Saturday, November 19, 12022 HE
- How Crazy is Dihydrogen Monoxide?
- What Makes Water Weird
- A Plethora of Peculiar Properties
- Water Politics
Hopefully, the DHMO parody above did not mislead you too far. My apologies if it did. I first encountered the hazards of water meme in Bill Bryson‘s book, A Short History of Nearly Everything, where he references the challenges of living in a world dominated by “dihydrogen oxide.” Since then, I’ve always found the misinformation/disinformation water parody amusing. It cuts to the core of the limits of our scientific literacy and plays on the paradox of our present epistemology-ontology duality. We live at a time when the extent of human knowledge is so enormous that it easily surpasses the extent required for existence. You need not know the molecular makeup of dihydrogen monoxide to get by in your day-to-day life. Nor many of the other scientific curiosities our neo-cortex curates. As the parody suggests, we live under the illusion that we understand the world around us, yet many of us cannot change our sparkplugs or explain how a toaster works. The so-called illusion of understanding is one of our many formidable cognitive biases. While I am not suggesting that everyone needs to be able to explain the intricacies behind bread broiling, I would suggest that there is a base level of epistemic responsibility that we all have. If you are going to believe something, you need to have justification for your belief. Or, in the context of our technological world, an underlying understanding of the utilities with near universality. In the case of the water parody, that responsibility consists of having a critical mind to contend with the confusing content. The economic journalist Tim Harford warns us to be wary when presented with information that evokes an emotional response. We are more susceptible to misinformation when we are emotionally engaged. Emotional thoughts seem to override rational ones. If while reading through the parody your instinct was to ban DHMO for the apparent threat that it poses, I hope you can use the parody as an example of why we need to have justification for our beliefs.
I am a proponent of extending the concept of literacy to all aspects of life. I see scientific literacy under a more general and historical view of “science” as scientia, that is knowledge. To me, a healthy society is one in which all peoples are proficiently literate across a spectrum of endeavours. We should all strive to be proficiently literate in reading/writing, information/digital media, science, health, culture, finance, and law to enable individual achievement for collective success.
How Crazy is Dihydrogen Monoxide?
I thought I would use the water parody as the prelude to this post to pay tribute to some of the weird, yet miraculous properties of water since it is the medium of stand up paddleboarding (SUP). Without water and its strange properties, none of us are here to bear witness to the awesomeness of it all. And I couldn’t resist tossing in a minor commentary on misinformation and epistemic responsibility, given the global state of affairs. I am astounded every day that in 12022 HE, we as a collective can be simultaneously so smart and yet so stupid. Science denialism is not a new phenomenon, but the fact that it is still prevalent and perhaps on the rise is an alarming trend at a time when access to information should be easy. For great advice on how to confront five psychological challenges that can lead to science denialism, see here. And now, without further ado, welcome to the world of water’s wackiness.
Water is weird. At face value, it seems like a simple thing. Again we are under the illusion that we know more than we do. Water is so ubiquitous that we often fail to realize just how strange a compound it actually is. Apart from molecular oxygen (O2), “oh-two,” I’m hardpressed to come up with another substance whose chemical formula has entered the popular vernacular, “aitch-two-oh” (H2O). Over 70% of the Earth‘s surface is covered by water, and approximately 60% of the human body by weight is water. Water is all around and within us. So it is easy to miss just how strange a substance it is. But we are mistaken in assuming the ability to recite the chemical composition of water means we have a deeper understanding of its chemical properties. When you dive into it (sorry couldn’t resist the pun), water does some wacky stuff. We will start with what water does at different temperatures. But first, a quick chemistry review.
