Would a Helicopter Work On Mars?

This is one of those questions that I wish I could remember the context for. But I don’t. It’s just sitting there in the master list of the questions my son has asked, sandwiched between “What’s plankton?” and “What if the oceans froze?”, and I have no idea when or why he asked me this. Just “would a helicopter work on Mars?”

Usually I try to jot down something about the context. But not this time.

So, let’s get to the question. Would a helicopter work on Mars?

The simple answer appears to be “yes”. The Jet Propulsion Laboratory, on January 22, 2015, put out a press release on that very subject. They’ve designed a small proof-of-concept drone with the imaginitive name Mars Helicopter. It’s a 2.2 pound (1 kg) device, cubical in shape, with a 3.6 foot (1.1 meter0 rotor span. As designed, it would be deployed to work in conjunction with a future Mars rover.

The helicopter would fly ahead of the rover almost every day, checking out various possible points of interest and helping engineers back on Earth plan the best driving route.

Scientists could also use the helicopter images to look for features for the rover to study in further detail. Another part of the helicopter’s job would be to check out the best places for the rover to collect key samples and rocks for a cache, which a next-generation rover could pick up later.

If you prefer visuals, JPL also has a video about Mars Helicopter. It’s primarily CGI, since they haven’t constructed a fully-functional model, but it includes a few shots of a prototype trying to fly in a simulated Martian atmosphere.

But, what would it take to make a helicopter work on Mars? Not that I don’t believe JPL when they say it can be done – they are literally rocket scientists, and their entire job revolves around building things for space and other planets – but I’m curious. Fortunatly, NASA has me covered again. Let’s turn now to a paper describing the actual experiments NASA has done on rotary-wing aircraft for Mars, titled Experimental Investigation and demonstration of Rotary-Wing Technologies for Flight in the Atmosphere of Mars.

The paper begins by describing the challenges faced in constructing a rotary-wing aircraft for the Red Planet:

The Martian atmosphere is 95% CO2 with the remaining 5% comprised of N2 and other trace gases. Mars’ gravity is slightly greater than a third of Earth’s. The atmosphere of Mars is extremely cold and thin (approximately 1/100’th of Earth’s sea-level atmospheric density). Further, a seasonal variation of approximately 20% of the planetary atmospheric mass occurs on Mars (a consequence of polar CO2 condensation and sublimation). Given the thin, carbon-dioxide-based Martian atmosphere, developing a rotorcraft design that can fly in that planetary environment will be very challenging.

After that, the article goes into a lot of cool descriptions of various hypothetical rotorcraft designs and a whole lot of math that flies right over my head. It’s all stuff I’d love to understand, but it gets into some advanced-looking physics and aviation engineering concepts that I’ve never studied. Here’s what I could pick out:

* NASA is investigating both coaxial and quad-rotor configurations.
* Experiments have been done with battery power, electricity generated by fuel cells, and engines fueled by hydrazine. At present, some variety of electrical power seems to be the best option.
* It’s really hard to test an actual prototype under conditions that replicate Martian gravity, atmosphere pressure, and composition. At present, we’ve only managed it with the pressure.
* The rotors will have to be really big and spin really fast, and the rotorcraft will have to be really light.

A reasonable layman’s description of what a Martian helicopter can be found in this quote from the second page of the paper:

From an aeromechanics perspective, Mars rotorcraft will be very different from their terrestrial counterparts. Mars rotorcraft will have very large lifting-surfaces and will be required to have ultra-lightweight construction. For example, in order to lift ten kilograms of vehicle mass on Mars, a single main rotor (at a disk loading of 4 N/m2) would have to have a radius of approximately 1.7 meters.

For added fun, check out Interplanetary Cessna on Russel Monroe’s What If? site, which answers the question “What would happen if you tried to fly a normal Earth airplane above different Solar System bodies?” It’s not specifically on the topic, but it’s close.

Why Are They Called “Numbers”?

