 16, 2017 ~ J.S. Pailly ~ 37 Comments

PLANET

In 2006, the International Astronomy Union approved a new, official definition of planet, and Pluto didn’t make the cut. Word has it Pluto took the news well.

The I.A.U.’s concern at the time was that more and more small, Pluto-like objects were being discovered, making Pluto seem less like the ninth planet and more like the first of some new class of thing.

To be fair, the I.A.U. did try to come up with a planet definition that would include Pluto while excluding the dozens or perhaps hundreds of other objects potentially out there. But it just didn’t work out.

So to meet the official, I.A.U. sanctioned definition, an astronomical body must meet three requirements:

It must orbit the Sun.
It must be spherical, due to the pull of its own gravity.
It must have cleared its orbital path of debris (this is the part of the planet test that Pluto failed).

Of course, if a definition can be changed once, it can be changed again. Recently, a group of six NASA scientists—specifically, six scientists from NASA’s New Horizons mission to Pluto—put forward a new proposal, which reads:

A planet is a sub-stellar mass body that has never undergone nuclear fusion and that has sufficient self-gravitation to assume a spheroidal shape adequately described by a triaxial ellipsoid regardless of its orbital parameters.

In other words, if it’s round, and it’s not a star or wasn’t a star at some point in the past, then it’s a planet. Under this new definition, Pluto’s back in the planet club! And so is the Moon, weirdly enough, along with many other moons elsewhere in the Solar System. In fact, the new definition would reclassify over one hundred Solar System objects as planets—possibly more than that.

The next I.A.U. general assembly meeting will be held in August, 2018. If they’re going to change the definition of planet again, that’s when they’ll do it. But I very much doubt it’ll happen.

Even though this is probably a lost cause, I want to say something in defense of the New Horizons team’s proposal. The strongest objection seems to be that moons should not be planets. I get that, but in my mind any world that I can picture myself standing on or walking on… I don’t know, that just feels planet-y to me.

I frequently catch myself calling Titan and Europa planets, even though they’re moons. Same for Pluto, Eris, Ceres, and all the other objects currently in the dwarf planet category. And I can’t help myself, but I keep calling Endor from Star Wars a planet, even though it’s specifically referred to multiple times in dialogue as a “forest moon.” All of these places—even fictional moons like Endor—feel planet-y to me.

And yes, even the Moon—the most quintessential moon of them all—has a certain planet-esque quality to it when I imagine myself living there, walking around, going about my daily business. I could get used to the Moon being a planet.

Next time on Sciency Words: A to Z, we’ll shrink from planet-scale to the scale of subatomic particles, and we’ll find out what’s so quantum about quantum mechanics.

Sciency Words: Organic (An A to Z Challenge Post)

April 18, 2017April 16, 2017 ~ J.S. Pailly ~ 18 Comments

ORGANIC

Sometimes scientists name things before they fully understand them. Such is the case with the entire field of organic chemistry.

Organic chemicals are called organic because, it was once thought, they could only be produced by living organisms. There was something almost mystical, almost magical about living things, scientists believed. They spoke of a mysterious “vital energy” without which certain chemical reactions simply could not occur.

Then in 1828, Friedrich Wöhler synthesized urea–a key ingredient in urine–in a test tube. That sounds kind of gross, but it was a monumental achievement in the history of science.

Sort of like how Newton showed that the same laws of physics which apply here on Earth also apply to the planets and stars, Wöhler’s urea synthesis demonstrated that the same laws of chemistry apply to both living and non-living matter.

The group of chemicals that scientists had been calling “organic” do have at least one thing in common: carbon. They all incorporate carbons atoms, typically carbon atoms bonded to other carbon atoms or to hydrogen atoms (certain simple carbon compounds like CO₂ are generally not considered organic).

Perhaps some other name would be more appropriate for these complex carbon molecules, but scientists had been calling them organic chemicals and talking about organic chemistry for a while. The name had already stuck.

I suppose we could rationalize the modern usage of organic by saying we organisms need organic chemicals to live; but thanks to Wöhler, we now know organic chemicals do not need us organisms in order to exist.

