Hi, I'm Emily from MinuteEarth and this is not a pipe.
Although, you may already know that if you speak French.
But in real life,
objects don't always come with a helpful label, and it can be really hard to determine what things are, or are not.
Coming up: four quick videos to try to set the record straight,
starting with bees.
Close your eyes—no, seriously, close your eyes—and imagine a bee.
Now open your eyes. You probably imagine something with yellow and black stripes, like a honeybee.
But,
bee-lieve it or not,
most bees aren't yellow and black striped,
and what's even more confusing,
is that there are lots of stripy "bees" that are not actually bees.
They're flies, wasps, and even moths,
yet they look so much like our idea of a bee that we're constantly getting fooled.
But we are not actually the ones they're out to bedevil.
Many insects that can defend themselves have bright patterns that teach predators to keep their distance.
Say two hypothetical stinging species have different warning colorations.
A predator must sample lots of individuals of each before learning that both patterns
yield unhappy meals.
Yet, if the two species look similar, far fewer of each kind will get chomped
before the predator learns to avoid that pattern.
So stinging species,
like bees and wasps, often end up converging on a single appearance.
Once predators learn that yellow and black striped prey isn't worth the risk,
cheaters creep into the system. Neither flies nor moths have stingers for defense,
but simply looking like an insect that does provides pretty much the same protection.
So is that insect a bee, or not a bee? If it just stung you, it's a bee or a wasp.
Along with stingers, both have short elbow-shaped antennae and four wings,
although those can be hard to see.
Bees are the super hairy ones, while wasps are mostly bald. On the non-stinging side, if it has two wings and looks like it's
wearing giant goggles, it's a fly. If it has long feathery antennae,
it's probably a moth. If you can get beyond the fear of getting stung and begin to appreciate their differences,
you may find that beauty is in the eye of the beholder. Or,
the not-a-bee-holder.
For the record, it's really hard to get close enough to see elbow-shaped antennae without getting stung. I've tried.
One thing that won't sting you―at least not on purpose―
pine trees.
Or wait, is this a pine?
This is not a pine tree.
Neither is this, or this.
In fact, most of the images that pop up in a Google Image Search for pine trees aren't pine trees. Now,
it's not surprising that many people call all of these trees pines,
because they are related to pines, but calling them pines is like calling this a dog, and this a dog, and this a dog.
They're related to dogs, but they're not dogs.
So to set things straight
scientifically, pines and the trees they get confused with differ in the shape and size of their needles and cones, as well as their overall
shape. True pines have needles in bunches of two, three, or five, and
seeds that are released from scaly downward-hanging cones that take two years to mature, which is what gives their scales those two distinct parts:
the first year's growth, and the second year's growth. And most pines don't actually have that stereotypical Christmas tree shape,
unless they're pruned that way. Pines on their own have irregular rounded or tiered canopies, like this, or
this, or this. As much as people want to call this a pine,
it isn't. It is a cousin, though. A spruce. You can tell spruces from pines by their squarish,
Individual needles held in a bottle-brush shape and their cones' scales that take only one year to grow, and the fact that they look
like Christmas trees, no pruning required. Here's another closely-related pine impostor,
the fir tree. Its
distinguishing features are cones that stand upright, and whose scales come off with the seeds attached, rather than opening to let the seeds fall out.
Firs also have flat needles coming off their branches in a flatter horizontal pattern than spruces, and they also look like Christmas trees.
Then there's the Douglas fir, which also isn't a pine, but it isn't a fir either. Its cones
hang down not up, have scales that open rather than fall off, and have little extra scales that look like mouse butts.
Douglas fir's closest cousin is actually the larch, the only member of the family with leaves that fall off in the winter.
The family goes on and on, and with such diversity of features,
It's no surprise that keeping them all straight can be a tall order.
So just start with this: a pine is a non-deciduous,
irregularly-canopied, coniferous tree with
two-colored scales on its downward hanging cones, and needles in bunches of two, three, or five. All these others aren't pines,
but they are members of the grand and tremendous house of Pinaceae.
There's also Pinaceae's cousin, Canuseeae. As in, can you see a dinosaur?
It turns out that some of the things we've been calling dinos are really di-NOs.