A Quick Chemistry Review
Chemistry is the study of the composition, structure, properties, and change of matter. Matter, for that matter, is classically defined as anything that has rest mass and volume (i.e., it takes up space) and is made up of subatomic particles. Where things get madder is at the quantum scale. Our current understanding of matter is that the apparently substantial stuff is actually no more than fluctuations in the quantum vacuum. Simply put, everything as we know it boils down to energy fluctuations in fields. If that leaves you confused, perhaps this explanation by Kurzgesagt can give you a little more of a sense of “What is Something?“
At a more practical level, chemistry is chiefly concerned with atoms, a basic unit in chemistry, and their interactions with other atoms. Chemical elements, or elements, are any substances that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are groups of the same atoms. Atomically, elements are the fundamental material of which all matter is composed. Two or more atoms form the smallest identifiable unit into which a pure substance can be divided, a molecule. Molecules can either be made up of the same element (or atoms) or two or more elements. For example, the chemical oxygen (O) is an element that can make up the molecular form most common on Earth, molecular oxygen or dioxygen (i.e., O2). What is confusing is that we are generally referencing dioxygen in common parlance when we talk about the abundant atmospheric gas we breathe. Any substance comprised of two or more chemical elements is a chemical compound. Water is thus a chemical compound comprised of two hydrogen (H) atoms for every oxygen atom (i.e., H2O).
What is Water?
Water is a polar inorganic compound. At room temperature, it is a tasteless and odorless liquid, nearly colorless with a hint of blue. Water is the only common substance to exist as a solid, liquid, or gas under normal terrestrial conditions.
Water is vital for all known lifeforms, despite providing neither food, energy, nor organic micronutrients. Recent research in biochemistry suggests that water surrounds protein structures and acts as a sort of scaffolding to facilitate molecular binding and enzymatic reactions and acts as an electrical conduit forming water wires to pass charges along hydrogen highways. Its chemical formula, H2O, indicates that each molecule contains one oxygen and two hydrogen atoms, connected by covalent bonds. Covalent bonds are a type of chemical bond that involve the sharing of electrons to form electron pairs between atoms. The hydrogen atoms are attached to the oxygen atom at an angle of 104.5°, giving it a tetrahedral structure. The tetrahedral structure arises because all the electron pairs, shared and unshared, repel each other. The most stable arrangement is the one that puts all electron pairs farthest apart from each other: a tetrahedron. The lone pairs are slightly more repulsive than the bonded electrons, so the angle between the O−H bonds is slightly less than the 109° of a perfect tetrahedron, around 104.5°.
What Makes Water Weird
Water’s Boiling and Freezing Point
Q: Why is most of Earth’s water liquid?
A simple definition of the boiling point is the temperature at which a liquid boils and turns to a vapor. More accurately stated, the boiling point of a substance is the temperature at which the vapor pressure of the liquid equals the pressure surrounding the liquid and changes into a vapor. Whereas, the freezing point, is the temperature at which a liquid becomes a solid. Water is a hydride of oxygen since an oxygen atom is covalently bound to hydrogen. Compared to other hydrides, water has a really high boiling point and a really low freezing point. The boiling points of hydrides should trend with the molecule size (increasing boiling points with increasing molecule size or vice versa). Looking at the periodic table in the Group 16 elements (i.e., the same column as oxygen, also called the chalcogens) you can locate tellurium (atomic number, Z = 52). The chalcogens elements all have six valence electrons, leaving them two electrons short of a full outer shell.
Tellurium (Z = 52) is larger and heavier than oxygen (Z = 8) and should have a higher boiling point based on its molecular size. The same holds for selenium (Z = 34) and sulfur (Z = 16). As the table below demonstrates, the boiling points for the hydrides follow the size rule. The boiling points for hydrogen telluride (H2Te), hydrogen selenide (H2Se), and hydrogen sulfide (H2S) decrease with decreasing size (-2, -41.25, and -60 °C, respectively). Following the trend, you would expect an even lower boiling point for water. But as most people know, the boiling point for water at sea level is 100 °C! So despite water’s small molecular weight, water has an incredibly big boiling point. And the reverse holds for the freezing (or melting) point, in that water freezes at a much higher (warmer) temperature (0 °C) than its hydride kin. The main reason for this is hydrogens bonds. And as we will see, hydrogen bonds are essentially the reason for all of the water’s weirdness.