I live in a condominium, one of those ones that look like an apartment building. It’s not a bad building, really, but it has a couple of interesting quirks. Like the locked storage closet in a hallway by the stairs. But we’ve adapted, and we now use it to store things that we don’t want to have to walk out to the garage for, but we also don’t want to keep in the house. Like our Christmas decorations, and my tools.

Well, my son and I needed to fetch those tools – he’s got a white board now, and I promised him we’d hang it up on his wall. As I’m opening up the closet, he’s eagerly reading the brass numbers on each of the closet doors. “One,” he says. “Two. That’s our number! Three. Four. Why are they numbers?”

“What?” I ask, pulling my head out of the closet.

“Why are they numbers?”

I shrug. “Because we need to show which condo owns which closet, and…”

“No, daddy,” he corrects me. “Why are they called numbers?”

Oh, good. An etymology question. But fortunately, I’ve got the Online Etymology Dictionary to turn to for that. And they provide derivations for “number” as both a noun and a verb. As a verb, “number” comes from the Old French word nombrer, meaning “to count, reckon”. The “to assign a number to” meaning appears to date to the late 14th century CE, while “to ascertain the number of” appears to date to the early 15th century CE.

The noun form of “number” comes from the Old French nombre, which I strongly suspect is related to the Old French nombrer discussed above – I don’t speak French, though, so I really can’t prove it. Nombre comes from the Latin word numerus (meaning “a number, quantity”), which derives from the Proto-Indo-European (PIE) root word *nem- (meaning, “to divide, distribute, allot).

Because I was on the subject, I decided to look into the origin of the words we use for the numbers themselves. It turns out that, at least for the first ten numbers, English number names appear to derive directly from PIE words, through Old Germanic and into English.

  • One derives from the Old English an, which derives from the Proto-Germanic *ainaz, which derives from the PIE *oi-no- (meaning “one, unique”).
  • Two derives from the Old English twa (which is the feminine and neuter form of the Old English twegen which also meant “two”), which derives from the Proto-Germanic *twa, which derives from the PIE *duwo.
  • Three derives from the Old English þreo (the feminine and neuter form; the masculine was þri or þrie), which derives from the Proto-Germanic *thrijiz, which derives from the PIE *trei.
  • Four derives from the Old English feower, which derives from the Proto-Germanic *fedwor-, which derives from the PIE *kwetwer-. The dictionary also notes that “the phonetic evolution of the Germanic forms has not been fully explained”.
  • Five derives from the Old English fif, which derives from the Proto-Germanic *fimfe, which derives from the PIE *penkwe-.
  • Six derives from the Old English siex (or six, or sex), which derives from the Proto-Germanic *sekhs, which derives from the PIE *s(w)eks.
  • Seven derives from the Old English seofon, which derives from the Proto-Germanic *sebun, which derives from the PIE *septm.
  • Eight derives from the Old English eahta (or æhta), which derives from the Proto-Germanic *akhto, which derives from the PIE *okto(u).
  • Nine derives from the Old English nigen, which derives from the Proto-Germanic *niwun, which derives from the PIE newn.
  • Ten derives from the Old English ten (or tien), which derives from the Proto-Germanic *tehun, which derives from the PIE *dekm.

So, why are numbers called numbers? Because the early Proto-Indo-European speakers decided to use the word *nem- when they were dividing things up.

Ice And Snow

It’s winter, and it finally snowed in these parts, and these two facts have combined to make my son quite happy. Every day after I pick him up from his preschool, he asks if we can go walk in the snow – something that turns into us hiking across snow-covered fields and throwing snowballs at each other, and which ends with us having to leave snow-caked shoes in the hallway and hanging snow-covered coats and gloves (and sometimes pants) in the bathroom to dry.

“Why does it snow?” he asked yesterday, after we were back inside and bundled up under some lovely fleece blankets.

