13 Scientific Explanations for Everyday Life

iStock
iStock

Science holds our lives together. It explains everything from why bread rises to why you need gas to power your car. In his book Atoms Under the Floorboards, author Chris Woodford lays out the abstract science that underlies the everyday world, from the big (how do skyscrapers stay up?) to the small (why does my laptop get hot when I’m watching Netflix?). Along the way, he also calculates the answers to whimsical questions like, “How many people would I have to gather together to keep my house warm without heat?” (A lot, but not as many as you'd think.) Here are 13 things we learned about the world through his eyes.

1. A POWER DRILL COULD SET YOUR HOUSE ON FIRE, IN THEORY.

Because of friction, electric drills generate heat. The motor, the drill bit, and the wall all get hot. It takes about 2000 joules of energy to heat one kilogram of wood just 1°C. Assuming a typical power drill uses 750 watts of electricity, and it puts out 750 joules of energy, Woodford calculates that it would take just four minutes to set fire to a wooden wall in a 68°F room.

2. STICKY NOTES COME OFF EASILY BECAUSE THEIR ADHESIVE IS UNEVEN.

Post-it Notes feature a plastic adhesive that is spread out in blobs across the paper. When you slap a Post-it onto your bulletin board, only some of these blobs (technically called micro-capsules) touch the surface to keep the note stuck there. Thus, you can unstick it, and when you go to attach it to something else, the unused blobs of glue can take over the adhesive role. Eventually, all the capsules of glue will get used up or clogged with dirt, and the sticky note won't stick anymore.

3. GUM IS CHEWY BECAUSE IT'S MADE OF RUBBER.

Early gums got their elastic texture from chicle, a natural type of latex rubber. Now, your bubble gum is made with synthetic rubbers like styrene butadiene (also used in car tires) or polyvinyl acetate (also used in Elmer’s glue) to mimic the effect of chicle.

4. OFFICE BUILDINGS ARE EVER-SO-SLIGHTLY TALLER AT NIGHT.

After all the employees go home, tall office buildings get just a little taller. A 1300-foot-tall skyscraper shrinks about 1.5 millimeters under the weight of 50,000 occupants (assuming they weigh about the human average).

5. A LEGO BRICK CAN SUPPORT 770 POUNDS OF FORCE.

LEGOs can support four to five times the weight of a human without collapsing. They are strong enough to support a tower 375,000 bricks tall, or around 2.2 miles high.

6. POLISHING SHOES IS LIKE FILLING IN A ROAD'S POTHOLES.

Regular leather appears dull to the eye because it’s covered in teeny-tiny scrapes and scratches that scatter whatever light hits the material. When you polish a leather shoe, you coat it in a fine layer of wax, filling in those crevices much like a road crew smoothes out a street by filling in its potholes. Because the surface is more uniform, rays of light bounce back toward your eye more evenly, making it look shiny.

7. YOU COULD HEAT YOUR HOUSE WITH JUST 70 PEOPLE.

People give off body heat, as anyone who has been trapped in a small crowded room knows. So how many people would it take to warm up your home with just body heat in the winter? About 70 people in motion, or 140 people still, figuring that humans radiate 100-200 watts of heat normally and that the house uses four electric storage heaters.

8. DENSITY EXPLAINS WHY COLD WATER FEELS COLDER THAN AIR AT THE SAME TEMPERATURE.

Because water is denser than air, your body loses heat 25 times more quickly while in water than it would in air at the same temperature. Water's density gives it a high specific heat capacity, meaning it takes a lot of heat to raise its temperature even a little, and it's very good at retaining heat or cold (the reason why hot soup stays hot for a long time, and why the ocean is much cooler than land). Water is a great conductor, so it's very effective at transferring that heat or cold to your body.

9. WATER CLEANS WELL BECAUSE IT HAS ASYMMETRICAL MOLECULES.

Because water molecules are triangular—made of two hydrogen atoms stuck to one oxygen atom—they have slightly different charges on their different sides, kind of like a magnet. The hydrogen end of the molecule is slightly positive, and the oxygen side is slightly negative. This makes water excellent at sticking to other molecules. When you wash away dirt, the water molecules stick to the dirt and pull it away from whatever surface it was on. This is also the reason water has surface tension: it’s great at sticking to itself.

10. THE "PULSE" SETTING ON A BLENDER WORKS BETTER BECAUSE OF TURBULENCE.

When your blender stops chopping up food and begins just spinning it around in circles, it’s because everything inside is spinning at the same rate. Instead of actually blending ingredients together, it’s experiencing laminar flow—all the layers of liquid are moving in the same direction with constant motion. The pulse function on the blender introduces turbulence, so instead of the fruit chunks rolling around the side of the blender, they fall into the center and get blended up into a smoothie.