|COMPOUND||BOILING POINT||FREEZING POINT|
|Hydrogen Telluride (H2Te)||-2 °C||-49 °C|
|Hydrogen Selenide (H2Se)||-41.25 °C||-65.73 °C|
|Hydrogen Sulfide (H2S)||-60 °C||-85.5 °C|
|Water (H2O)||100 °C||0 °C|
Hydrogen bonds are an attractive intermolecular force (more on this below). In water, hydrogen bonds hold individual molecules together, and breaking them requires energy. The additional energy required to overcome the hydrogen bonds in water gives water its higher boiling point. Conversely, water has a lower freezing point (i.e., phase changing into a solid) because of the attraction of hydrogen bonds. The boiling points of hydrides are also affected by the weaker intermolecular van der Waal forces. The van der Waal forces are “weak, short-range electrostatic attractive forces between uncharged molecules, arising from the interaction of permanent or transient electric dipole moments” (Oxford English Dictionary). The van der Waal forces account for the higher boiling point for the larger hydride molecules since they have more valence electrons, and thus a high probability of instantaneous electron sphere imbalances and ultimately greater van der Waal forces. For comparison, hydrogen bonds in water (approximately 23 kJ·mol-1) are nearly six times stronger than the strongest of the weaker intermolecular van der Waal forces (typically ranging from 0.4 kJ·mol-1 to 4 kJ·mol-1).
A: Due to water’s hydrogen bonds, it has an exceptionally high boiling and low freezing point. Because the average temperature on Earth is 14 °C most of Earth’s water (~97%) is found in liquid form in the oceans.
As mentioned briefly above, hydrogen bonds are attractive intermolecular forces. Britannica defines hydrogen bonds as an “interaction involving a hydrogen atom located between a pair of other atoms having a high affinity for electrons.” They are primarily electrostatic forces between a hydrogen atom that is covalently bound to a more electronegative atom, typically nitrogen (N), oxygen (O), or fluorine (F). In this sense, hydrogen bonds are not true bonds like covalent or ionic bonds. These elements are the most electronegative (more on electronegativity below). It is the difference in electronegativity values (χ) between hydrogen (χ = 2.20) and oxygen (χ = 3.44) that gives water its chemical polarity (more on polarity below). Because oxygen is more electronegative, it pulls the electron pairs slightly closer, making it more negative. The hydrogen atoms are slightly further away from their shared electrons, so they are slightly more positive. Since opposites attract, the more positive oxygens attract more to the more negative hydrogens. These interactions are fleeting and fluctuating but cumulatively keep the molecules closer together. A simple way to think of the hydrogen bonds in water is that they make the substance sticky. Individual molecules hold on to one another so that water remains in a liquid state across a wide range of Earth’s temperatures. Without the hydrogen bonds, water would be a gas at terrestrial temperatures like its hydride counterparts.
(1) – Hydrogen bonds between molecules of water
Electronegativity: Electron Tug-of-War
Electronegativity is the tendency for an atom to attract shared electrons when forming a chemical bond. The periodic table below demonstrates the electronegativity of the elements. You can see that the general trend is that electronegativity increases as you move from left to right across a period and decreases as you move down a group. Thus, the most electronegative elements (our usual suspects of nitrogen, oxygen, and fluorine show up again) are found on the top right of the periodic table. While the least electronegative elements are on the bottom left. This trend is because an atom’s electronegativity is affected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus. The higher the electronegativity, the more an atom attracts electrons. Electronegativity serves as a simple way to quantitatively estimate the bond energy and the sign and magnitude of a bond’s chemical polarity. The term electropositivity is loosely defined but is essentially the opposite of electronegativity. Electropositivity characterizes an element’s tendency to donate valence electrons. As we saw above in water, the greater electronegativity of oxygen (χ = 3.44) compared to hydrogen (χ = 2.20) means oxygen hogs the electrons creating a dipole and making oxygen a polar molecule.
Polarity: A Little More Chemistry
Molecules can be divided into two classes, polar and non-polar. Polar molecules form when there is a difference between the electronegativity values of the atoms participating in a bond. The difference in electronegativity creates a dipole within the molecule or an unequal sharing. One atom is more electronegative and will attract the electrons of the more electropositive atom. In the case of water, oxygen pulls the electrons toward its centre, becoming more electronegative. Whereas, hydrogen loses hold of its electron and becomes more electropositive. The result is a polar covalent bond between the atoms, and they share their electrons, albeit unevenly. Typically, a polar covalent bond will form if the electronegativity difference between the two atoms is between 0.5 and 2.0. If the electronegativity difference between the atoms is greater than 2.0, the bond is ionic. Thus, ionic compounds are technically extremely polar molecules. However, most of the time, when a molecule is labelled as “polar,” it means it has a polar covalent bond specifically. Not that it is generally polar, since that would include ionic compounds, which are typically specifically referenced as ionic bonds.