Uhm… I haven’t the slightest idea. I mean, I know it must be related to the concept of rain. Both rain and snow are precipitation, after all. But I don’t really know why snowflakes form instead of, say, sleet. Which makes this a great question! And a great question to combine with another one he asked, which came up while he was drinking some water: “why is ice made out of water?”

So let’s find out.

What is “Freezing”?

To understand freezing, we’ll need to take a quick look at matter. For help with this, we’ll turn to LiveScience.com and Matter: Definition & the Five States of Matter. They define matter as “anything that has mass and takes up space). The state of matter is the form the matter takes, with the most common states being solids, liquids, gasses, and plasma. (The article lists Bose-Einstein condensate as the fifth state; Wikipedia lists twenty-one different states). Matter can also be said to be in a phase, which is “a region of space (a thermodynamic system) throughout which all physical properties of a material are essentially uniform”.

Using ice as an example, an ice cube is water in the solid state in a phase the size of the cube. Ice cubes in a glass of water then represent a system which has water in two states (solid and liquid) and two phases (the liquid volume, and the volume of the ice cubes).

With that in mind, we’ll turn to Purdue University and Freezing:

When a liquid is cooled, the average energy of the molecules decreases.

At some point, the amount of heat removed is great enough that the attractive forces between molecules draw the molecules close together, and the liquid freezes to a solid.

The temperature of a freezing liquid remains constant, even when more heat is removed.

The freezing point of a liquid or the melting point of a solid is the temperature at which the solid and liquid phases are in equilibrium.

The rate of freezing of the liquid is equal to the rate of melting of the solid and the quantities of solid and liquid remain constant.

What happens when water freezes?

When water freezes, it undergoes a phase change from liquid to solid. Energy is removed from the water molecules, slowing them down and making them become more dense. However, it hits maximum density at 4 degrees Celsius (39.2 degrees Fahrenheit) – below that temperature, water starts getting less dense.

Why?

As water begins to freeze, the molecules crystallize into open hexagonal structures.
waterhex
This hexagonal structure contains more space than liquid water, making it less dense. So, by the time it has fully hardened into a solid, it floats on top of the liquid water.

How do snowflakes form?

Snowflakes start off just like rain – as water droplets forming around pollen or dust. The distinctive shapes arise because of crystalline hexagonal structure I mentioned above. A single water crystal will have six sides, and this causes the crystals to build up into a symmetrical pattern as they grow in size. The specifics of the shape are determined by the temperature and the atmospheric conditions:

Ultimately, it is the temperature at which a crystal forms — and to a lesser extent the humidity of the air — that determines the basic shape of the ice crystal. Thus, we see long needle-like crystals at 23 degrees F and very flat plate-like crystals at 5 degrees F.

The intricate shape of a single arm of the snowflake is determined by the atmospheric conditions experienced by entire ice crystal as it falls. A crystal might begin to grow arms in one manner, and then minutes or even seconds later, slight changes in the surrounding temperature or humidity causes the crystal to grow in another way. Although the six-sided shape is always maintained, the ice crystal (and its six arms) may branch off in new directions. Because each arm experiences the same atmospheric conditions, the arms look identical.

Sleet, Hail, and Frozen Rain

All of this made me wonder, though. If snow is literally created by the same process that creates rain, where to the other types of “winter weather” come from? That is, sleet, and hail, and frozen rain. Fortunately, NOAA has the answer.

Snow generally begins life in the “dendritic growth zone” (aka the “snow growth zone”), a layer in the atmosphere with temperatures between 10.4 and 0.4 degrees Fahrenheit (-12 to 18 degrees Celsius), and cannot form if the atmospheric temperature rises above 32 degrees Fahrenheit (0 degrees Celsius). Additionally, the relative humidity of the atmosphere must be at 70% or greater. Note, however, that the dendritic growth zone is not a formal layer of the atmosphere (hence the term “zone” instead of “layer”) – it can form at different altitudes, depending on the weather.

