What is Plankton?

One night, we’re reading a book about whales. It was the prize in a kid’s meal from Chik-Fil-A, and chock full of pictures of whales and dolphins, and he loved it. So we get to the page about the Blue Whale, and he asks what it eats. “Plankton,” I tell him.

He thinks about that for a moment. “What’s plankton?”

I think about that for a moment. “Little tiny plants,” I say. “And tiny shrimp.”

“Ew,” he says, wrinkling his nose.

So there you have it. Whales eat gross stuff.

Plankton

plankton

It turns out that I was wrong. Plankton is not a type of creature, but a lifestyle – it’s defined as “the aggregate of passively floating, drifting, or somewhat motile organisms occurring in a body of water, primarily comprising microscopic algae and protozoa.” This is contrasted with nekton, which is “the aggregate of actively swimming aquatic organisms in a body of water, able to move independently of water currents.” The word comes from the German word Plankton from the Greek word plankton, meaning “wandering, drifting”. That words derives from the proto-Indo-European word *plak-, “to strike, hit”.

There are two different ways to divide plankton:  either by the kingdom the plankton falls into (phytoplankton, zooplankton, and bacterioplankton), or by whether or not the organisms are permanently plankton (holoplankton or meroplankton).

Phtoplankton

Phytoplankton, also known as microalgae, is “little tiny plants”.  They’re chlorophyll-containing organisms that float in the upper reaches of the ocean where sunlight can penetrate – generally the euphotic region, which is about 200 meters deep.  For the most part, phytoplankton is found along the coasts, in the upper northern and southern latitudes, and along the equator.

There are two magor groups of phytoplankton, dinoflagellates and diatoms.  According to NOAA, “Dinoflagellates use a whip-like tail, or flagella, to move through the water and their bodies are covered with complex shells. Diatoms also have shells, but they are made of a different substance and their structure is rigid and made of interlocking parts. Diatoms do not rely on flagella to move through the water and instead rely on ocean currents to travel through the water.”

Zooplankton

Zooplankton include the “tiny shrimp”, just like I told my son.  However, there is a whole lot more to them than “tiny shrimp”.  They include shrimp, worms, water fleas, isopods, tunicates, the larval form of larger organisms, and any other sort of poorly-swimming oceanic ocean life.  This includes jellyfish.

Zooplankton are further classified by size:

Size categories include:  picoplankton that measure less than 2 micrometers, nanoplankton measure between 2-20 micrometers, microplankton measure between 20-200 micrometers, mesoplankton measure between 0.2-20 millimeters, macroplankton measure between 20-200 millimeters, and the megaplankton, which measure over 200 millimeters (almost 8 inches).

Bacteroplankton

Many sources classify bacteroplankton as part of zooplankton, but others classify them as seperate because bacteria are in one of two kingdoms (Archaebacteria or Eubacteria) that is entirely separate from Animalia.  In brief, bacteroplankton are ocean-living bacteria, and there are a lot of them.  Estimates are that the ocean contains 3.1 x 1028 of them, which is a number I won’t type out because it is long and tedious to do so.

Holoplankton and Meroplankton

These two classifications merely describe whether the planktonic organism remains planktonic throughout its entire lifecycle.  Holoplankton are larval organisms, eventually maturing into nektonic creatures, while meroplankton are organisms that remain planktonic throughout their entire lifecycle.

So, next time you go… have fun at the beach.

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Why Is It Called A Saber-Tooth Tiger?

Every shirt my son has is his favorite shirt. I know this, because he’ll tell me. “I’m wearing my Star Wars shirt! It’s my favorite!” he’ll declare. Then, the next day, he’ll say “Mario! It’s my Mario shirt! It’s my favorite!” He’s five. He’s allowed to have multiple favorites. One of the shirts is a long-sleeved shirt with a panther on it, a shirt that I think is a team shirt for some sport or another. But that’s not why he likes it. No, he likes it because he has declared it his “saber-tooth tiger shirt”.

One day, he’s wearing that shirt and we’re watching Walking with Beasts on DVD. We hit the episode with the saber-tooth, and he gets excited. Perking up, he announces “It’s a saber-tooth!” Then he tugs on his shirt to display the panther. “It’s my saber-tooth!”

I grin at that, and keep watching. He settles back, watching wide-eyed. And then he turns to me. “Why is it called a saber-tooth?” he asks.

To be honest, the answer to the question is “because they have big, curving fangs”.

sabertooth skullLike these.