This is
not a dinosaur, but it used to be. For centuries, as we tried to make sense of the diversity of life on Earth,
we created animal families according to looks alone. And
dinosaurs were basically anything that was big and scary and scaly and dead, but that doesn't actually make a lot of sense.
It's a lot like if you looked at all of humanity and assumed all the Conan O'Brien look-alikes belonged in one family, and
bearded people in another, and people with bad posture in another, and everyone with unibrows in another.
Not only would you have to make ridiculous decisions along the way, like what to do with Conan O'Brien look-alikes with unibrows,
but perhaps one of the people with bad posture actually has more in common with the bearded people than the rest of the bad posture
family. You'd end up with families that aren't families, and that's why we draw our human family trees according to actual
relationships, like parents and grandparents and brothers and sisters.
Evidence from fossils and DNA have shown us that all living things are related and that we can construct
animal families by finding species' most recent common ancestors. So despite the fact that whales have fins,
they're more closely related to hippos than to fish.
And even though sloths are long-armed and hairy and climb trees, their cousins are ant eaters and armadillos.
The big, scary, scaly, dead group of animals belong to several different families. Some, the group
we now call dinosaurs, belong to a branch that includes modern-day birds.
Others share family ties with today's snakes. And we can trace our own family trees back to our great-great-
great-great aunt,
the Dimetrodon.
Which is surprising. I was expecting my great-great-great aunt to look more like this.
Last up, everyone knows what THE moon is. But what about a moon?
It's not as black and white as it looks.
Until relatively recently,
humans believed everything we could see in the sky was orbiting around the Earth. Of course,
the moon was the only thing actually orbiting the Earth, and the Earth itself was orbiting a star.
But there were other objects orbiting that star that also had things orbiting them,
so we decided to call all of those secondary satellites moons too.
Nowadays, when people say moon, they essentially mean a natural satellite of a satellite of a star, which seems to capture our
collective intuition for what distinguishes a moon.
However,
there is a problem.
Space rocks come in all sorts of shapes and sizes and behave in many ways,
many of which don't seem at all like our traditional idea of a moon.
We could at this point give up and say, "okay, all these things are moons."
But in this video, we're gonna defend the idea that "moon" is a special title,
and we shouldn't award it too broadly. To start with, through improvements in technology,
we've ended up calling smaller and smaller things moons.
We've already identified more than 60 increasingly small moons orbiting Saturn alone,
some of which are essentially kilometer-wide rocks hiding in its rings.
It's inevitable that we'll keep identifying ever-smaller individual chunks orbiting planets.
So, if we don't set some lower limit on moon sizes,
are we willing to think of each of the billions of tiny rocks and dust particles in Saturn's rings, and
every last speck of dust orbiting the Earth, as moons? At the other extreme,
some moons are too big to be considered moons.
Pluto and it's maybe-moon Charon are close enough in size that it's really fair to say they both orbit each other.
In fact,
technically, anytime anything orbits any other thing they're actually both orbiting their common center of mass,
called the barycenter. Where that point is depends on the relative masses of the two objects.
If one is way bigger than the other, like the Earth, the barycenter will be close to or even inside it,
so it feels right to say that the smaller one is orbiting around the bigger one.
But when they're almost the same size, like with the binary
asteroid 90 Antiope, the barycenter will be almost
halfway between, and it really doesn't make sense to call one or the other or both of them "moons."
So where in the continuum of size ratios, aka who's really orbiting who and by how much,
where should we stop calling something a moon?
Maybe the ratio of sizes doesn't accurately capture your intuition about what a moon is.
Maybe
absolute size would be better. Or, the roundness of the candidate moon. Or, whether it can be seen from the surface of its planet. Or,
whether it has a regular elliptical orbit.
Or, maybe there's simply no one definition for a moon that captures both the
complexity of the different ways that stuff can orbit other stuff, and our nebulous intuitive
"I know it when I see it" idea of what makes a moon.
Unless you're planning on doing a lot of space travel,
you're probably safe with the "I know it when I see it" rule for spotting moons.
But the bottom line here is that names are both arbitrary and deceptive. With that in mind, I'm
"Emily."
Thanks for watching.