Next time on Sciency Words: A to Z, let’s see if we can get Pluto’s planet status back.

Sciency Words: Negatron (An A to Z Challenge Post)

April 17, 2017April 17, 2017 ~ J.S. Pailly ~ 11 Comments

NEGATRON

In 1896, J.J. Thomson discovered the electron: a subatomic particle with a negative electric charge. Then in 1932, Carl Anderson discovered a new kind of electron. It was exactly the same as the old one, except it had a positive charge.

Anderson decided to name this new kind of electron a positron, and he wanted to retroactively rename the old one a negatron.

When matter and antimatter particles like these get into arguments, they always end the same way: the particles annihilate each other. Which is why it’s so important for nuclear physicists to keep matter and antimatter apart.

Anyway, under Carl Anderson’s naming scheme, we’d still get to use the word electron, but electron would be sort of like a genus name, with positron and negatron being two species of electron. That’s a nifty way to think about matter/antimatter pairs, if you ask me. Too bad the idea didn’t stick.

Or so I thought….

To my surprise, I was able to find negatron in a dictionary—a standard dictionary, not even a special dictionary of science. To my further surprise, spell-check recognizes negatron as a word. According to Google ngrams, the word is still in use, and when I did a search on Google Scholar, I found a ton of papers—recent papers—using the term in relation to nuclear physics.

So that subatomic particle pictured above—whether it likes it or not, it really is a negatron.

Next time on Sciency Words: A to Z, it’s dangerous to name a concept before you fully understand it.

Sciency Words: Metallicity (An A to Z Challenge Post)

April 15, 2017April 11, 2017 ~ J.S. Pailly ~ 11 Comments

METALLICITY

Astronomers. All the other scientists had a meeting, and they all agree: there’s something wrong with those astronomers. For some reason, astronomers do not understand what is or is not a metal.

According to astronomers, the only elements that aren’t metals are hydrogen and helium.

Now it does make sense for hydrogen and helium to be special in astronomers’ eyes. By mass, something like 75% of the observable universe is hydrogen. Helium makes up almost all of the remaining 25%. And the hundred-plus other elements on the periodic table? All combined, all that other stuff constitutes less than 1% of the observable universe.

So for astronomers, it’s convenient to have a word that lumps all this “other stuff” together. But why does that word have to be metal? I’ve never found a wholly satisfactory answer for this, but I do have a personal theory.

Turns out that in technical shorthand, the amount of “other stuff” in a star is represented as [Fe/H]. That’s the chemical symbols for iron (Fe) and hydrogen (H). In other words, the amount of “other stuff” is quantified as a ratio (sort of) of iron to hydrogen (the math is a little more complicated than a simple ratio, but I won’t to get into that here).

I’m guessing that out of all the non-hydrogen, non-helium atoms you might expect to find in a star, iron must be the easiest—or at least one of the easiest—to identify with a spectroscope, and thus iron serves as a convenient proxy for everything else.

The quantity represented by [Fe/H] is called metallicity. Everyone would agree that iron is a metal, so that makes sense. But since metallicity actually tells us more than just the iron content of a star—since it also gives us a sense of how much carbon and silicon and argon etc is in that star—suddenly the word metallicity is covering metals and non-metals alike, in a way that comes across as very odd to everyone who isn’t an astronomer.

Next time on Sciency Words: A to Z, an electron by any other name would still be negatively charged.

Sciency Words: Libration (An A to Z Challenge Post)

April 14, 2017April 10, 2017 ~ J.S. Pailly ~ 19 Comments

LIBRATION

The Moon is tidally locked to the Earth, meaning one side is always facing toward us and the other side is always facing away. Except this tidal locking isn’t perfect. The Moon rocks back and forth just a little bit.

The technical term for this is libration. It comes from a Latin word meaning balance. In the visual simulation above (courtesy of Wikipedia), we can see the phases of the Moon on fast-forward. We can also see that the Moon moves a little closer to us and then a little farther away, due to its elliptical orbit.

And if you watch closely, you can see the Moon rocking or swaying back and forth. If you’re having trouble seeing it, I recommend picking a surface feature—a crater, perhaps—and following it with your eyes.