A Plethora of Peculiar Properties
Water is often referred to as a “universal solvent.” But we must take this claim with a grain of salt (pun intended, and joke stolen). Water cannot dissolve everything. But because water is a polar molecule, it is capable of dissolving more substances than any other liquid. For this reason, it is often called the “universal solvent.” The polarity of water means it can become attracted to many other different types of molecules. These are the properties of adhesion and cohesion. Water can be so heavily attracted to a compound, for example, salt (sodium chloride, NaCl), that it can disrupt the attractive forces that hold it together. Essentially, the polarity and hydrogen bonds of water are strong enough to overpower the ionic bonds of the sodium (Na+) and chloride (Cl–) ions in the salt compound and dissolve it. The negative charges of the oxygen molecules are attracted to the positive charges of the sodium ions. While the positive charges of hydrogen molecules are attracted to the negative charges of the chloride ions. Effectively, the sodium and chloride ions are walled off from each other by a molecular barrier of water (see the bottom of the schematic below).
The importance of water as a near-universal solvent cannot be understated. Every living thing on Earth depends on this property. It means that wherever water goes, either through the air, the ground, or through our bodies, it takes along valuable chemicals, minerals, and nutrients.
Slippery and Sticky
Q: Why can you wet your fingers to make them sticky to open a plastic garbage bag but that you put water on a plastic water slide to make it slippery?
It seems water can have the opposite effect under similar circumstances, i.e., the interaction between skin and plastic. The best explanation I came across for this dichotomy was in the BBC‘s The Curious Cases of Rutherford & Fry two-part series on “The weirdness of water, Part 2 of 2“, which was the inspiration for this post. I listened to Parts 1 and 2 when they first aired in January of this year and then relistened to them before writing this post. In the case of the water slide, water acts as a lubricant because it is a liquid and can flow. The thin film of fluid between the skin and plastic surfaces allows the layers to move over one another with less friction. In the case of making your fingers sticky, this seems to be a phenomenon specific to that scale. The thin layer of water provides surface tension. Surface tension arises from cohesion and adhesion. In the thin layer of water between your skin and the plastic bag the molecules cohere with one another. Whereas, at the exterior interface, the water molecules adhere to the skin and plastic. This surface tension effect is only sufficient around the millimetre scale or less. At larger lengths, the forces involved surpass the adhesive and cohesive powers of water. For a fun foray into the fantastical fathoms of the effects of surface tension across different biological sizes, check out the video below by Kurzgesagt.
A: Water is both cohesive and adhesive, giving it surface tension. Over larger forces and lengths, these properties mean water acts as a lubricant. At smaller forces and distances, water acts like an abradant.
Walk on Water: The Jesus Effect
Q: What’s the heaviest animal that can walk on water?
Water striders? Fire ants? Water snails? Basilisk lizards? Many creatures come to mind. Perhaps some semantics are in order. If the question is specific to liquid water, then it needs to be a creature that cannot break the surface tension of water. All of the creatures mentioned fit that bill. But if water is in reference to the chemical compound regardless of the matter state, then the possibilities extend.
As mentioned, water is an outlier as a hydride for its boiling and freezing points. It is also an outlier when it freezes, in that water is less dense than when it thaws. Think about that for a moment. That is super strange! Water, in its solid state, ice, is denser than in its liquid state. Perhaps that doesn’t strike you as strange straight away since we see it so often. But when you stop to think of what a solid versus a liquid versus a gas means for the density of atoms, solid ice floating on water is a bit strange. I struggled to think of an everyday example to illustrate this but failed to fathom one. I settled on imagining a vat of melted butter with a solid stick of butter dropped into it, or volcanic rock floating on top of flowing lava. Those would be incredibly peculiar sightings in their own right, let alone the mindboggling physics that would need to be at play. Unless you are a chemist or physicist, I don’t think the matter state densities of most materials readily come to mind. So I think it is easier to do a thought experiment. When you consider that the material density difference between solids, liquids, and gases is due to the distance between the particles in the various states, it is easier to imagine which state will be heavier (i.e., denser). Particles in a solid are close together, slightly apart in a liquid, and further apart in a gas. The table below is a summary.