At some point – one which is determined by the size of the snowflake and the weather conditions – the snowflake falls. It may partially melt as it falls, but as long as it passes through no more than “a very shallow melting layer” (no more than 1,500 feet thick) that is no more than 33.8 degrees Fahrenheit (1 degree Celsius) and then refreezes. In fact, partially melted and refrozen snowflakes help produce the wet snow that is so beloved of people who build snowmen and pack snowballs.

Sleet starts life as snow, and goes through a similar process to the creation of wet snow. However, it hits a melting layer that is less than 2,000 feet thick and has a temperature between 33.8 and 37.4 degrees Fahrenheit (1 to 3 degrees Celsius). All of which is a fancy way of saying that sleet is partially melted snow.

Freezing rain also starts life as snow. However, it hits a melting layer with a temperature above 37.4 degrees Fahrenheit (3 degrees Celsius). This makes it melt completely. The exterior cools below freezing as it falls, but it doesn’t fall long enough to turn into sleet before it hits the surface. But, since the exterior is at the freezing point of water (or extremely close), it freezes on contact with the surface.

Hail is as unrelated to snow as anything that starts out life as “ice crystals in the upper atmosphere” can be. It israin that gets blown up into extremely cold layers of the atmosphere and freezes. Then it falls when the wind won’t hold it up, only to (possibly) get blown upwards again and have more layers of ice freze around it. This can continue until the updrafts that keep throwing it upwards are no longer able to do so.

Where Do They Grow Bananas?

My son loves bananas. I can’t say I blame him. They taste good, they’re colorful, they have a distinct shape (none of this round business, like so many other fruits), and they have a convenient and easily removed peel. What’s not to love?

So he’s sitting on the couch eating a banana, because daddy is being bad and letting him eat in the living room. He contemplates the half a banana he’s got left, then looks at me and asks “where do they grow bananas?”

I shrug. “Uhm… Central Ameria, I think.”

“I think they grow in California!”

I look at him. “Really? Why do you think that?”

“Because they do!”

Five-year-old logic, ladies and gentlemen. But, it’s a good question. And so we’re off to the internet to research.

What is a banana?

This is a banana.
Banana3

So is this.
Red-Banana

And this.
wildbanana

Strictly speaking, bananas are berries. And no, I didn’t know that either. But a berry is defined as “a fleshy fruit without a stone produced from a single flower containing one ovary”. They are part of the Plantae kingdom (meaning they are plants), are angiosperms (meaning they are flowering plants) and monocotyledons (meaning their seeds contain only one embryonic leaf). They fall with in the order Zingiberales and genus Musa, a genus which contains about 70 species of bananas and plantains, and are considered herbaceous flowering plants (meaning they hae no persistent woody stem above ground).

Most likely, you are familiar with the Cavendish group banana, which is generally the cultivar you find in the fruit section of your local grocery store. These are seedless banana, in the sense that they do not form mature seeds. The little black dots in the center are immature seeds, but those seeds do not develop in the Cavendish cultivars. Instead, new plants are grown from transplanted rhizomes – little buds from the primary root, that can grow into new plants.

Note that the Cavendish is unusual in this regard. Many bananas, particularly wild ones, have seeds (as seen in this image from the University of Hawaii):
slicedbanana

Where are they grown?

There’s a great little article called Banana Market, available from the University of Florida’s EDIS site, that examines banana production. The Food and Agriculture Organization of the United Nations has also produced an Overview of World Banana Production and Trade that independently supports the information in the article. World production of bananas hit 97.3 million metric tons (mmt) in 2009, with 61% of those bananas being grown in India, the Philippines, China, Ecuador, and Brazil.

LyraEDISServletWorld’s top producers of fresh bananas

The united States accounts for approximately 0.01% of world banana production, with Hawaii producing the majority of those bananas.

Interestingly, only about 15.3% of the global banana production is exported. The remainder of the banana crops are used within the country that produced them. Ecuador exports 38% of that total volume, Colombia 13.2%, the Philippines 11.7%, Costa Rica 11.5%, and Guatemala 9.9%. 33% of those bananas are imported by the United States, almost as much as the EU and Japan combined.