But it got me thinking about the things I don’t know about saber-tooth tigers. Particularly because of another question he asked me: “Are saber-tooths the ancestors of cheetahs and jaguars?” That, I don’t know. I think I’ve read that they’re not particularly closely related to modern cats, but I couldn’t tell you where I heard or read that or how accurate it is.

Saber-Toothed Animals

To start with, it turns out that “saber-teeth” isn’t exclusive to cats. Saber-teeth has convergently evolved in several different species. UC Berkeley’s “What is a Sabertooth?” article states that “[t]he sabertooth morphology has appeared several times during the history of the mammals”, within true cats, within two extinct carnivore families (Nimravidae and Hyaenodontidae), and among the South American marsupials called thylacosmilids. Wikipedia gets a little more specific, listing six known appearance of saber-teeth:

  • Gorgonops, a (large) dog-sized therapsid (or “mammal-like reptile”) that lived between 260 and 254 million years ago.
  • Thylacosmilus atrox, a (large) dog-sized metatherian (ancestor of the pouched mammals, including marsupials) that lived from the late Miocene to late Pilocene (about 11.6 to 2.6 million years ago).
  • Machaeroides eothen, a Terrier-sized predatory mammal that may have been a Hyaenodontidae (not closely related to Hyaenas, despite the name) that lived in Wyoming during the Eocene (56 to 34 million years ago).
  • Hoplophoneus primaevus, a North American Nimravidae (an extinct family of cat-like carnivores) that lived 38 to 33.8 million years ago.
  • Barbourofelis fricki, another Nimravidae that lived in North America from 13.6 to 5.3 million years ago.
  • Smilodon, the famous Saber-Toothed Tiger.

Could one of these animals be the ancestors of cheetahs and jaguars?

Cheetahs are Acinonyx jubatus, and are native to eastern and southern Africa and parts of Iran. Jaguars are Panthera onca, and are native to South and Central America, and the southwestern United States. Both are part of the Felidae family, but the cheetah belongs to the Felinae subfamily and the jaguar belongs to the Pantherinae subfamily. This rules out Thylacosmilus, Machaeroides, Hoplophoneus, and Barbourofelis for a few reasons – first of all, Metatherians, Hyaenodontidae, and Nimravidae are not part of Felidae. So, although they have a common ancestor, none of those animals are ancestors of any Felidae species.

Gorgonops isn’t an ancestor of cheetahs and jaguars either. The family Gorgonoopsidae is part of the Suborder Gorgonopsia, which is part of the Theriodontia group. Mammals also belong to the Theriodontia group, but fall under Suborder Cynodontia. Which is a complicated way of saying that cheetahs and jaguars and Gorgonops all have a common ancestor, but one isn’t the ancestor of the other.

But what about Smilodon?

Smilodon

There are actually three known species of Smilodon: Smilodon fatalis, Smilodon gracilis, and Smilodon populator. S. populator was the largest (about the size of a modern lion) and S. gracilis was the smallest. As a genus, Smilodon lived in North and South America from 2.5 million to 13 thousand years ago, with S. fatalis being the last of the three species to go extinct – meaning that humans may have overlapped with the last of the Smilodons. Smilodon is a genus within the Machairodontinae subfamily of family Felidae, so they are true cats.

Despite being true cats, they weren’t the ancestors of cheetahs or jaguars. Not in any meaningful sense, anyway. First of all, they were in the wrong geographic area to be the ancestors of cheetahs – you know, with cheetahs in Africa and Smilodon in North and South America. Their range did overlap with the jaguar (or, at least, with the jaguar’s ancestors), but they really aren’t the ancestor of jaguars. As mentioned, jaguars are part of the Pantherinae subfamily of Felidae. Smilodon is part of the Malchairodontinae subfamily, so they have ancestors in common with the Pantherinae but aren’t otherwise related.

This is not to say that Smilodon and the ancestors of jaguars couldn’t have mated. After all, much like Las Vegas, what happens in the wild stays in the wild. However, breeding two different species within the same genus often results in sterility, because the specific numbers of chromosomes may not match. Donkeys and horses, both family Euidae and genus Equus are an obvious example of this. The discrepancies are only magnified if you step up past genus to family.