|State||Distance between particles||Density||Density in kg/m3|
|Solid||Very close together||High||Solid iron = 0.78|
|Liquid||Slightly further apart than a solid||Slightly less than a solid||Liquid iron = 0.69|
|Gas||Very much further apart than a solid or liquid||Very much less than a solid or liquid||Oxygen gas = 0.00014|
To be fair, water is not alone in being denser as a liquid than a solid. There are a few other materials that have this same property (e.g., mercury, silica, germanium, and bismuth). Any substance with a lower density will float on the denser material (or stated conversely the denser material sinks). This phenomenon is due to Archimedes’ principle. Archimedes’ principle explains why some wood (density ~700 kg/m3) and oil (~900 kg/m3) float on water (~1000 kg/m3) since they have a lower density. The approximate density values arise from variations in purity and temperature. Materials are typically denser at cooler temperatures since molecules move more slowly and are generally closer together. What makes water so special in comparison to the other solid versus liquid density oddities mentioned is its importance to life as we know it and its abundance on Earth. Approximately 71% of the Earth’s surface is covered with water, with an estimated 97% found in Earth’s oceans. The remaining roughly 3% is found in the air as water vapor, in rivers and lakes, in icecaps and glaciers, in the ground as soil moisture and in aquifers, and in us and the rest of the living world. The formation of ice in freshwater or saltwater (density ~1020-1050 kg/m3 depending on ocean depth) is essentially the same process but occurs at different temperatures. Freshwater is densest at 4 °C as per the graph below comparing the density against temperature. The inverted “U” shape of the plot creates a curious situation. For freshwater to freeze it must reach 0 °C or colder. Since the average global summer freshwater temperature ranges from 18 to 24° C, some freshwater will likely reach 4° C en route to the average winter temperature between 2 to 7° C. As the graph demonstrates, en route to its freezing point, the surface water of a freshwater lake, for example, will get denser and, therefore, sink. As the denser water sinks, it is protected from the cooling effects of the ambient air and thus cannot freeze. However, some of the water that remains at the surface cools to less than 4° C before sinking and therefore becomes less dense than the 4° C water density barrier below. The denser water barrier creates the condition for ice to form at the surface of freshwater bodies, enabling the possibility for current-day Canadian (and other cold climates) pond hockey, eh! Without this peculiarity of water, ice would sink and may have prevented the development/survival of life on Earth.
Why is ice less dense than water? You guessed, hydrogen bonds! As the temperature of water decreases, the lower kinetic energy means the molecules move less and get more densely packed. They are closest at 4° C. However, below this temperature, the hydrogen bonds of water molecules take hold and start to organize into a multilayered hexagonal lattice. The image below depicts how hydrogen bonds in the liquid water on the left constantly break and reform as the water molecules move past one another. In ice, on the right of the image, the hydrogen bonds have organized into an orderly hexagonal lattice. Each hexagon has a space at the centre. The empty space reduces the density of ice and allows ice to float on water.
The three-dimensional ice model below allows you to manipulate the structure in space to examine the lattice.
Source: Structure of ice by Justus Mutanen on Sketchfab
In saltwater, the same process occurs, albeit with a few complicating factors. First, salinity lowers the freezing point of water. For sea ice to form, the water must cool to approximately -2 °C. The effect of increased salinity on lowering the freezing point of water is the reason roads are salted in colder conditions. It prevents ice from forming. Despite the lower freezing point for ocean water, it is still freezable at earthly temperatures. Salinity also increases the density of water. This effect is part of the process behind thermohaline circulation. Saltier water sinks, leaving the surface water less salty, thus less dense, and more readily freezable at cold temperatures. During the formation of sea ice, relatively fresh water is added to the surface, contributing to the lower density and warmer freezing point. Thus, the same sub-surface density barrier that allowed the superficial layer of freshwater to freeze also exists in the formation of sea ice.
