#technically fiction

Big bees buzz in Minecraft. In our world, blocky bees might starve and be stuck on the ground. Yet long ago, giant insects did roam our planet.

Visit a flower forest in the game Minecraft and you may stumble across big, blocky bees searching for blooms. In real-world terms, those boxy behemoths measure a whopping 70 centimeters (28 inches) long. They’d be similar in size to a common raven. And they’d dwarf any insects alive today.

The world’s biggest modern bees, found in Indonesia, max out at around 4 centimeters (1.6 inches). But shockingly large insects aren’t much of a stretch. You’d just need to go back in time. A very long time ago, gargantuan grasshoppers and massive mayflies cruised the planet.

The largest known insects that ever lived were ancient relatives of dragonflies. Belonging to the genus Meganeura, they lived roughly 300 million years ago. These behemoths had wings spanning around 0.6 meter (2 feet). (That’s similar to the wingspan of a pigeon.)

Other than size, these creatures would have looked like modern dragonflies, says Matthew Clapham. He’s a paleontologist at the University of California Santa Cruz. These ancient insects were predators, he says, and likely ate other insects.

Back 220 million years ago, giant grasshoppers flitted about. They had wingspans stretching 15 to 20 centimeters (6 to 8 inches), notes Clapham. That’s similar to the wingspan of a house wren. Large relatives of mayflies also moved through the air. Today, those insects are known for their short lifespans. Their ancient relatives’ wings spanned some 20 or 25 centimeters, about three-fourths that of today’s house sparrows. There even were massive millipedes and roaches.

Scientists think such colossal creepy crawlies evolved because of a bump in the amount of oxygen in the air. The Carboniferous period was from 300 million to 250 million years ago. Back then, oxygen levels reached around 30 percent, scientists estimate. That’s a lot higher than the 21 percent in air today. Animals require oxygen for metabolism, the chemical reactions that power their bodies. Bigger creatures tend to use more oxygen. So extra oxygen in the atmosphere may have provided the conditions for large insects to evolve.

The first insects appeared in fossils from around 320 million or 330 million years ago. They started out pretty big and hit their peak size quickly, Clapham says. Since then, insect sizes have mostly gone downhill.

Explainer: What is a computer model?

Clapham and his colleagues use computer models to investigate the prehistoric atmosphere. Earth’s oxygen levels relate to the balance of photosynthesis and decay.  Plants use sunlight and carbon dioxide to fuel their growth. This process add oxygen to the air. Decaying matter consumes it. The scientists’ work suggests oxygen levels started dropping around 260 million years ago. The levels then fluctuated over time. For much of insects’ history, oxygen levels and wing sizes of the biggest insects seem to have changed together, Clapham says. With falling oxygen, wingspans shrank. Upticks in oxygen corresponded with bigger wings. But then around 100 million to 150 million years ago, “the two seem to go in opposite directions.”

What happened? Birds first emerged at that time, Clapham says. There were now more flying creatures. Birds could prey on insects and potentially compete with them for food, he notes.

Even when oxygen levels were high, not all insects were huge. Bees, which appeared about 100 million years ago, have stayed roughly the same size. Ecology probably explains this, Clapham says. “Bees have to pollinate flowers. And if flowers are not getting any bigger, then bees can’t really get any bigger.”

The unicorns in the new movie Onward may look like the beauties that adorn fanciful clothing and school supplies. But don’t be fooled by their silvery white color and shimmery horns. These gussied-up ponies act like dumpster-diving raccoons while snarling at residents. They roam the streets of Mushroomton, a town populated by magical creatures.

The unicorns popular today typically aren’t garbage-eating pests. But they often have a similar look: white horses with heads that have sprouted a single spiraling horn. While everyone knows that these unicorns are just a flight of fancy, is there any chance they could ever exist?

The short answer: It’s highly unlikely. But scientists have ideas about how these animals could become real. A bigger question, though, is whether it would be a good idea to make one.