Still, it could have happened. And it is possible (if not likely) that a single “jaguodon” could have managed to be born fertile. So quick, let’s do some math. A jaguar hits sexual maturity at age 2 and has 38 chromosomes. Smilodon fatalis went extinct about 13,000 years ago, so that’s 6,500 generations for the “jaguodon” and her descendants, which start at 50% Smilodon – so, 19 Smilodon chromosomes.  Assuming mama “jaguodon” breeds with a jaguar, her kittens have 9.5 Smilodon chromosomes, and 28.5 jaguar chromosomes.  This continues for the next, oh, call it 6,000 generations (we’ll assume a small degree of individual jaguars that happen to have Smilodon DNA breeding with other jaguars that happen to have Smilodon DNA).  That means that any given jaguar might have 38/26000 Smilodon chromosomes, which is 2.5 x 10-1805 chromosomes.  Which means that any given jaguar could be around this much Smilodon:

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Clearly, that’s not much Smilodon in your jaguar.  So, while the fearsome “saber-tooth tiger”could (in theory, at least) be an ancestor of a given jaguar, we don’t really need to worry about saber-toothed jaguars suddenly being born.

How Do You Get To Space?

We’ve got another contextless question here. Just the question “how do you get to space?” listed in my notes. I strongly suspect, though, that it has to do with my son’s current obsession with Star Wars. There’s a lot of space ships in those movies, after all, and he’s got a toy Millennium Falcon that he abuses in true five-year-old fashion. So he thinks about space – or at least movie “space” – a lot.

What Is Space?

Generally speaking, “space” is “outside Earth’s atmosphere”. Specifically, though, this gets problematic. There’s six different layers of the atmosphere, after all:

  • The troposphere, which averages about 7 miles (11 km) thick, and ranges from 8 km thick at the poles to 16 km at the equator. This is what most of us think of as “the atmosphere”, with breathable air and weather and most of clouds. The temperature drops with altitude in the troposphere.
  • The stratosphere, which sits on top of the troposphere and extends upwards to 30 miles (45 km) above the Earth’s surface. You find the ozone layer here, as well as temperature increasing slightly with altitude – up to a high of 32 degrees Fahrenheit (0 degrees Celsius).
  • The mesosphere, which sits on top of the stratosphere and extends upwards to about 53 miles (85 kilometers) above the surface. Temperature begins dropping with altitude again in this layer, reaching a low of -130 degrees Fahrenheit (-90 degrees Celsius), and it’s the atmospheric layer in which meteors begin to burn up as they fall towards Earth.
  • The thermosphere, which sits on top of the mesosphere and extends upwards to about 372 miles (600 kilometers) above the surface of the Earth. Temperatures can reach thousands of degrees (Celsius or Fahrenheit), but it’s measured in the energy of the molecules of gas in this layer and there’s not a lot of molecules that high up (the average molecule would have to travel 0.62 miles/1 kilometer to collide with another molecule), so it doesn’t feel hot.
  • The exosphere, which sits on top of the thermosphere and extends upwards to about 6,200 miles (10,000 km).
  • The ionosphere, which starts 30 miles (48 km) above the surface and stretches to 600 miles (965 km) above the surface. That’s an average figure, though, as it grows and shrinks based on solar conditions. It’s also divided into sub-regions, based on what wavelength of solar radiation it absorbs. Note that the ionosphere, although considered a seperate layer of the atmosphere, overlaps the mesosphere, the thermosphere, and the exosphere.

So, where’s space? The definition “outside Earth’s atmosphere” could mean that you have to exit the exosphere to be “in space”, but this would put us in the ridiculous position of having to consider the International Space Station (which orbits at an average height of 249 miles) within the atmosphere. Clearly, that’s ridiculous.

The commonly accepted altitude definition for space is the Kármán line, which is 62 miles (100 km) above sea level. This line, sitting in the lower reaches of the thermosphere, is approximately the altitude above which wings no longer provide lift and below which atmospheric drag makes orbital paths fail without forward thrust.

Ways to get to space

Clearly, then, to get into space “all” we have to do is travel at least 62 miles (100 km) straight up. Simple, right? Well, maybe not. At present, we have only a handfull of ways to leave the surface of the Earth: balloons, really big guns, rotor wing aircraft, fixed-wing aircraft, and rockets. Each has some advantages and disadvantages.

Balloons

For balloons, the current record-holder for unmanned flight is the Japanese BU60-1, which reached an altitude of 33 miles (53 km) and carried a 10 kg payload. The altitude record for a manned balloon was the StratEx, which reached an altitude of 25.7 miles (41.4 km). Both were impressive achievements, but neither made the Kármán line.

Balloons function because of Archimedes’ Principle:

When a body is fully or partially submerged in a fluid, a buoyant force Fb from the surrounding fluid acts on the body. The force is directed upwards has a magnitude equal to the weight, mfg, of the fluid that has been displaced by the body.