Globally, the Cavendish banana accounts for 47% of all bananas cultivated. India alone grows 19% of all the Cavendish bananas, followed by Ecuador (12%) and then China (10%).

Are they grown in California?

The answer to that, as far as I can find, is yes. However, I couldn’t find any specifics on production quantities. I’m assuming that, given Hawaii’s dominance in U.S. banana production, the amounts are negligible.

How Do Mirrors Work?

My son loves mirrors. Not to the point that he spends hours in front of the mirror, mind, but he finds them interesting. He also thinks they work because of electricity, because both my car and my wife’s car are OnStar capable and so have a thick cable that connects the rear view mirror to the roof of the car. I haven’t been able to disabuse him of this notion, because he insists that I’m wrong when I tell him that electricity has nothing to do with reflection.

To tell the truth, I’ve been looking forward to this one myself. A lot. Because mirrors fascinate me, too. I’ve spent a lot of time in front of them, craning my head and discovering that I can see things in them that I wouldn’t have expected to be able to see reflected. You know, like how you can see into the living room a little by craning your head as you look into the bathroom mirror. They seem spooky at times, even though I know there must be a rational explanation.

Really, there is. It starts with the mechanics of how we see, and ends with physics.

How We See

Sight is a staggeringly complex concept that we generally take for granted. The National Eye Institute, part of the National Institutes of Health, provides a basic primer on how we see:

Light passes through the cornea, the clear, dome-shaped surface that covers the front of the eye. The cornea bends – or refracts – this incoming light. The iris, the colored part of the eye, regulates the size of the pupil, the opening that controls the amount of light that enters the eye. Behind the pupil is the lens, a clear part of the eye that further focuses light, or an image, onto the retina. The retina is a thin, delicate, photosensitive tissue that contains the special “photoreceptor” cells that convert light into electrical signals. These electrical signals are processed further, and then travel from the retina of the eye to the brain through the optic nerve, a bundle of about one million nerve fibers. We “see” with our brains; our eyes collect visual information and begin this complex process.

eyediagram

That light has to come from somewhere, of course. While there can be many different sources of the light our eyes uses, those sources are ultimately one of two different categories: luminous objects, or illuminated objects. Luminous objects generate their own light, like a lightbulb or the sun. Illuminated objects are objects that reflect light, like the moon. Or mirrors. Or, really, anything at all that you can see.

robotoverhorizon.jpg.560x0_q80_crop-smart

Pictured:  luminous and illuminated objects

What is reflection?

Dictionary.com provides the following definition of reflection:

Physics, Optics.

  • the return of light, heat, sound, etc., after striking a surface.
  • something so reflected, as heat or especially light.

It’s a little more complicated than that, but overly complicated. Reflection depends on something called the law of reflection, which states that “when light falls upon a plane surface it is so reflected that the angle of reflection is equal to the angle of incidence and that the incident ray, reflected ray, and normal ray all lie in the plane of incidence”.

Clear? If not, the University of Texas has you covered. Start with this image:

img1298

There’s geometry there, and if you’re like me you haven’t done any geometry since high school. But really, the concept isn’t difficult. The incident ray is the ray (light, in this case) that strikes the reflecting surface. Assuming the surface is smooth, the reflected ray bounces off at the same angle as the incident ray.

And if the surface isn’t flat?

Well, in that case, the law still holds. Imagine zooming in on a rough surface – a rough-cut block of wood, for instance. At a small enough level, there are flat surfaces. Each flat surface becomes the plane for this law, and then the light is reflected accordingly. The rougher the surface, the more chaotic the reflected rays. The smoother the surface, the more uniform the reflected rays. This is the key to the two types of reflection:

Print

Specular reflection is simply reflection from a surface that makes the majority of the incident rays travelling in the same direction reflect from the surface in the same direction. Diffuese reflection, on the other hand, is when the reflected rays scatter in different directions. Now, clearly, no surface is perfectly reflective. But mirrors produce significantly more specular reflection than diffuse reflection.