11. BABIES' BODIES CONTAIN MORE WATER THAN ADULTS.'

Adults are around 60 percent water. By contrast, newborn babies are about 80 percent water. But that percentage quickly drops: A year after birth, kids' water content is down to around 65 percent, according to the USGS.

12. GLASS BREAKS EASILY BECAUSE ITS ATOMS ARE LOOSELY ARRANGED.

Unlike other solid materials, like metals, glass is made up of amorphous, loosely packed atoms arranged randomly. They can’t absorb or dissipate energy from something like a bullet. The atoms can’t rearrange themselves quickly to retain the glass’s structure, so it collapses, shattering fragments everywhere.

13. CALORIE COUNTS ARE CALCULATED BY INCINERATING FOOD.

Calorie values on nutritional labels estimate the energy contained in the food within the package. To figure out how much energy is in a specific food, scientists use a calorimeter. One type of calorimeter essentially burns up the food inside a device surrounded by water. By measuring how much the temperature of the water changes in the process, scientists can determine how much energy was contained in the food.

This story originally ran in 2015.

Bizarre New Giant Salamander Species Discovered in Florida

There’s something in the water in Florida, but it’s not the swamp monster locals may have feared. According to National Geographic, scientists have discovered a new species of giant salamander called a reticulated siren, and you can find the 2-foot-long amphibian in the swamps of southern Alabama and the Florida panhandle.

Locals have long reported seeing a creature with leopard-like spots, the body of an humongous eel, and axolotl-like frills sprouting out of the sides of its head, but its existence wasn’t described in scientific literature until now. Researchers from Texas and Georgia recently published their findings in the journalPLOS ONE.

“It was basically this mythical beast,” David Steen, a wildlife ecologist and one of the paper’s co-authors, tells National Geographic. He had been trapping turtles at the Eglin Air Force Base in Okaloosa County, Florida, in 2009 when he caught one of the creatures by chance. After that encounter, the researchers set out to find more specimens.

Colloquially, locals have long been calling the creature a leopard eel. Because the reticulated siren only has two tiny front limbs, it's easy to mistake it for an eel. Its hind limbs disappeared throughout the course of millions of years of evolution, and it also lacks eyelids and has a beak instead of the teeth that are typical of other salamander species.

They belong to a genus of salamanders called sirens, which are one of the largest types of salamander in the world. The second part of the species’ name comes from the reticulated pattern seen on all of the individuals that were examined by researchers. The reticulated siren is also one of the largest vertebrates to be formally described by scientists in the U.S. in the last 100 years, according to the paper.

There are still a lot of unknowns about the reticulated siren. They lead hidden lives below the surface of the water, and they’re thought to subsist on insects and mollusks. Researchers say further study is urgently needed because there's a chance the species could be endangered.

[h/t National Geographic]

A Dracula Ant's Jaws Snap at 200 Mph—Making It the Fastest Animal Appendage on the Planet

Ant Lab, YouTube
Ant Lab, YouTube

As if Florida’s “skull-collecting” ants weren’t terrifying enough, we’re now going to be having nightmares about Dracula ants. A new study in the journal Royal Society Open Science reveals that a species of Dracula ant (Mystrium camillae), which is found in Australia and Southeast Asia, can snap its jaws shut at speeds of 90 meters per second—or the rough equivalent of 200 mph. This makes their jaws the fastest part of any animal on the planet, researchers said in a statement.

These findings come from a team of three researchers that includes Adrian Smith, who has also studied the gruesome ways that the skull-collecting ants (Formica archboldi) dismember trap-jaw ants, which were previously considered to be the fastest ants on record. But with jaw speeds of just over 100 miles per hour, they’re no match for this Dracula ant. (Fun fact: The Dracula ant subfamily is named after their habit of drinking the blood of their young through a process called "nondestructive cannibalism." Yikes.)

Senior author Andrew Suarez, of the University of Illinois, said the anatomy of this Dracula ant’s jaw is unusual. Instead of closing their jaws from an open position, which is what trap-jaw ants do, they use a spring-loading technique. The ants “press the tips of their mandibles together to build potential energy that is released when one mandible slides across the other, similar to a human finger snap,” researchers write.

They use this maneuver to smack other arthropods or push them away. Once they’re stunned, they can be dragged back to the Dracula ant’s nest, where the unlucky victims will be fed to Dracula ant larvae, Suarez said.

Researchers used X-ray imaging to observe the ants’ anatomy in three dimensions. High-speed cameras were also used to record their jaws snapping at remarkable speeds, which measure 5000 times faster than the blink of a human eye. Check out the ants in slow-motion in the video below.

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