In other words, if an object is submerged in a fluid but is lighter than that fluid, the fluid pushes it up until the object it is the same weight as the surrounding fluid. And while we don’t tend to think of it in this fashion, our atmosphere behaves like a fluid. We don’t float in the air because we’re denser then the air. A balloon inflated with air doesn’t float, because it’s actually slightly more dense than the atmosphere (because you forced more air in to inflate the balloon). But balloons filled with hot air, or with a gas that is less dense than our atmosphere (hydrogen or helium, say) will float.

Because of this, you could theoretically float a balloon into space – all you need is for the balloon to be less dense than the surrounding environment, after all. There’s a catch, though. The material of the balloon needs to be strong enough to not burst if the interior is pressurized, strong enough not to be crushed by the denser exterior, and light – because the mass of the balloon is added to the mass of the interior to determine if Archimedes’ Principle will lift it. A vacuum would be the ideal interior, but so far we don’t have anything simultaneously strong enough to keep the atmosphere from crushing a vacuum balloon and light enough for the air to push it up.

Big Gun

Jules Verne proposed this in From the Earth to the Moon way back in 1865. All you need is enough power, and you can launch something (or someone) into space from the ground. How much power? Well, using a ballistic trajectory calculator and assuming that the projectile is fired straight up from sea level, you would need a muzzle velocity of 4,595.52 feet per second (1,400.715 meters per second) to launch something 100 kilometers into the air – ignoring the effects of atmospheric drag. If you’re curious, that’s 142.78 times the force of gravity.

This is clearly not a good way to put people into space, but it would work well for launching non-fragile items. And in 1966, Project HARP demonstrated that it would work. A 16-inch (and 119 feet long) gun constructed by the US Department of Defence in Yuma, Arizona fired a 165 pound shell 590,000 feet (179,832 meters) into the air on November 19, 1966 – that’s 111.74 miles (179.8 kilometers), putting it well past the Kármán line

Plane

Planes seem an obvious choice, right? We all know what they are, they take off and land, so why not fly into space? Well, there’s a good reason for that – the Kármán line (meaning that by the time you reach space your wings aren’t working) and the propulsion (both jets and propellers require air to function). So, any plane that could reach space would need to be a rocket as well as an airplane. Right now, the world altitude record for a airplane was set on August 31, 1977 by Alexander Fedotov, who reached 23.4 miles (37.66 kilometers) in a MiG-25.

Rocket

Right now, this is the way we get to space. A rocket engine carries stored fuel and utilizes Newton’s third law by expelling that fuel in one fashion or another from one end of the craft to push the opposite direction. Most rockets in operation are combustion rockets, meaning that the fuel is ignited and burned in some fashion. These can be quite expensive, as the rocket has to lift all of its fuel at the time of launch. However, with sufficient fuel and engineering and money, you can build a rocket capable of reaching any altitude.

Other Strategies

Any number of launch methods that do not rely on rockets have been proposed – the space gun technically is counted in this category, but it differs from the others in the fact that it has actually been constructed. Most of the others have a US Department of Defense technology readiness level of 2, meaning that they are dependent on the invention of the materials and technologies needed to support them, and may not actually be feasable. They include:

  • Space tower: a tower that reaches above the Kármán line, possibly as far as geosynchronous orbit (22,369 miles or 36,000 km).
  • Skyhook: A satellite that lowers a lift cable (or the equivalent) and then reels in the payload.
  • Space elevator: A tether attached to the Earth at one end and a geosynchronous satellite at the other, which can then allow vehicles to climb into space.

How do you stay in space?

To quote Randall Monroe, “getting to space is easy. The problem is staying there.” Why? Well, gravity is still pulling you down. So, you have to go ‘sideways’ fast enough that you keep missing the Earth as you fall (which is pretty much what an orbit is). Using the Earth Orbit Velocity calculator on Hyperphysics, an orbit at the Kármán line would require an orbital speed of 25,745.41 feet per second (7847.2 meters per second), which translates to 17,549.1 mph (28,249.64 kph).

Fortunately, you don’t have to maintain constant acceleration at that speed – one of the defining features of space is that it’s pretty empty, meaning there isn’t a whole lot out there to slow you down once you get going. But still, you have to get going really fast to stay there – orbiting at the Kármán line means you circle the earth every 1.45 hours.

How do you get back down?

Oh, that’s easy. You fall. Whether or not you die is a matter of how you land.

What is a Theory?

I’ll be honest: this article has nothing to do with a question my son asked, but it has everything to do with a show I was watching with him.