So why do things look reversed in a mirror?

It turns out that this is nice and simple. HowStuffWorks: Science explains this pretty well, but I’ll take a stab at it myself. In essence, it has to do with the fact that the mirror is just reflecting back light that reflects off an object. The light doesn’t flip around, so you see the right side of a reflected object (your body, for instance) on the left side of the mirror.

Hmm… still not clear. Here’s what HowStuffWorks said to help clarify it further:

Take a piece of thin, translucent paper and write your name on it. Stand in front of a mirror and hold the paper up so that you can read the paper normally. Now look in the mirror. You are seeing the back of the translucent sheet in the mirror, and the word is not reversed — it looks completely normal. Now turn the paper over and look at it in the mirror. It is reversed, but so are the letters on the back of the translucent sheet. Note that you turned the paper over — you reversed it!

Explained that way, it makes perfect sense. To me, anyway.

But what about the witchcraft?

Have you ever noticed that you can see things in mirrors that look like they are way, way off to the side?  Things that look like they shouldn’t be able to be seen?  This always felt like witchcraft to me.  I mean, I’ve always felt that there had to be an explanation that wasn’t black magic, but I didn’t know what it was.  Well, it turns out to be all about lines of sight and the law of reflection. If you’re standing to one side of the mirror, you see the reflected rays that have a flatter angle of reflection. Those reflected rays are created by incident rays that have a flatter approach angle relative to the plane of the mirror. But then your line of sight “in” the mirror is a line that follows the reflected rays “through” the mirror, making it appear that the reflected ray originated from an object inside the mirror.

All in all, it’s no wonder my son is fascinated by mirrors. They just don’t do what you think they’ll do. Instead, they do what physics thinks they’ll do, and that is usually a completely different experience.

What’s A Whirlpool?

It’s bath night for my son, and we’re nearly finished. The last step is our ritual of unstopping the drain and letting him play until all of the water runs out. This is generally a time of frantic activity as he tries to pack in as much play as possible. This night, he really pays attention to the way that his toys are caught by the current and begin spinning above the drain. He grabs one, pulls it away, and watches as it drifts back and starts spinning again.

“It’s like a whirlpool,” I observe.

“Yeah!” he agrees. And then, without missing a beat, adds “What’s a whirlpool?”

Uhm… uh… You know, I don’t actually know what a whirlpool is. Not really. Oh, sure I know what they look like – I have, ever since I watched 20,000 Leagues Under the Sea. But I don’t actually know what they are. All I can say is that I’m pretty sure they’re not places where water is draining out of the ocean through cracks in the sea floor.

Pretty sure.

Wikipedia defines a whirlpool as “a body of swirling water produced by the meeting of opposing currents”. The article goes on to note that powerful whirlpools are often known as maelstroms, and that any whirlpool with a downdraft is properly known as a vortex. Also, “the most powerful whirlpools are created in narrow, shallow straits with fast flowing water.”

The Times of India provides a paragraph-long explanation that, while generally agreeing, goes into more detail:

A whiirlpool is a large, swirling body of water produced by ocean tides. When flowing water hits any kind of barrier, it twists away and spins around rapidly with great force. This creates a whirlpool. Whirlpools can occur in a small area where a piece of land juts out into a river, causing the water to swirl around. They can also occur in the middle of the ocean when one current meets an opposing current, as when an incoming tide hits the ebb current of the last tide. Strong winds can also whip up the water into whirlpools.

Basically – for whatever value ‘basically’ has when dealing with a complex problem in physics – a vortex is a mass of fluid rotating on an axis and flowing towards the center. The speed of rotation is fastest at the center, and slows down as you move away thanks to the conservation of angular momentum. Whirlpools are an expression of vortexes in water, just like hurricanes and tornadoes are expressions of vortexes in the air. But what actually causes them? Well, here’s my layman’s understanding of the process.