The long road to a unicorn

A unicorn doesn’t look that much different from a white horse. And getting a white horse is pretty easy. One mutation on a single gene turns an animal into an albino. These animals don’t make the pigment melanin. Albino horses have white bodies and manes and light eyes. But this mutation can also mess with other processes inside the body. In some animals, it can lead to poor vision or even blindness. So unicorns that evolved from albino horses might not be all that healthy.

A horn or rainbow coloring are more complex traits. They tend to involve more than one gene. “We can’t say ‘we are going to change this gene and now we’re going to have a horn,’” says Alisa Vershinina. She studies the DNA of ancient horses at the University of California, Santa Cruz.

If any of these traits were to evolve, they would need to give a unicorn some advantage that helps it survive or reproduce. A horn, for instance, might help a unicorn defend itself against predators. Colorful features might help a male unicorn attract a mate. That’s why many birds have bright and bold colors. “Maybe horses would be able develop these crazy colors … that would favor boys that are very beautiful pink and purple,” Vershinina says.

But none of this would happen fast because horses (and the resulting unicorns) have relatively long lifespans and reproduce slowly. Evolution “doesn’t work in a snap,” Vershinina notes.

Sure, the new Aquaman movie has big toothy sea monsters. It’s got glowing tridents and a hero who can lift an entire submarine. But it’s the city of Atlantis that really steals the show. Named after the mythical metropolis that collapsed into the ocean, Atlantis here is an entire underwater kingdom. Whales swim by glowing, disk-shaped buildings. These newer structures rise above old ruins, stacking up like a huge coral reef made of condos.

It’s enough to make anyone wish for life under the sea. But while that underwater life looks peaceful, it comes with a lot of pressure. (And not just because you might be fighting for your life against your half-brother and his attempts to take over the world.) All that water weighs heavy upon a person, fish or Atlantean building. And that requires some special adaptations to survive.

Above water, you — and everything on the planet — are under a bit of pressure. Air has mass, and that mass presses down. At sea level, the column of air above you presses down with a force of about 1 kilogram per square centimeter (14.5 pounds per square inch). That is about the weight of a 3-month-old baby on every square inch. It might sound heavy, but you don’t notice it because your body is used to this pressure.

Climb to the top of a mountain and there will be less air above you. That reduced mass means there is less pressure. But dive into the ocean, sink down, and you’ll quickly discover what real pressure is.

Pushing down on me, pushing down on you

Water is heavier than air. The farther you sink below the surface, the more water that weighs down on you. Every 10 meters (or 33 feet) of depth adds another 6.6 kilograms per square centimeter (14.5 pounds per square inch) of pressure.

“If you took an empty plastic water bottle and went down 75 feet [22 meters], it would be crushed flat,” notes George Elvin. He works at North Carolina State University in Raleigh. There, he studies how people can build structures in extreme environments — underwater, for instance.

People are a bit tougher than empty plastic water bottles, of course. But they’re not indestructible. “The deepest human dive unprotected is about 1,000 feet,” Elvin says. That’s about 300 meters. At this depth, the body is experiencing 100 times the pressure it experiences at the surface. At deeper depths, Elvin explains, there’s so much pressure that any sack of air in your body — such as your lungs — would simply collapse. If your lungs don’t expand, you don’t breathe. Nice knowing you.

This is the Aquarius Reef Base, sitting pretty under the sea. Scientists use it to study life underwater in the Gulf of Mexico.

CREDIT: COURTESY OF FLORIDA INTERNATIONAL UNIVERSITY

Most people live on dry ground, but there are a few who live underwater for short periods — well within those tolerable limits. Even then, though, they require time to adjust, notes Roger Garcia. He’s the operations director of the Aquarius Reef Base. It’s an underwater habitat where scientists can live for a few days at a time while they study the ocean. It sits 15 meters (about 50 feet) below the surface of the Gulf of Mexico, off the western coast of Florida.

The inside of this facility is filled with air kept at the same pressure as the water outside. At that depth, Garcia says, it doesn’t really feel like the water is pressing in on all sides, and he’s got plenty of experience with it. There’s only one thing he notices. Because the gas is denser than at sea level, he notes, “most of the time your voice is a little bit deeper.” So hanging out in a shallow Atlantis would affect your singing voice, but that’s about it.

