Category Archives: Science

Ice is Nice!!!

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Today, I spent a while in my front yard shoveling the foot or so (let’s use 3 decimeters…that sounds much cooler) snow out of my driveway.  As I was LOLing at my neighbors who were all stuck in snow drifts because it is apparently against the law to plow my street, I started to think about how ridiculous snow is.  One day you go outside and there’s a blanket of ice shards as far as the eye can see.  It really is a bizarre phenomena.  So, it seemed fitting to go on about how awesome ice actually is.

Thank Goodness for Hydrogen Bonding

The thing that makes ice specifically, and water in general, pretty awesome is the hydrogen bond.  Regardless of how much science you’ve been exposed to in your life, everyone knows that water is H2O; two hydrogen molecules attached to a single oxygen molecule.

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The whole idea of bonding in chemistry of the sharing of electrons.  Hydrogen has one lone electron and an inferiority complex; it really wants to be like its buddy helium, which has two electrons.  It wants this because, with two electrons, it will be essentially non-reactive (the outer shell of electrons will be full), and this is energetically favorable.  Nature enjoys things that are energetically favorable.  Likewise, oxygen, which has six eight electrons, really wants to be like its buddy neon because, like helium, neon’s outer shell of electrons is full, making it fairly non-reactive.  So, when two hydrogen atoms and one oxygen atom get together, they strike a deal.  Oxygen, the ring leader, says “Tell you what…if you two hang out close enough to me, I’ll let you ‘borrow’ a couple of my electrons, so you can be like helium, and in return, you’ll let me ‘borrow’ your electrons so I can be like neon…win-win for everyone!”  Thus, we have water.

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However, the shape of water is important.  The fact that it is bent slightly makes the charge distribution just a little asymmetric and the molecule acts like something called a dipole.  One the whole, the molecule as a whole is electrically neutral.  But, since the positive and negative charges are separated a bit, the negative part can be attracted to a positive charge nearby and the positive part can be attracted to a negative charge nearby.  This will cause the molecule to rotate into alignment with an electric field.  Indeed, this is how your microwave works; as the microwaves pass through the object and the polarity of the wave switches back and forth from positive to negative, the water dipoles rotate back and forth, creating a kind of friction that heats the material.

If you put a bunch of water molecules together, they don’t just float around in any old way.  The positive parts of each molecule attract the negative parts of other molecules.  This action is known as hydrogen bonding.  It is much weaker than the covalent bonding that holds the water together, but it is responsible for most of the awesome properties of water and ice.  For instance, water is “wet” because of hydrogen bonding…hydrogen bonds are created between the water and the molecules of whatever it’s on,  making it atomically “sticky” when you get it on your skin.  If you’ve every played with mercury from a thermometer, you may have noticed that it doesn’t wet anything, it just rolls around.  This is because there are no hydrogen bonds present.

Fantastic…but why does this make ice nifty?  The molecules in liquid water have enough kinetic energy to constantly break the hydrogen bonds and move around.  This is what makes water, well…water.  It’s viscous because of hydrogen bonds, far more viscous than it would be without them.  If you add heat, the molecules speed up, gaining kinetic energy, and eventually all hydrogen bonds break and the molecules fly apart…STEAM!!!  In fact, one interesting fact is that if hydrogen bonding did not exist, liquid water would boil at around -90°C!  Considering how important water is to life and its development, it’s a good thing this is not the case.

If you remove heat, the molecules loose energy and hydrogen bonding becomes a more dominant process.  At the freezing point, the molecules no longer have enough energy to break the hydrogen bonds and “flow”.  The water then crystallizes into ice.

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The hydrogen bonding forces the molecules into layers of rippled hexagons; I added the little copper rods in the picture above to represent this bonding.  This brings be to something waaaaaay cool.

Snowflakes

The hexagonal structure imposed in normal ice is what is primarily responsible for the hexagonal symmetry seen in snowflakes.  A snowflake is an individual crystal of ice that forms when a small droplet of water in the atmosphere supercools around a nucleus, something like a dust particle or our ever-present smog.  Once this nucleus forms, the surrounding vapor droplets freeze and aggregate onto the crystal.  However, the hydrogen bonding imposes symmetry onto the deposition…so we get the familiar snowflake.