You start with a moving mass of fluid (which can be water or air, because both are considered fluids for this purpose), which is better known as a current (in the water) or wind (in the air). The moving mass is not a single solid object, and so it will deflect if it hits an obstacle – whether solid object or another moving mass. If the deflecting obstacle is moving as well, or if the deflecting object is curved, it will cause the deflected mass to pick up a little spin. This spin is then exaggerated by the fact that the rest of the moving mass is still coming, forcing it to spin more. Thanks to the conservation of angular momentum, this forces the spinning section to pick up speed as the curve becomes tighter. A vortex is formed.

So, are whirlpools dangerous? The answer is an unequivocal it depends. Like all currents, their danger depends on how powerful they are and how experienced you are. You should always respect them and take them seriously, but you don’t need to fear them. Most of them.


Well, go ahead and fear that one. It’s the Saltstraumen Maelstrom, off the coast of Norway, and has the strongest tidal currents in the world – up 20 knots (about 23 mph, or 37 kph).  It can kill you.

Why Do The Care Bears Live On Clouds?

Man. The things I get asked.

I don’t have cable, and haven’t had it for years. This isn’t any sort of elitist “I don’t watch television” attitude, or anything. I don’t have it because my wife and I couldn’t afford it when we first got married, and by the time we could afford it we decided we’d rather afford other things instead. Because we don’t have cable, my son watches children’s programming on PBS and DVDs and the occasional YouTube video. Some of those DVDs are programs that I watched as a child. So he’s come to love old Looney Tunes and Disney cartoon shorts. And the Care Bears. He loves the Care Bears.

So recently we’re watching The Care Bears Nutcracker Suite, because I let him pick the Christmas movie we were going to watch. It’s frankly – from an adult perspective – a fairly ridiculous movie. But we’re not watching it from an adult perspective. We’re watching it from the perspective of a five year old, and he’s on the edge of his seat. And then he looks at me.

“Why do the Care Bears live on clouds?”

Uhm… Because that’s how they were designed? Which is, quite seriously, true. Here’s a sample of a couple of the original greetings cards issued by American Greetings back in 1982:
$_59 1984carebears

From the start, Elena Kucharik’s original illustrations had them on clouds. So you could argue that the answer to “why do the Care Bears live on clouds?” is “because that’s how they were designed”. But that’s a boring answer, so let’s dig a little deeper.

My first thought was to go look up the meaning of clouds as a symbol, only to get reminded that symbols are extremely dependent on the culture. I did find some interesting commonalities, though.  BibleStudyTools.com says that clouds are “a symbol of the Divine presence, as indicating the splendour of that glory which it conceals”. According to The Hidden or Implied Meaning of Chinese Charm Symbols on PrimalTrek.com, clouds “represent the heavens and also ‘good luck’ because the Chinese word for cloud (yun 云) is pronounced the same as yun (运) meaning ‘luck’ or ‘fortune'” – NationsOnline.org seems to confirm this, and further notes that Chinese “dragons are believed to be able to create clouds with their breath”. HinduWebsite.com, in Symbolism of the Cloud, Lightning, and Thunder, tells us that “White clouds are the messengers of peace, hope, and love”.

Clearly, as things that float in the sky and that provide rain, clouds have managed to pick up some very similar meanings across cultures.

I have to state at this point that – unless I can get some solid primary source evidence to the contrary – I am firmly of the belief that Elena Kucharik did not sit down to make Care Bears into symbols of the divine presence. I believe she was merely tapping into common cultural attitudes. Care Bears are soft and fluffy, and clouds are soft and fluffy. Care Bears are cute, and clouds are cute, and clouds often have rainbows which are always a huge win on anything marketed at small children. I don’t see any great mystery, really.

Still, there is something entertaining about the idea of Care Bears as mighty Loa, potent divine messengers who are the companions of cherubim and dragons. And it puts a whole new spin on the Care Bear Stare.