Of course our Moon isn’t the only moon that librates. I first learned about libration from a paper about Enceladus, a moon of Saturn.

Thanks to the Cassini mission, we were able to get extremely precise measurements of Enceladus’s libration, and we discovered Enceladus librates a lot. Like, a whole lot.

Enceladus librates so much that it cannot be solid all the way through. Instead, there must be a vast ocean of liquid water sloshing around inside, with only a thin, icy crust floating on top.

That’s a big deal because with all that liquid water, there’s a chance that maybe—just maybe—Enceladus could support life.

Next time on Sciency Words: A to Z, we’ll talk about metal. Everyone knows what metal is. Everyone except astronomers.

Sciency Words: Kilogram (An A to Z Challenge Post)

April 13, 2017February 4, 2019 ~ J.S. Pailly ~ 18 Comments

KILOGRAM

We’ve already met the International Astronomy Union and the International Commission on Stratigraphy. There are lots of international science organizations like these, and a big part of their job is to set official definitions for scientific terms, so that the use of these terms doesn’t cause confusion in scientific discourse.

Today we’ll get to know the International Bureau of Weights and Measures, which is in charge of defining all the units of measurement for the metric system. Originally, all the metric system units were based on physical prototypes. So for example, there was a prototype meter stick. A meter was equal to however long that meter stick was, and all other meter sticks had to be cut to match the prototype.

And if something happened to the prototype meter stick, if it got shorter or longer somehow, then by definition the meter would get shorter or longer too. As you can imagine, this caused problems.

Over the years, the International Bureau of Weights and Measures has been redefining all the metric system units using universal constants like the speed of light or other fixed values like the triple point of water. They’ve been able to do this for every unit except one: the kilogram.

The kilogram is still based on a protoype: a cylinder of platinum/iridium alloy made in the late 1880’s.

Actually, most people call it Le Grand K because it’s located in France. On very, very rare occasions, Le Grand K is taken out of its high security vault and compared to other weights, which are then used to calibrate measuring instruments all around the world.

Unfortunately, it seems Le Grand K has lost a little weight. A very, very little amount of weight. Its total mass appears to have decreased by 0.05 milligrams. You’d need to be doing some extremely precise measurements before the change in Le Grand K’s mass would matter, but of course there are scientists and engineers out there who are doing those kinds of extremely precise measurements. Or at least they’re trying to.

But a fix for the kilogram may be on its way, using Planck’s constant and Einstein’s famous E = mc² equation. Assuming the math checks out, the International Bureau of Weights and Measures might be able to retire Le Grand K by the end of 2018.

Next time on Sciency Words: A to Z, let’s get ready to librate!

Sciency Words: Juno (An A to Z Challenge Post)

April 12, 2017April 10, 2017 ~ J.S. Pailly ~ 12 Comments

JUNO

The current NASA mission exploring Jupiter is named Juno. That stands for Jupiter Near-polar Orbiter. Except not really. I’m pretty sure someone came up with that acronym long after the Juno mission was already named.

According to a press release from 2011, NASA named its Jupiter mission after the Roman goddess Juno (a.k.a. Hera), the wife of Jupiter (a.k.a. Zeus). Now if you’re at all familiar with Greek and Roman mythology, you know Jupiter and Juno didn’t exactly have an ideal marriage.

In that 2011 press release, NASA reminds us of one specific story in which Jupiter tried to hide his “mischief” behind a veil of clouds. Of course the whole veil of clouds routine didn’t work, and Juno saw right through her husband’s trickery.

NASA was kind of brilliant with this specific mythological reference. It’s a lot cleverer than some silly acronym.

The Juno space probe is equipped with ultraviolet and infrared cameras, which can see through the top most layers of Jupiter’s atmosphere. Even better, Juno is carrying instruments for studying Jupiter’s magnetic field, which will indirectly tell us more about the planet’s core. And Juno will be mapping the planet’s gravitational field, which will reveal how mass is distributed in the planet’s interior.

In other words…

Next time on Sciency Words: A to Z, what’s the total mass of a kilogram?