My son watches PBS the way most other kids his age watch Nick, Jr. or the Disney Channel. This has nothing to do with his mom and dad being snooty liberal types, and everything to do with the fact that his mom and dad are too cheap to pay for cable. Instead we have rabbit ears and one of those digital signal converters, and PBS comes in over the airwaves.

Anyway, I’m watching Thomas Edison’s Secret Lab with my son. It’s an odd little science show, with robots and a hologram of Thomas Edison, but it tries to teach science. The episode we’re watching is about one of the characters making a youth potion because he resents being too big to ride on his favorite amusement park ride, and this lead to an explanation of cell division and telomeres and the role they seem to play in aging. Then, one of the characters tells him that this is “just a theory” and “hasn’t been proven”.

That threw a huge red flag up for me.

Theory

The word “theory” has multiple definitions, of course. After all, it’s an English word. Here they are:

  1. a coherent group of tested general propositions, commonly regarded as correct, that can be used as principles of explanation and prediction for a class of phenomena: Einstein’s theory of relativity. Synonyms: principle, law, doctrine.
  2. a proposed explanation whose status is still conjectural and subject to experimentation, in contrast to well-established propositions that are regarded as reporting matters of actual fact. Synonyms: idea, notion hypothesis, postulate. Antonyms: practice, verification, corroboration, substantiation.
  3. Mathematics. a body of principles, theorems, or the like, belonging to one subject: number theory.
  4. the branch of a science or art that deals with its principles or methods, as distinguished from its practice: music theory.
  5. a particular conception or view of something to be done or of the method of doing it; a system of rules or principles: conflicting theories of how children best learn to read.
  6. contemplation or speculation: the theory that there is life on other planets.
  7. guess or conjecture: My theory is that he never stops to think words have consequences.
  8. (Idiom) in theory, ideally; hypothetically:

The problem with the word “theory” is that when it is used in common speech, it generally is used to mean something like the second or fifth definition. Theories are seen s somehow unproven; they’re things that need testing, unlike laws.

In science, theory most commonly refers to the first definition. LiveScience.com gives a good explanation of what a scientific theory is:

The University of California, Berkley defines a theory as “a broad, natural explanation for a wide range of phenomena. Theories are concise, coherent, systematic, predictive, and broadly applicable, often integrating and generalizing many hypotheses.”

Any scientific theory must be based on a careful and rational examination of the facts. Facts and theories are two different things. In the scientific method, there is a clear distinction between facts, which can be observed and/or measured, and theories, which are scientists’ explanations and interpretations of the facts.

An important part of scientific theory includes statements that have observational consequences. A good theory, like Newton’s theory of gravity, has unity, which means it consists of a limited number of problem-solving strategies that can be applied to a wide range of scientific circumstances. Another feature of a good theory is that it formed from a number of hypotheses that can be tested independently.

They are also distinct from scientific laws:

A law is a description of an observed phenomenon that hold true every time it is tested. It doesn’t explain why something is true; it just states that it is true. A theory, on the other hand, explains observations that are gathered during the scientific process. So, while law and theory are part of the scientific process, they are two very different aspects, according to the National Science Teachers Association.

Hypothesis

A hypothesis is distinct from a theory and, in fact, supports the validity of a theory:

  1. a proposition, or set of propositions, set forth as an explanation for the occurrence of some specified group of phenomena, either asserted merely as a provisional conjecture to guide investigation (working hypothesis) or accepted as highly probable in the light of established facts.
  2. a proposition assumed as a premise in an argument.
  3. the antecedent of a conditional proposition.
  4. a mere assumption or guess.

Please Don’t Confuse Them

A hypothesis is a testable proposition, a statement of an attempt to explain how and why a specific phenomena occurs. A theory is a general explanation for how and why some group of related phenomena work, that makes testable predictions and is supported by multiple observations and experiments. Evolution is a theory. Germs causing disease is a theory. Gravity is a theory. The structure of the atom is a theory. Theories are, in the end, things that are true as far as they go. Newtonian Physics was a theory, and it still is. But it was superseded by General and Special Relativity, which is also a theory.

So don’t dismiss something, because it’s “just a theory”.

Are Polar Bears Real?

Sometimes, you get the simple questions.

Like so many of my son’s questions, this one came while we were in the car. We’d run a few errands and were heading back towards our house. I was paying attention to my driving, and he was playing with the new toy pterodactyl he’d saved up his chore money to buy, and then out of nowhere he asks that question. “Are polar bears real?”

That’s it. Just a random question out of the blue.

“Yes,” I answer. Satisfied, he starts telling me about how his pterodactyl is a nice pterodactyl, and how it only eats bad guys. So, no. I have no idea what prompted that question.