Not all ice is created equal. At the time of writing this post, there are 19 known forms of ice, with the 19th polymorph only recently discovered. This proven polymorphic plethora is not to be confused with the pseudoscientific ideas of the late Masaru Emoto, who claimed that human consciousness could affect the molecular structure of water. I came across Emoto’s ideas, as I am sure many others did too, in the 2004 film What the Bleep Do We Know!? The pseudoscientific film posits a spiritual connection between quantum physics and consciousness. And as one review I read wrote, “would be a riot if people didn’t take it so seriously.” That was the problem that my 23-year-old self had when I watched the film. From memory, the parts on behavioural neuroendocrinology were plausible and possibly even accurate (I haven’t rewatched the film to confirm my memory). But therein lies the pseudoscience. In some sense, pseudoscience is like a conspiracy theory, a few grains of truth scattered amongst falsities that are (deliberately) difficult to falsify. In What the Bleep Do We Know!?, for the average viewer, there was enough believable material to make the unbelievable possible. While I was skeptical about the ice claims then, my defensive skepticism was lowered by the more accurate claims around behavioural neurobiology. At the same time, the esoteric truth that ice actually has polymorphs is a factoid so arcane but yet possibly accessible to enough through a secondary school science lesson that it may exist in the recesses of the subconscious so that the similar claim of different ice forms created via human cognition is close enough to conflate. It is through this same phenomenon of familiarity that conspiracy theories often take hold. For example, take the central tenet behind the QAnon conspiracy theory. That a “cabal of Satanic, cannibalistic sexual abusers of children operating a global child sex trafficking ring conspired against former U.S. President Donald Trump during his term in office” seems preposterous at face value. Yet, taken in the context that this cultish clan of conspiracy theorists came into continuance around 12017HE, which coincides with the continued criminal case of convicted sex offender Jeffrey Epstein, who had various political affiliations, then it is not a complete foray into fantasy. Granted there are some fantastical leaps of reason and evidence that must be made to mix the two narratives, my point is that premise of pedophilic political affiliates is present. Pseudoscience relies on sprinkling in a little bit of real science or at least some sciencey-sounding stuff to get traction. And that is very evident in What the Bleep Do We Know!?
As a fun side note, in my searches for what is the heaviest animal that can walk on water, I came across a possible scientific explanation of how Jesus purportedly walked on water. Hence the title for this section. The researchers found that there may have been a cold snap around the time of Jesus, which may have frozen the Sea of Galilee, allowing Jesus to walk on water. I was brought up in a Roman Catholic tradition, but from an early age had trouble with some of the tenets of the faith. In my teens, I trended toward atheism and haven’t strayed in my beliefs since. In my youthful skepticism, I found myself questioning the reality of an all-powerful god, and by extension, the narrative of his only begotten son. I recall reading The Passover Plot by British biblical scholar Hugh J. Schonfield and coming away with the conception that Jesus was a historical figure. I was left thinking that while Jesus likely lived, the accounts of his life were either embellished or fabricated. I failed to ponder the possible but improbable peculiar paleolimnological phenomena playing a part. In any case, whether or not Jesus’ liquid density-defying dawdle occurred, he isn’t the heaviest animal to walk on water, though the mechanism might be the same. A more realistic response is below.
A: An elephant (if the water is frozen). And while not the heaviest, a stand up paddleboarder also walks on water to a degree.
The Hot Spin
Imagine a machine so magnificent that it can harness electromagnetic radiation to force the alignment of water molecules within a magnetic field, causing them to spin and vibrate. Therefore forcing them to friction and heat up. You could name such a device a “magnetron.” Or perhaps better, a “microwave” (oven).
Microwaves (electromagnetic radiation) have three characteristics that allow them to be used in cooking. Microwaves are reflected by metal, yet they can pass through glass, paper, plastic, and similar materials. And microwaves are absorbed by foods. In a microwave oven, microwaves are produced by an electron tube called a cavity magnetron. The microwaves are reflected within the metal interior of the oven, where they are absorbed by food. Microwave radiation creates an oscillating magnetic field. Since the electromagnetic field is constantly changing its orientation, polar molecules, like water, within the food spin rapidly. The polar molecules undergo dipole rotation as they try to maintain their orientation within the changing field. The dipole rotation produces heat that cooks the food. So, the next time you nuke something, consider just how fantastical your molecular H2O spinner is!