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This image was taken of an ice crystal with a scanning electron microscope; the colors were added afterwards to increase contrast.

So, the thing that really makes water interesting is this hydrogen bonding.  Without it, we wouldn’t have liquid water at the normal temperature of the Earth and we wouldn’t have bazillions of amazing snowflakes with unique shapes falling onto our tongues…and onto our walkways and roads…at 2 am…that we have to plow and shovel.

There is another interesting consequence to hydrogen bonding, though.  As the water freezes and takes on this hexagonal structure, the overall effect is to push the molecules away from each other into the rigid pattern of ice.  The result is that ice is less dense than liquid water and, as we all know, floats in water.  This is actually quite remarkable; there are very few substances whose solid phase is less dense than it’s liquid.  An example of a very not-water example of something else that has this property, check out gallium.

This fact has had profound impact on Earth.  If ice was like every other solid and was more dense, then the freezing process would start from the bottom up.  If this were the case, then the oceans, lakes, and streams of our planet would freeze from bottom up, destroying life.  The hydrogen bonding in ice is what has made it possible for life evolve; without it, all of our water would have frozen long ago and life could never have developed in the oceans for billions of years.  Erosion from freezing and thawing would also not exist, as water would not expand as it froze.  Our landscape would look very different.

There’s More Than One Type of Ice

Several years ago, I got around to reading the novel “Cat’s Cradle” by Kurt Vonnegut.  It revolves around the creating of this material known as ice-nine, which is a weapon of mass destruction that can turn all of the liquid water on Earth (and in your body) to ice at a much higher temperature than normal.  It’s a pretty good read, albeit bizarre.

After getting through it, I was looking up ice-nine on the Interwebs to learn about it’s cultural references when I can across this line line at the top of its Wikipedia article which kind of blew my mind:

“This article is about the fictional material in Cat’s Cradle. For the metastable form of solid water, see Ice IX.”

The ice that we all know and love is actually only one possibility.  It’s the form that we experience because the conditions of it’s formation, namely pressure and temperature, are common to Earth.  However, it isn’t the only kind of water ice.  In fact, there are more than a dozen forms of ice; “normal” ice is referred to as Ice 1h since is hexagonal.  There are all sorts of crazy forms…and they have wacky properties.

Ice 1c, for instance, doesn’t have a hexagonal structure. Instead, it has the same cubic structure as diamond and forms in the upper atmosphere in small amounts.

Ice XI is probably the coolest (haha) form.  It is likely the most common form of ice, because it is actually more stable than normal ice.  However, it only forms below 72K, which is colder than liquid nitrogen.  Despite this, we have found some in Antarctica under the right conditions, namely pressure deep below the surface.  Crystalline water in space and on the surface of places like Jupiter and Saturn’s moons is most likely this form.  What’s really interesting is that Ice XI is a type of material known as a ferroelectric.  You’re all familiar with a ferromagnet, it is a material that can hold a permanent magnetic moment, which is responsible for permanent magnets.  A ferroelectric can hold a permanent electric polarization.  This means that the material as a whole would not be electrically neutral.  Crystals of Ice XI floating in space would attach each other electrically, similar to the idea of static electricity, and would be “sticky”.  It is thought that this contributed to holding together enough material to allow the formation of the icy bodies in the solar system, such as comets.

So, ice is pretty awesome.  If it wasn’t for it’s specific properties, life and, perhaps, the entire planet, would not exist.  We wouldn’t have comets and we wouldn’t have snowflakes (at least not the awesome ones we have now).  I am happy, though, that the ice on Earth isn’t more exotic…it would suck even more to shovel out of my driveway.

“Gigantic multiplied by colossal multiplied by staggeringly huge…”

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I have been watching a brilliant show produced by the BBC called “Wonders of Life”, a 5-part series about the origins and functionality of life, narrated by Dr. Brian Cox, whose mouth my wife takes issue with.  As you can imagine, the program starts with a description, using the current scientific wisdom, of the beginning of life on Earth and, indeed, anywhere.  I have no intention (at this point, anyway), to descend into a discussion on the origin of life.  To quote Neal Stephenson’s Cryptonomicon, “let’s set the existence-of-God issue aside for a later volume, and just stipulate that in some way, self-replicating organisms came into existence on this planet and immediately began trying to get rid of each other, either by spamming their environments with rough copies of themselves, or by more direct means which hardly need be belabored.”  But, there is a point that is made in debates about the origin of life that I would like to address, as it is frequently on my mind.