Polar Bears

Just to restate the obvious, polar bears are real. Look. Here’s a picture:

polar bear

Biologically, the polar bear is Ursus maritimus, meaning “a bear of the sea” or “a marine bear”. At present, their population is estimated at 20,000 to 25,000 worldwide, with their primary habitat on the sea ice of the Arctic Ocean. They are specifically adapted for a polar marine environment, and are generally classified as marine mammals Males grow to be between 8 and 9 feet (2.4 to 2.6 meters) from nose to tail and up to 1,760 lbs (800 kg), while females generally reach 6 to 7 feet (2 meters) and “only” up to 880 lbs (400 kg). Interestingly enough, they swim using only their front paws – the rear are held flat and used to help steer.

Sadly, it is possible that polar bears may not be real in the near future. Not in the wild, at least. They are classified as a vulnerable species by the International Union for Conservation of Nature, which means they meet any of the following criteria (as defined in the IUCN Red List Categories and Criteria) and are “therefore considered to be facing a high risk of extinction in the wild”:

  • A significant reduction in population over the past 10 years or three generations, whichever is longer (50% or more if the cause is reversible, understood, and has stopped; 30% or more if the cause is not understood, or has not ceased, or is not reversible).
  • A significantly restricted geographic range (less than 20,000 square kilometers with fragmented populations, declining geographic range, or extremely fluctuating range).
  • A population of less than 10,000 mature individuals with a continuing population decline of at leat 10% in the last 10 years or 3 generations.

The polar bear specifically has a Vulnerable A3c rating, meanig it is vulnerable because there is a projected population reduction of greater than 80% over the next 10 years/3 generations, due to a decline in area of occupancy, extent of occurrence, and/or quality of habitat.

Why?  Well…

Global Warming

Yep. That perennial scientific consensus and political football, global warming. The primary habitat of polar bears is Arctic sea ice, with nursing females actually making dens on the ice. The Arctic sea ice minimums are declining at an average rate of 13.4% each decade, relative to the 1981 – 2010 average, meaning less sea ice is available for them. And while they can swim and are considered marine mammals, they aren’t aquatic animals. They still have to climb out of the water.

They aren’t the only animals impacted by global warming, but they’re kind of the poster child for it. As Simon Stuart, Chair of IUCN’s Species Survival Commission says:

“Climate change will be one of the major drivers of species extinctions in the 21st century. In order to slow the pace the adverse effects of climate change are having on species around the world, we must work to reduce use of energy from fossil fuels and ensure that our leaders make and adhere to strong commitments to cut greenhouse gas emissions now.”

Grolar Bears

One possible side-effect of polar bear habitat change is the “grolar bear” an uncommon half-polar bear, half-grizzly bear that, until 2006, was only known to exist in zoos. The first confirmed wild grolar was described as having “white fur… interspersed with brown patches. It also had long claws, a concave facial profile, and a humped back, which are characteristic of a grizzly.”

grolar bear

DNA analysis showed that the bear’s father was a grizzly and his mother a polar bear. According to the geneticist who studied the grolar bear, grizzly and polar bears are the most closely related of any living bear species, close enough tha tthe hybrid could have successfully mated with either parent species. The hybridization was considered unusual, because – although grizzly and polar bear habitats do overlap in the Canadian Arctic, the encounters are generally aggressive. As a result, they aren’t common. As of 2012, there were only five confirmed sightings.

Do They Eat Penguins?

No. I mean, they probably would if given the chance. Generally speaking, though, polar bears don’t go south of Hudson Bay. The furthest north you find penguins is the Galapagos Islands. As a result, polar bears don’t eat penguins for the same reasons that bengal tigers don’t eat llamas – lack of opportunity.

Where Is Heaven?

Several months ago, we took a family trip to my dad’s grave. It’s something I like to do annually, either on Memorial Day or near Halloween, as a way of remembering my father.
Last year, we went shortly after Halloween – the first time since my son was born that we made the trip. Both my wife and I felt that he was too young before that to go to a cemetery.

Keep this fact in mind, because it will momentarily be important background information.

One day, out of the blue, my son looks at me and asks “Daddy, where’s heaven?”

This is one of those interesting questions that a five-year-old can come up with.  “Well,” I say, “different people have different beliefs about…”

“I’ve been there,” he declares.

“What?”  Followed by “You have? When?”

“When I saw my great-great-great-grandfather.”

No idea what he’s talking about here. Plus, he’s only got the vaguest grasp on what a great-grandparent is anyway. “You did? When?”