Water is Alien
Q: Where did all the Earth’s water come from?
There are two hypotheses regarding the origin of the Earth’s water. The more commonly accepted contention is that the Earth’s water is alien. During the Late Heavy Bombardment (approximately 4.1 to 3.8 billion years ago), countless meteors rained down on the Earth and the Moon delivering water via these icy asteroids and comets. An alternative hypothesis, gaining more credence recently, is that the Earth’s water came from within the Earth. Perhaps the reality lies somewhere in between with a mixture of water sources for the Earth. In any case, much as we are the product of stardust, so too are the ultimate origins of water. For a more in-depth account of the Earth’s water’s origins, check out this video, “Where Did Earth’s Water Come From?” from the History of the Earth YouTube channel. The channel is a fantastic series on the entire history of the Earth over geological time scales.
A: Ultimately, stardust. But the jury is out on whether it was a cosmic payload or a terrestrial bleed.
What’s Weird About 37 °C
Water has a higher specific heat capacity than land (over a four-fold difference). I discussed this in a past post, “Down with the Sound“, that covered the nuances of the wind patterns in the Átl’ḵa7tsem (Howe Sound). Heat capacity is the amount of heat needed to be supplied to an object to produce a unit change in its temperature. Specific heat capacity is essentially the same property scaled to mass. So for the same mass, it takes more energy to heat water. This same phenomenon means that water holds heat more readily than land. Relevant to SUP is that this property of water (again due to hydrogen bonds) accounts for many maritime weather effects. For the Átl’ḵa7tsem fjord system, this creates the strong squamish wind patterns observed.
Bringing this back to what’s weird about water and 37 °C is that this temperature is near the lowest heat capacity of water (see the graph below). In fact, it is closer to 40 °C, but that is pretty close. Thirty-seven degrees celsius is the average human body temperature. What makes this fascinating is that when heat capacity is at its lowest, the least amount of energy is required to change the temperature. Interestingly, this is near the body temperature of most mammals, which ranges between 36 and 40 °C. Now, to be fair, this is purely conjecture and could be coincidental. But it is a curiosity that those body temperature ranges would take advantage of this water property and be the most energy efficient for maintaining body temperature.
One more point on water’s heat capacity relates to warm ocean currents. The sun heats the Earth unevenly due to the amount of insolation received varying by location due to various factors like sun angle, air mass, day length, cloud coverage, and pollution levels. The differential heating effects are particularly evident between land and water masses. Since the oceans can store heat more readily (hydrogen bonds), the resulting thermohaline circulation currents are important for the redistribution of global heat. This ultimately affects our weather, climate, and possibly the Earth’s capacity to sustain life as we know it. Check out the video below for a succinct summary.
When Is Water Wet?
While we all have an experience of what wetness is, explaining what wetness is, is not so simple. An article by Farah Egby on Medium poses the question more eloquently, “Is wetness a property of water or a description of how we experience it?” But chalk one up for science, as this question has a formal answer. It seems the magic number is six for water molecules to behave as a liquid and manifest the emergent property of wetness. The phrase the whole is greater than the sum of the parts is generally attributed to Aristotle, though arguably a misquote. Regardless of the veracity/accuracy of the quote, I find the concept of emergence fascinating. And not just in the application to the wetness of water, but in systems theory broadly. Check out the video below for a fun foray into emergence from the folks at Kurzgesagt, who summarize emergence as rules to create order out of chaos.
And then, to cap off our voyage through the peculiarities of water, I thought I would finish with a political populations piece. A friend sent me the video below from Real Life Lore on how water, or more precisely precipitation patterns, play into the present population pattern of North America. I recall in university hearing warnings about a pending water crisis, a new blue gold, and future water wars. While I didn’t discount the possibility of future problems, at the time, I felt these facets were further removed. The video below, along with the present state of climate change, gives me an eery feeling that perhaps the water crisis is closer than we think.
And there you have it, some of the fun, fascinating, and frightening facts about water.