A common argument against life “just happening” seems to be that the complexity that exists today simply could not have randomly occurred, presumably over the given timescale. It’s like digging up a naturally occurring pocket watch or monkeys with typewriters creating a Shakespeare sonnet.  As I see it, a core issue here is the human mind’s lack of ability to comprehend large amounts of anything: time, money, number of things, etc.  As a scientist, I have to deal with quantities that are completely beyond everyday experience all the time…so ridiculous, in fact, that we had to invent scientific notation to express the numbers because words just fail.  Archimedes, the Greek badass that brought us things like the screw and the lever, pondered huge numbers in his work title The Sand Reckoner, where he conjectured that the grains of sand on the beaches of Sicily were infinite.  The Hitchhikers Guide to the Galaxy has this to say about infinity: “Bigger than the biggest thing ever and then some. Much bigger than that in fact, really amazingly immense, a totally stunning size, real ‘wow, that’s big’, time. Infinity is just so big that by comparison, bigness itself looks really titchy. Gigantic multiplied by colossal multiplied by staggeringly huge is the sort of concept we’re trying to get across here.”  Are they really infinite?  Well, no…but the number is so ridiculously huge that they are uncountable.  We have words and concepts, but we can’t really connect them to reality without really digging in and calculating something or generating a sequence of “things” to put it in perspective.

Take, for example, the chemical quantity known as the mole.  All matter is made up of atoms, but the number of atoms in “stuff” is incomprehensibly large.  The mole was created to scale that huge number down to something manageable.  One mole of “things” is equal to 6.02e23 items.  The “e23” just tells you how many times you multiply by 10.  So, 6.02e23 is equivalent to  602,000,000,000,000,000,000,000 things.  That’s a stupid amount of things.  How stupid?  Here’s an exercise to help put it in perspective.

I went into my wife’s office an snagged a random romance novel…“Slightly Sinful” by New York Times best-selling author Mary Balogh.  Not my thing, but anything for science!  Busting out my ruler, which I have since placed in a more accessible location since the last time I measured something, I find that the average area covered by a single letter on any given page is about 2 mm².  The page itself has dimensions 10.5 cm wide by 17.5 cm high, which gives an area of 183.75 cm².  If the page was completely packed with letters, each page would contain 6589 letters; more realistically, given indentation, spacing, margins, and empty space, 1500 letters per page is a reasonable estimate.  Now, the book has 355 pages, which means there are approximately 532,500 letters in this book.  So far so good…

This book is 2.5 cm thick.  Given that a mole is stupid huge, we need a large distance to work with…like the distance from the Earth to the Moon!  This distance, from surface to surface, is 376,292 km.  Thus, if you were to stack up copies of “Slightly Sinful” from the surface of the Earth to the surface of the Moon, you would have 15,100,000,000 books in the stack, that’s 15.1 billion books.  Side note: if you bought these books for the list price of $6.78, the national debt ($16.7 trillion) would buy you 163 of these Earth-Moon stacks…New York Times best-selling author indeed.

Each stack of books gives us 8.04e15 letters.  Now, create that stack 74, 875,622 times (!!!), and you will have one mole of letters.  If you were to count the books, not the letters, just the books, at a rate of 1 per second, it would take roughly 36 billions years, almost three times the age of the universe.  If you were to stack them up in a single stack, that stack would extend 28 trillion miles.  Voyager 1, of which there has been much hoopla as of late, wouldn’t even be halfway up stack by now.

Damn…

When you look on the Periodic Table, you see stuff like this:

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In the top-right of the square is the atomic mass of iron, 55.847.  This is the number of grams of iron you need to collect to have one mole of iron atoms.  Now, this…

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…is a cool nail that I inherited from my dad’s garage a few months ago.  It has a mass of just over 40g.  So, there are as many atoms of iron in this nail as there are letters in 54 million stacks of “Slightly Sinful” that reach from here to the Moon.