He gives me that exasperated five-year-old look. “Remember? It had all the white stones in the ground.”

I stare at him for a minute, and then it clicks. “You mean the cemetery? When we saw your Grandpa Gant’s grave?”

“Yes!” he declares. “Where is it?”

Since then, I’ve tried more than once to convince him that cemeteries aren’t heaven. But, because this blog is all about answering my son’s questions – no matter how strange – let’s take a stab at this.

The Cemetery

CampNelson

Let’s start with where my son thinks Heaven is. My fater is buried at the Camp Nelson National Cemetery in Nicholasville, Kentucky. Based on this, Heaven started out as a US Army camp in the American Civil War, used as a supply base, a hospital, and an enlistment station for African-American soldiers.

The cemetery itself started out as a small cemetery to bury soldiers who died at the hospital. The site became a National Cemetery in 1866, and in 1868 Civil War dead from nearby towns in Kentucky were relocated to the camp and reinterred. At present, only the following people can be buried there:

  • Members of the armed forces how have met minimum active duty requirements and who did not receive a dishonorable discharge.
  • Spouses and surviving spouses of the above.
  • Minor dependent children of the above (and, under certain conditions, unmarried adult children)

So, according to my son, the surest path to Heaven is to join the US Armed Forces and then follow US-27 south from Lexington, and then hang a left on Danville Road. Clearly, this is not a consensus opinion.

Beliefs About The Location Of Heaven

I could probably write several long, long books about the beliefs of any given religion about the location of their Heaven. Heck, I could probably write several long, long books about the beliefs of any given sect of a religion about the location of Heaven.  Fascinating as that might be, it’s far beyond the scope of this blog. So, I’m going to focus on the major religions of the world.

To decide which religions are the “major” ones, I used demographic information from the Pew Research Center. As of 2011, the largest religions in the world were Christianity, Islam, Hinduism, and Buddhism – together, they account for 76.8% of the world’s population.

Christianity

It can be argued that the writers of the New Testament believed that there was a location of some sort for Heaven – physical descriptions abound (streets of gold, mansions, and so forth). The closest the New Testament gets to giving that location, though, is in 2 Corinthians 12:2:

I knew a man in Christ above fourteen years ago, (whether in the body, I cannot tell; or whether out of the body, I cannot tell: God knoweth;) such an one caught up to the third heaven.

However, the consensus opinion among modern Christians is that the “Third Heaven” is not a specific, physical place – it is the dwelling place of God, and the descriptions are metaphors instead of literal places and things.  It’s a real place, but it’s a spiritually real that doesn’t have a physical location.  Although the terms are never specifically used in the Bible, the “first heaven” is the sky and the “second heaven” is space (or, more accurately, where the sun, moon, and star are found).

Islam

Much like Christianity, Janna (Paradise or Heaven) has a very physical description in the suras of the Qur’an – it is described as a garden, with rivers of water and milk and wine, with fruit trees and golden thrones and palaces.  Also, much like Christianity, Janna is not generally believed to be a physical location – it is a spiritual thing.  (I think.)

Hinduism

Not knowing much about Hindu beliefs at all, I’ll just quote from Hinduism: The Ideas of Heaven and Hell and hope that, since it matches up with a few other sources I found online, this was a good source:

According to the Hindu Puranas, there are fourteen worlds in the universe – the seven upper and the seven lower. The seven upper worlds are Bhuh, Bhavah, Swah, Mahah, Janah. Tapah, and Satyam; and the seven nether worlds are Atala, Vitala, Sutala, Rasatala, Talatala, Mahatala, and Patala. The region known as Bhuh is the earth where we dwell, while Swah is the celestial world to which people repair after death to enjoy the reward of their righteous actions on earth. Bhuvah is the region between the two. Janah, Tapah, and Satyam constitute Brahmaloka, or the highest heaven, where fortunate souls repair after death and enjoy spiritual communion with the personal God, and at the end of the cycle attain liberation, though a few return to earth again. The world of Mahah is located between Brahmaloka and Bhuh, Bhuuah, and Swah. Patala, the lowest of the seven nether worlds, is the realm where wicked souls sojourn after death and reap the results of  their unrighteous actions on earth. Thus, from the viewpoint of Hinduism, heaven and hell are merely different worlds, bound by time, space, and causality.

So, it appears that – if I’m interpreting this right – Hindu belief in Heaven (and Hell) is that they are actual locations, but they are not something you can point to on a map.  Instead, they are different universes or dimensions.