Returning to the surface, however, isn’t easy — even from such shallow depths. As someone swims to the surface, the pressure drops. This allows gases dissolved in the body to form bubbles. If those bubbles form in the blood or brain, they can cause joint aches. They can even burst vessels in the brain and rupture tissues in the lungs. This condition is known as decompression sickness (or sometimes, “the bends”).

Astronaut Roy McBride peers out over the Earth at the start of the new sci-fi flick Ad Astra. It’s not an unusual view for him. He does mechanical work atop an international space antenna. This spindly structure stretches up toward the stars. But this day, McBride’s sweet view is interrupted by an explosion that hurtles him off the antenna. He plummets from the blackness of space toward Earth until his parachute opens, slowing his descent.

In the movie, the space antenna looks like pipes stacked upon pipes that reach into space. But could anyone build something that tall? And can people actually climb up from Earth into space?

A tall order

There’s no set line between Earth and space. Where space begins depends on whom you ask. But most scientists agree that space starts somewhere between 80 and 100 kilometers (50 and 62 miles) above Earth’s surface.

Building a skinny tower that tall isn’t possible. Anyone who’s stacked up a tower of Legos knows that at some point the structure won’t be sturdy enough to hold its own weight. It eventually tilts to the side, before crashing and scattering its bricks. A better strategy is to build something like a pyramid that narrows as it grows in height.

The idea of using long ribbons in space has been around for a while. In 1992, this tethered satellite system was sent out from the space shuttle Atlantis. The shuttle successfully dragged the system around, but it didn’t reach its full potential. The cable was supposed to be 20 kilometers (12.5 miles), but it hit a snag when deploying and only 256 meters (840 feet) were released. CREDIT: TSS-1/STS-46 Crew/NASA

But even if we could build a tower that tall, there’d be problems, says Markus Landgraf. He’s a physicist at the European Space Agency. He’s based in Noordwijk, the Netherlands. A tower that could reach space would be too heavy for the Earth to support, he says. Earth’s crust isn’t very deep. It averages only around 30 kilometers (17 miles). And the mantle below is a bit squishy. The tower’s mass would push too hard on the Earth’s surface. “It would basically create a ditch,” Landgraf says. And, he adds, “It would keep doing so over thousands of years. It would go deeper and deeper. It would not be pretty.”

It’s frog dissection day in biology class in the new film The Addams Family. Wednesday Addams thinks she knows what to do. First, she leaps on the table. Then, raising her hands to the sky, she shouts, “Give my creature life!” A device that pulses with electricity now shocks a dead frog waiting to be cut open by the kids’ scalpels. The electricity then bounces from one frog to another. Suddenly, frogs are hopping everywhere — a bit groggy at first, but apparently as alive as ever.

This wild scene isn’t one you’ll be able to recreate on dissection day in your own science class. Electricity can’t jolt the dead back to life. Still, this scene has a lot in common with experiments that happened hundreds of years ago. Back then, scientists were learning how electricity kicks muscles into motion.

Today’s researchers know that electricity can do a lot of amazing things — including help shape the body in the first place.

Muscle powerhouse

Skeletal muscles help animals move and breathe. These muscles move because of tension in their fibers. This is called “contraction.” Muscle contractions are triggered by signals that start in the brain. The electrical signals travel down the spinal cord and to the nerves that reach into muscle.

But electric impulses also can come from outside the body. “If you’ve ever shocked yourself on something, your muscles contracted,” explains Melissa Bates. A physiologist at the University of Iowa in Iowa City, she studies how bodies work. Bates focuses on the diaphragm. That’s a muscle that helps mammals breathe.

Shocking a dead frog might make its muscles twitch and get its legs to wiggle. Still, this animal couldn’t hop away, Bates points out. That’s because leg muscles can’t make their own electrical signals.