Again I say, damn…

To carry on the ridiculousness, consider that the Earth’s core is about 0.5% the total mass of the Earth itself and is comprised almost entirely of iron.  The mass of the Earth is about 6e24 kg, therefore the core is a lump of iron with a mass of about 3e22 kg.  Divide that by the mass of my bitchin’ nail, an you get 7.5e23.  So, there is about 1 mole of nails in the Earth’s core.  Which means there is a mole of mole’s worth of iron atoms!!!

Continuing on, ask yourself where does all of the iron come from?  Supernovae!!  It is formed in the cores of superheavy stars and then blown out into the Universe, where it accretes due to gravity and eventually forms planets like ours.  There is a debate, but the average amount of iron ejected into space in a supernova is projected to be near 0.2 solar masses, that is 20% the mass of the Sun.  The mass of the Sun is a whopping 2e30 kg!!  That’s 4e29 kg of iron per supernova…13 million moles of nails!!

Current estimates place the number of stars in the observable Universe at about 1e24…there’s 10 moles of stars!!!  Only about 3% of stars will be massive enough to die in a supernova.  Consider that the Universe is estimated to be about 13.7 billions years old and stars that are massive enough to supernova have a lifespan, say, of around a billion years (a high estimate).  So, it is estimated that there have been at least 2 generations of stars in the universe before the current crop, given the amount of time it takes to accrete enough mass to make a star in the first place.  So, 3% of the current number of stars is about 3e21 stars.  If each generation had the same number of stars supernova, then 6e21 stars have blown up, each injecting 4e29 kg of iron into the Universe.  That is 2.4e51 kg of iron…that is almost 1 million moles of moles of nails!!!!!!

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This exercise got really, really stupid a long time ago.  The point is that people have such difficulty understanding ridiculously large numbers that it is hard to trust yourself when you start working with them.  When you start writing down numbers that have 51 zeroes on the end, you are obviously well beyond common experience.  When science starts talking about things that involve such large quantities, it is really difficult for people who aren’t comfortable with them to understand.  It’s hard to imagine the amount of water in the ocean (1,386,000,000 cubic km), the distance to the nearest star (39,900,000,000,000 km), the number of neurons in the human brain (100,000,000,000 cells), or the amount of carbon dioxide humans put into the atmosphere each year (26,000,000,000 kg).  And yet, we have conversations about these types of things all the time.

Back to my original inspiration, when one talks about the origin of life as having randomly occurred because one cosmic ray hit one molecule in the ocean just right so that it formed the amino acid need to self-replicate, that seems completely impossible.  But, consider the fact that you had an entire ocean’s worth of chemicals “steeping” for a billion years being bombarded by cosmic rays in an era well before there was any kind of atmospheric shielding to protect the surface.  One mole of reactions could have easily have occurred…maybe, nigh probably, more.

My ultimate point here is not about the origin of life.  What I want to convey is the simple fact that our everyday notions of number an probability just don’t cut it when we talk about things on geologic timescales and in quantities that defy language.  Am I an expert on such existential things as how life began?  No.  But, I am comfortable with ridiculous quantities that one encounters when discusses it.

The question, then, is this: did “God” have to create life on Earth?  Maybe he just put the pot in the oven and let the soufflé rise on it’s own…

Heavy Metal

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As you may have seen, scientists have now confirmed the existence of element 115, temporarily (and amusingly) named ununpentium.  If you haven’t heard, which wouldn’t be surprising since it doesn’t involve twerking, socialism, gun control/violence, or chemical weapons, then behold this article to find out more.

It’s not at all surprising that 115 exists.  After all, the atomic Tetris game that is the Periodic Table, created by Dmitri Mendeleev in 1869 (a Russian…coincidence?), pretty much guarantees that an element would be found there.  Indeed, 114 and 116 had already been discovered, long enough ago that have “real” names: flerovium and livermorium.  Personally, I liked ununquadrium and ununhexium, but that’s just me.

