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.

10 Citizen Science Projects That Need Your Help

A citizen scientist takes a photo of scarlet mushrooms.
A citizen scientist takes a photo of scarlet mushrooms.
lovelypeace/iStock via Getty Images

Channel your inner Nikola Tesla or Marie Curie by participating in actual scientific research, either out and about or without even leaving your couch. These projects unleash the power of the public to be places that researchers can’t be and to spread the workload when data start piling up. They really can’t do it without you.

1. Catalog photos of Earth's cities at night.

Photo from space of a city at night
Identify cities from the photos taken from the International Space Station.
Chris Hadfield, NASA // Public Domain

Cities at Night—a study by Complutense University of Madrid—asks people to catalog images of the Earth at night taken from the International Space Station, part of the millions of images in the Gateway to Astronaut Photography of Earth database. The current project, Lost at Night, needs people to identify cities within images of 310-mile circles on Earth. Hundreds of volunteers have classified thousands of images already, but classification by multiple individuals ensures greater accuracy. In fact, the project will determine the optimum number of people needed. The primary goal is an open atlas of publicly available nighttime images. Just log on to the image database to help.

2. Follow fish using high-tech tags.

You’ll have to go fishing—an outdoor activity you can do by yourself!—for this assignment. Volunteer to tag fish for the American Littoral Society, whose citizen scientists have tagged more than 640,000 fish since the program began in 1965. You can tag the fish you catch and release, or report tagged fish to the organization. The data is sent to the National Marine Fisheries Service Laboratory in Woods Hole, Massachusetts, where it helps scientists track the populations and movements of coastal species like striped bass, flounder, and bluefish. To get started, become a member of the American Littoral Society, which comes with a packet of tagging gear and instructions.

3. Spy on penguins in Antarctica.

Penguins on an ice floe
Keeping tabs on penguins is one way a citizen scientist can lend a hand.
axily/iStock via Getty Images

Here's another project for those stuck indoors. Penguins are threatened by climate change, fisheries, and direct human disturbance, yet scientists have little data on the birds. To fill in the gaps, 50 cameras throughout the Southern Ocean and Antarctic Peninsula take images of colonies of gentoo, chinstrap, Adélie, and king penguins year-round. You can help the University of Oxford-based research team by sorting through thousands of images to identify and mark individual adult penguins, chicks, and eggs. You'll be pinpointing seasonal and geographic variations in populations that may represent changes to the Antarctic ecosystem. Marking other animals in the images helps researchers figure out which ones are hanging around penguin colonies. Discuss a specific image or the project with the science team and other volunteers in an online forum.

4. Battle an invasive marine species.

Like to dive or snorkel? Make it count by reporting lionfish sightings or captures to the Reef Environmental Education Foundation's Volunteer Reef Survey Project. Lionfish, which are native to the Indo-Pacific, were first sighted in the South Atlantic in 1985 and were likely released by private aquarium owners. Since then, they have spread throughout the Caribbean and Gulf of Mexico and caused native fish populations to decline by up to 80 percent. Scientists say this invasion may be one of the century’s greatest threats to warm temperate and tropical Atlantic reefs. You can also join a lionfish derby to catch and kill some of the tasty fish so scientists can analyze their biology.

5. Count birds from your backyard.

Bluebirds at a bird feeder
Bluebirds dine on mealworms at a bird feeder.
MelodyanneM/iStock via Getty Images

North American birds are in trouble. Recent studies predict dramatic declines in the populations of migratory birds due to climate change—and much of the data that went into these studies came from citizen scientists who monitored species without leaving home. The Cornell Lab of Ornithology and Birds Canada launches Project FeederWatch in the winter months; you simply put out a bird feeder and report the number and species of birds that visit it. Citizen scientists can also join the Cornell Lab's NestWatch—you find a nest, monitor it every three or four days, and report your data. And every February, the Audubon Society runs the Great Backyard Bird Count, in which participants submit data to produce a real-time snapshot of bird populations across North America. Any time of the year, birdwatchers can submit lists of the birds they see on eBird, a huge database of sightings that informs public policy, conservation efforts, and other initiatives.