As soon as a frog hopped away from the source of electricity, the game would be up, she says. “It would fall down and be limp and not able to move.” (This applies to the muscles in a hand, too. And that has left Bates wondering how Thing — a hand without a body — can move at all.)

There are some muscles in the body that can power themselves. Involuntary muscles, such as the heart and muscles that move food through the intestines, supply their own electric impulses. In an animal that has recently died, these muscles continue to function for a while. They can keep contracting for minutes to upwards of an hour, Bates says. But that won’t help the frog make a getaway.

It is possible to use electricity to revive people when they are having a heart attack. For this, people use machines called defibrillators (De-FIB-rill-ay-tors). This isn’t reanimating the dead, though. Defibrillators only work “in something that appears lifeless but still has some of its own electrical potential to reboot that system,” Bates explains. Electricity helps get heartbeats back to a regular rhythm. But this won’t work if the heart has stopped beating entirely (which happens when it has lost its ability to make electrical impulses).

The frogs from biology lab have probably been dead for quite a while and preserved with chemicals. They couldn’t be revived with a defibrillator because they wouldn’t have any heart electrical activity left to jump start.

Twitch, twitch

Wednesday Addams’ froggy antics, while impossible, call to mind experiments that scientists did in the late 1700s. “That was the first hint that electricity is an important part of our body,” says Bates. Back then, people were just starting to see what electricity could do. Some shocked dead animals to figure out how electricity made muscles move.  

The most famous of these experimenters was Luigi Galvani. He worked as a doctor and physicist in Italy.

Galvani mostly worked with dead frogs, or rather their bottom halves. He would slice open the frog to reveal the nerves that ran from the spinal cord to a leg. Then, to study how a frog’s muscles respond to electricity, Galvani would wire up the frog’s leg under different conditions.

Italian scientist Luigi Galvani studied electricity in the body by wiring up frogs’ leg muscles in different ways. This image illustrates his experiments connecting nerves to leg muscles, which then contracted. CREDIT: Wellcome Collection (CC BY 4.0)

By this time, scientists already knew that an electric shock would make muscles twitch. But Galvani had questions about how and why that happened. For example, he wondered if lightning would do the same thing as the electricity made by his machine. So he hooked up one animal to a wire that snaked outside to a thunderstorm. He then watched those frog legs dance when they were jolted by lightning — just as they did with his machine’s electricity.

Elephants can’t fly. Unless, of course, the elephant in question is Dumbo. In the cartoon and the new, computer-enhanced live version of the tale, a baby elephant is born with enormous ears — even for an elephant. Those ears help him fly and soar to stardom in the circus. But could an African elephant — even a small one like Dumbo — ever take to the skies? Well, science shows, the elephant would have to get smaller. A lot smaller.

Elephant ears are not just useless flaps, notes Caitlin O’Connell-Rodwell. At Stanford University in California, she studies how elephants communicate. First, of course, an elephant’s ear is for listening. “When they’re listening, they hold their ears out and scan,” O’Connell-Rodwell says. Fanning and curving their big ears makes a shape rather like a satellite dish. That helps the elephants pick up sounds over very long distances.

Elephant ears are worth 1,000 words. It’s pretty clear that this elephant wants the giraffe gone.  CREDIT: O’Connell & Rodwell/The Elephant Scientist

The ears can send signals too, O’Connell-Rodwell notes. “You’d think these giant floppy things are sitting there,” she says. “But [elephants] do have a lot of dexterity in their ears, and they use that as a communication aid.” Different ear motions and poses tell other elephants (and scientists) about an elephant’s mood.

Elephant ears take up a lot of real estate. That’s especially true for African elephants, which have ears much larger than their Asian elephant relatives. An African elephant’s ears are around 1.8 meters (6 feet) from top to bottom (that’s taller than the average height of an adult man). The huge, floppy appendages are full of blood vessels. This helps an elephant stay cool. “They fan their ears back and forth,” O’Connell-Rodwell explains. This “moves more blood in and out of the ears and dissipates the [body] heat.”

But can they fly?