So, the question is why do this?  Why spend the time to find something that is most likely already there and extremely unstable?  After all, these experiments are costly and time-consuming.  The original experiment that was performed to discover 115 in the first place involved bombarding an americium target (LOL element names) with energized calcium nuclei for a solid month!  During this process, they discovered 4 atoms of 115, a fact they only knew due to the radiation it gave off as it decayed since the lifetime of these atoms is measured tens of milliseconds.

The simple answer: because…SCIENCE!

You’ve no doubt heard Sir Edmund Hilary’s famous quote when asked why climb Everest: “Because it’s there.”  Finding 115 is kind of like that.

There you are, some mad scientist in an underground bunker, looking at your periodic table.  Your OCD keeps you fixated on the missing square between 114 and 116.  You can’t stop staring.  You MUST fill in the hole.

Now, the actual discovery wasn’t that ridiculous, but it highlights the essence of science, that it is a process to answer questions about Nature.  Science can pretty much be boiled down to  the following: “I wonder if X?”, experiment, “Yes/No”.  Simple asking the question “Does element 115 exist?” begs science to answer.

The complex answer: because discovering an element is the ultimate form of creativity

Think about it.  Human beings have an innate creative impulse.  We developed our brains over the eons so that we could build tools and structures of ever-increasing complexity.  Well, nuclear physics is the ultimate Erector Set.

Everything in the universe is constructed from 100-some-odd elements on the Periodic Table.  Take eleven protons, mix them with a few neutrons and you get sodium, a light, silver-colored metal.  Take 17 more protons, throw in a few more neutrons, and you get chlorine, a wispy, corrosive, green gas.  But, take those two Lego bricks and snap them together and you get table salt, sodium chloride.  Snap sodium together with fluorine instead, the element just above chlorine on the table, and you get sodium fluoride, the key ingredient in toothpaste.  Add a couple of extra neutrons to that fluorine and make it a different isotope and now you have the dye they use in a PET scan.  You can build anything with the right combination of atoms.  So, who wouldn’t want to add a new piece to the toybox?  It would be like a painter coming up with a hitherto unknown color and painting with it.  Which brings me to the most popular reason…

The capitalist answer: with a new element, we could make new things

Most of the super-heavy elements, everything past uranium on the table, are unstable and disintegrate in a matter of hours, if not seconds.  Needless to say, a material that turns into something else in a few seconds isn’t very useful.  These heavy atoms are unstable because of the immense energy that is required to hold their nuclei together.  They are simply too large to hold themselves together and they break apart spontaneously, or sometimes due to collisions, into smaller, lighter elements.

There is a, however, a theoretical expectation of something called the “island of stability”, a part of the periodic table where super-heavy elements are symmetric and efficient enough to last for days, even years, rather than seconds.  This “island” is expected to appear around element 120, unbinilium (I love these names).  So, scientists keep pushing the envelope to reach this stable region.

Who cares?  So what if you can make a bar of unbinilium that lasts longer than the Sun?  The reason to care is that we have no idea what kind of fantastic material properties compounds of these new elements could have.  Take for example the so-called “noble gases”; they are in the column on the far right of the table, things like neon and argon.  For a long time, they were thought to be completely inert (the term noble gas comes from the idea that they were too aloof to hang out with the other elements) and didn’t form compounds with anything.  However, thanks to the relentless process of science, compounds involving them were form and are very useful.  Xenic acid, for instance, is a dissolved compound of the noble gas xenon that is a fantastic oxidizing agent (essentially, a very powerful cleaner and disinfectant).  It has the benefit that, when it reacts with material, it doesn’t contaminate the sample since xenon itself is non-reactive.  This makes it ideal for situations like creating high-end electronics where contamination would ruin the device.

If we could synthesize compounds of new super-heavy elements, we may be able to create new super-strong materials to build with, new materials for medical imaging and research, new fuels to use in the reactors of the future.  New types of material for the next generation of permanent magnets to power electric vehicles.  We really have no idea.  No one could have predicted how the discovery of the properties of silicon change humanity, who’s to say there isn’t a better, more amazing version of silicon out there? (Maybe 117, since it is in a position to be a semi-metal, like silicon…)  Who knows!

That’s why discovering element 115 is important, because discovering new things and learning how to harness them (for better or worse) is what we humans do.  Plus, it’s just awesome…