13 Scientific Explanations for Everyday Life

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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.

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.

14 Facts About Celiac Disease

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iStock.com/fcafotodigital

Going gluten-free may be a modern diet trend, but people have been suffering from celiac disease—a chronic condition characterized by gluten intolerance—for centuries. Patients with celiac are ill-equipped to digest products made from certain grains containing gluten; wheat is the most common. In the short-term this can cause gastrointestinal distress, and in the long-term it can foster symptoms associated with early death.

Celiac diagnoses are more common than ever, which also means awareness of how to live with the condition is at an all-time high. Here are some things you might not know about celiac disease symptoms and treatments.

1. Celiac an autoimmune disease.

The bodies of people with celiac have a hostile reaction to gluten. When the protein moves through the digestive tract, the immune system responds by attacking the small intestine, causing inflammation that damages the lining of the organ. As this continues over time, the small intestine has trouble absorbing nutrients from other foods, which can lead to additional complications like anemia and osteoporosis.

2. You can get celiac disease from your parents.

Nearly all cases of celiac disease arise from certain variants of the genes HLA-DQA1 and HLA-DQB1. These genes help produce proteins in the body that allow the immune system to identify potentially dangerous foreign substances. Normally the immune system wouldn't label gliadin, a segment of the gluten protein, a threat, but due to mutations in these genes, the bodies of people with celiac treat gliadin as a hostile invader.

Because it's a genetic disorder, people with a first-degree relative (a sibling, parent, or child) with celiac have a 4 to 15 percent chance of having it themselves. And while almost all patients with celiac have these specific HLA-DQA1 and HLA-DQB1 variations, not everyone with the mutations will develop celiac. About 30 percent of the population has these gene variants, and only 3 percent of that group goes on to develop celiac disease.

3. Makeup might contribute to celiac disease symptoms.

People with celiac disease can’t properly process gluten, the protein naturally found in the grains like wheat, rye, and barley. Patients have to follow strict dietary guidelines and avoid most bread, pasta, and cereal, in order to manage their symptoms. But gluten isn’t limited to food products: It can also be found in some cosmetics. While makeup containing gluten causes no issues for many people with celiac, it can provoke rashes in others or lead to more problems if ingested. For those folks, gluten-free makeup is an option.

4. The name comes from 1st-century Greece.

A 1st-century Greek physician named Aretaeus of Cappadocia may have been the first person to describe celiac disease symptoms in writing [PDF]. He named it koiliakos after the Greek word koelia for abdomen, and he referred to people with the condition as coeliacs. In his description he wrote, “If the stomach be irretentive of the food and if it pass through undigested and crude, and nothing ascends into the body, we call such persons coeliacs.”

5. There are nearly 300 celiac disease symptoms.

Celiac disease may start in the gut, but it can be felt throughout the whole body. In children, the condition usually manifests as bloating, diarrhea, and abdominal discomfort, but as patients get older they start to experience more “non-classical” symptoms like anemia, arthritis, and fatigue. There are at least 281 symptoms associated with celiac disease, many of which overlap with other conditions and make celiac hard to diagnose. Other common symptoms of the disease include tooth discoloration, anxiety and depression, loss of fertility, and liver disorders. Celiac patients also have a greater chance of developing an additional autoimmune disorder, with the risk increasing the later in life the initial condition is diagnosed.

6. Some patients show no symptoms at all.

It’s not uncommon for celiac disease to be wrecking a patient’s digestive tract while showing no apparent symptoms. This form of the condition, sometimes called asymptomatic or “silent celiac disease,” likely contributes to part of the large number of people with celiac who are undiagnosed. People who are at high risk for the disease (the children of celiac sufferers, for example), or who have related conditions like type 1 diabetes and Down syndrome (both conditions that put patients at a greater risk for developing new autoimmune diseases) are encouraged to get tested for it even if they aren’t showing any signs.

7. It’s not the same as wheat sensitivity.

Celiac is often confused with wheat sensitivity, a separate condition that shares many symptoms with celiac, including gastrointestinal issues, depression, and fatigue. It’s often called gluten sensitivity or gluten intolerance, but because doctors still aren’t sure if gluten is the cause, many refer to it as non-celiac wheat sensitivity. There’s no test for it, but patients are often treated with the same gluten-free diet that’s prescribed to celiac patients.

8. It's not a wheat allergy either.

Celiac disease is often associated with wheat because it's one of the more common products containing gluten. While it's true that people with celiac can't eat wheat, the condition isn't a wheat allergy. Rather than reacting to the wheat, patients react to a specific protein that's found in the grain as well as others.

9. It can develop at any age.

Just because you don’t have celiac now doesn’t mean you’re in the clear for life: The disease can develop at any age, even in people who have tested negative for it previously. There are, however, two stages of life when symptoms are most likely to appear: early childhood (8 to 12 months) and middle adulthood (ages 40 to 60). People already genetically predisposed to celiac become more susceptible to it when the composition of their intestinal bacteria changes as they get older, either as a result of infection, surgery, antibiotics, or stress.

10. Not all grains are off-limits.

A gluten-free diet isn’t necessarily a grain-free diet. While it’s true that the popular grains wheat, barley, and rye contain gluten, there are plenty of grains and seeds that don’t and are safe for people with celiac to eat. These include quinoa, millet, amaranth, buckwheat, sorghum, and rice. Oats are also naturally gluten-free, but they're often contaminated with gluten during processing, so consumers with celiac should be cautious when buying them.

11. Celiac disease can be detected with a blood test.

Screenings for celiac disease used to be an involved process, with doctors monitoring patients’ reactions to their gluten-free diet over time. Today all it takes is a simple test to determine whether someone has celiac. People with the condition will have anti-tissue transglutaminase antibodies in their bloodstream. If a blood test confirms the presence of these proteins in a patient, doctors will then take a biopsy of their intestine to confirm the root cause.

12. The gluten-free diet doesn’t work for all patients.

Avoiding gluten is the most effective way to manage celiac disease, but the treatment doesn’t work 100 percent of the time. In up to a fifth of patients, the damaged intestinal lining does not recover even a year after switching to a gluten-free diet. Most cases of non-responsive celiac disease can be explained by people not following the diet closely enough, or by having other conditions like irritable bowel syndrome, lactose intolerance, or small intestine bacterial overgrowth that impede recovery. Just a small fraction of celiac disease sufferers don’t respond to a strict gluten-free diet and have no related conditions. These patients are usually prescribed steroids and immunosuppressants as alternative treatments.

13. If you don’t have celiac, gluten probably won’t hurt you.

The gluten-free diet trend has exploded in popularity in recent years, and most people who follow it have no medical reason to do so. Going gluten-free has been purported to do everything from help you lose weight to treat autism—but according to doctors, there’s no science behind these claims. Avoiding gluten may help some people feel better and more energetic because it forces them to cut heavily processed junk foods out of their diet. In such cases it’s the sugar and carbs that are making people feel sluggish—not the gluten protein. If you don’t have celiac or a gluten sensitivity, most experts recommend saving yourself the trouble by eating healthier in general rather than abstaining from gluten.

14. The numbers are growing.

A 2009 study found that four times as many people have celiac today than in the 1950s, and the spike can’t be explained by increased awareness alone. Researchers tested blood collected at the Warren Air Force Base between 1948 and 1954 and compared them to fresh samples from candidates living in one Minnesota county. The results supported the theory that celiac has become more prevalent in the last half-century. While experts aren’t exactly sure why the condition is more common today, it may have something to do with changes in how wheat is handled or the spread of gluten into medications and processed foods.

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