Buddhism

For this, I’m using The Buddhist Conception of Heaven and Hell, which tallies up with my scanty knowledge of Buddhism (derived primarily from short essays and a few popular books).  Heaven and Hell are, for Buddhists, temporary places that can be found on Earth or in spiritual realms.

Heaven is a temporary place where those who have done good deeds experience more sensual pleasures for a longer period. Hell is another temporary place where those evil doers experience more physical and mental suffering. It is not justifiable to believe that such places are permanent. There is no god behind the scene of heaven and hell. Each and every person experiences according to his good and bad kamma.

Unexpected Astronomy!

Here’s the thing, though.  I grew up Mormon, and Mormons simply do not march to the beat of the same drummer as mainstream Christianity.  For them, Heaven is a physical place with an actual location in the universe.  And if you know Mormon scripture, there’s even hints on where to look.  For that, go to the Pearl of Great Price, and check out the Book of Abraham, Chapter 3:

  1. And I, Abraham, had the Urim and Thummim, which the Lord my God had given unto me, in Ur of the Chaldees;
  2. And I saw the stars, that they were very great, and that one of them was nearest unto the throne of God; and there were many great ones which were near unto it;
  3. And the Lord said unto me: These are the governing ones; and the name of the great one is Kolob, because it is near unto me, for I am the Lord thy God: I have set this one to govern all those which belong to the same order as that upon which thou standest.
  4. And the Lord said unto me, by the Urim and Thummim, that Kolob was after the manner of the Lord, according to its times and seasons in the revolutions thereof; that one revolution was a day unto the Lord, after his manner of reckoning, it being one thousand years according to the time appointed unto that whereon thou standest. This is the reckoning of the Lord’s time, according to the reckoning of Kolob.
  5. And the Lord said unto me: The planet which is the lesser light, lesser than that which is to rule the day, even the night, is above or greater than that upon which thou standest in point of reckoning, for it moveth in order more slow; this is in order because it standeth above the earth upon which thou standest, therefore the reckoning of its time is not so many as to its number of days, and of months, and of years.
  6. And the Lord said unto me: Now, Abraham, these two facts exist, behold thine eyes see it; it is given unto thee to know the times of reckoning, and the set time, yea, the set time of the earth upon which thou standest, and the set time of the greater light which is set to rule the day, and the set time of the lesser light which is set to rule the night.
  7. Now the set time of the lesser light is a longer time as to its reckoning than the reckoning of the time of the earth upon which thou standest.
  8. And where these two facts exist, there shall be another fact above them, that is, there shall be another planet whose reckoning of time shall be longer still;
  9. And thus there shall be the reckoning of the time of on eplanet above another, until thou come nigh unto Kolob, which Kolob is after the reckoning of the Lord’s time; which Kolob is set nigh unto the throne of God, to govern all those planets which belong to the same order as that upon which thou standest.

So, for Mormons, it appears that Heaven is the planet with the slowest revolution and longest orbital period around the greatest star in the universe.  “Greatest” isn’t defined here, but it could be either “largest” or “brightest”.  Conveniently, Phys.org has an article titled What is the biggest star in the universe? to give us a few tips:

  • At present, the largest star we know of is UY Scuti, about 9,500 light years from Earth in the Scutum constellation.  It has a 1.2 billion kilometer diameter, meaning that if it replaced the Sun in our solar system it would eat Jupiter.
  • The heaviest star we know of is  R136a1 in the Large Magellanic Cloud (about 165,000 light years away), which may be as much as 265 stellar masses.  It was even bigger when it first formed, possibly as much as 310 solar masses, but it blasts about an earth worth of mass off every 22 days in the form of it’s solar wind.  Since it’s about twice the theoretical upper limit for star size, it’s believed to be both created from two or more stars colliding and likely to hypernova at any time.

The brightest object in the heavens, though, has the unpronouncable name SDSS J010013.02+280225.8, and it outshines everything.

This object, known affectionately as “J0100+2802”, is a quasar.  More specifically, it is a black hole with approximately 12 billion solar masses (making it 3,000 times more massive than Sagittarius A*, the supermassive black hole at the center of the Milky Way).  It’s roughly 12.8 billion light years from Earth, 429,000,000,000,000 times brighter than our Sun, and 7 times brighter than the previous holder of the “brightest quasar in the universe” title.  So that looks like a great place to start looking.

Ultimately, of course, the location of Heaven is a matter of faith.  It really doesn’t matter if it’s 12.8 billion light years from Earth, or in a realm that exists for spirits only, or if it’s a state of mind based on the actions and decisions of your life.  What does matter is what it inspires you to do.