6. Photograph plants for climate change research.

The Appalachian Mountain Club's Mountain Watch program asks hikers to document alpine and forest plants for ecological research. By taking photos of flowers and fruiting plants along woodland trails and uploading them to the iNaturalist app, participants provide data about the times and places that plants bloom. Scientists then compile the information in an online database and analyze it for trends that could indicate changing climates.

7. Comb through ships' logbooks for weather data.

Old handwritten letters
Practice your handwriting-deciphering skills on the Old Weather project.
scisettialfio/iStock via Getty Images

Ships’ logs from mid-19th century American sailing vessels contain detailed weather observations. Citizen scientists can help transcribe observations from whaling vessels for the Old Weather project; scientists will use the information to learn more about past environmental conditions and create better climate models for future projections. Historians will also use the data to track past ship movements and tell the stories of the people on board.

8. Make American history documents and science notes accessible to more people.

The Smithsonian Libraries are stuffed with original history and science documents that have lain in drawers for decades. Help open up "America's attic" to the public by organizing and transcribing digital versions of handwritten field notebooks, diaries, logbooks, specimen labels, photo albums, and other materials. You'll join thousands of other volunteers to investigate documents like the Sally K. Ride Papers, the collection of the Freedmen's Bureau (which helped former slaves following the Civil War), and field studies of insects by the Irish naturalist Arthur Stelfox.

9. Investigate historical crimes in Australia.

Drawing of a convict ship to Australia
A drawing of a 19th-century convict ship destined for Australia.
Photos.com/iStock via Getty Images

If you're obsessed with true crime, you'll love this project. Volunteer to investigate and transcribe criminal records from 19th- and 20th-century Australia, which was founded as a British penal colony. Alana Piper, a postdoctoral research fellow at the Australian Centre for Public History at the University of Technology Sydney, will use the transcriptions to construct the "life histories and offending patterns of Australian criminals" from the 1850s to the 1940s. More than 40,000 subjects have been completed so far.

10. Map the unique features of Mars's South Pole.

Travel to Mars—without the hassle of zero gravity or space-vegetable farming—through Planet Four, a citizen science project that is currently tasked with identifying features on Mars's dynamic South Pole. Volunteers examine photos from the HiRISE camera on NASA's Mars Reconaissance Orbiter and pick out "fans" or "blotches" in the landscape of seasonal carbon dioxide ice. Scientists believe these structures indicate wind speed and direction on the Martian surface and offers clues about the evolution of the Red Planet's climate.

Why Cats Like to Shove Their Butts in Your Face, According to an Animal Behavior Expert

This cat might be happier showing off its butt.
This cat might be happier showing off its butt.
Okssi68/iStock via Getty Images

Cats are full of eccentric behaviors. They hate getting wet. Their tongues sometimes get stuck midway out of their mouths, known as a “blep.” And they’re really happy hanging out in bodegas.

Some of these traits can be explained while others are more mysterious. Case in point: when they stick their rear end in your face for no apparent reason.

Are cats doing this just to humiliate their hapless caregivers? What would possess a cat to greet a person with its butt? Why subject the person who gives you food and shelter to such degradation?

To find out, Inverse spoke with Mikel Delgado, a postdoctoral fellow at the School of Veterinary Medicine at UC Davis. According to Delgado, cats don’t necessarily perceive their rectal flaunting as anything aggressive or domineering. In fact, it might be a cat’s way of saying hello.

“For cats, it’s normal for them to sniff each other’s butts as a way to say hello or confirm another cat’s identity,” Delgado said. “It’s hard for us to relate to, but for them, smell is much more important to cats and how they recognize each other than vision is. So cats may be ‘inviting’ us to check them out, or just giving us a friendly hello.”

For a cat, presenting or inspecting a butt is a kind of fingerprint scan. It’s a biological measure of security.

Other experts agree with this assessment, explaining that cats use their rear end to express friendliness or affection. Raising their tail so you can take a whiff is a sign of trust. If they keep their tail down, it’s possible they might be feeling a little shy.

If you think this situation is eased by the fact you rarely hear cats fart, we have bad news. They do. Because they don’t often gulp air while eating, they just don’t have enough air in their digestive tract to make an audible noise. Rest assured that, statistically speaking, there will be times a cat giving you a friendly greeting is also stealthily farting in your face.

[h/t Inverse]

SECTIONS

arrow
LIVE SMARTER