For some, cooking is an art. For others, a hobby. But for a considerable number of people, cooking is a daily obstacle that must be overcome in order to satiate hunger. But whether you’re new to the kitchen or know a stovetop like the back of your hand, there are some food questions that just have to be asked. From understanding chemical reactions to testing food myths, here are a few things that every cook in the kitchen should know.
Is the “Five-Second Rule” Real?
Most people know the “five-second rule”: the idea that if food that’s fallen on the floor has been there less than five seconds, it’s still acceptable to eat. No one knows the origins of this questionable rule — and plenty of people think it’s kind of gross — but that hasn't stopped anyone from picking up a dropped Oreo and shouting "five-second rule!" before.
Though its origins may be murky, actual scientists have devoted time and resources to testing the five-second rule. And surprisingly, it’s not an entirely bogus theory — depending on the cleanliness of the floor.
To be clear, no scientist has gone on record recommending that you eat dropped food. However, a science experiment conducted at the University of Illinois Urbana-Champaign proved that as long as the food was picked up within the five-second time limit, the presence of microorganisms on the dropped food was minimal. However, the experiment was conducted after first sanitizing the flooring, and it only applied to hard flooring like tile and wood, which are less likely to serve as an incubator for pathogens. No testing was conducted on carpeting and other soft surfaces, which can hold moisture and become breeding grounds for bacteria.
Let’s cut to the chase: It’s definitely not recommended to blindly follow the five-second rule. You have no way of knowing which pathogens are on your floor, so unless you regularly disinfect, it’s best to play it safe. According to the experts, dry foods are slightly safer than wet ones because moisture is a great medium for pathogens to attach themselves. So, a potato chip or cracker might acquire a minimal pathogen transfer whereas an apple or slice of banana might test positive for a higher pathogen count. But we recommend a new rule: When in doubt, throw it out.
Why Do You Cry When You Cut Onions?
There’s no need to cry over spilled milk, but what about chopped onions? You can thank a chemical combination of enzymes and sulfur for the tears that well up while you make dinner.
Onions use sulfur to make a mixture of amino acids and enzymes during the growing process. The acids and enzymes are separated and stored in different regions of the onion’s cells, which are called vacuoles. While the onion remains whole, the amino acids and enzymes in the onion’s cells remain separated. Once you cut into the onion, however, everything mixes together. When the two substances are combined, they form a chemical known as syn-Propanethial-S-oxide, or lachrymatory factor (LF). LF is an irritant that’s easily vaporized when it reacts with the air.
LF isn’t strong enough to affect tougher parts of your body such as your skin, but it can irritate more sensitive regions. As the vapors waft up toward your face, your eyes will begin to sting. Your body — sensing the irritant — will release a torrent of tears in an attempt to wash the chemicals from your eyes. Luckily, LF can’t do any serious damage, even in high quantities.
Producing LF is the onion’s way of defending against anything that may want to eat it. As soon as an animal bites into the root, its eyes start to burn and it’s reminded to stay away from onions.
Unfortunately for onions, humans are persistent.
How Do Taste Buds Work?
Taste buds are the reason we pucker our lips when we suck on a lemon wedge or smile when savor a piece of chocolate. They're how we can identify our favorite foods. In fact, without taste buds we wouldn’t be able to sense the five basic tastes: salty, sweet, sour, bitter, and umami. But what exactly are taste buds and how do they work?
Every tongue is covered in visible bumps known as papillae that fall into four categories: filiform, fungiform, circumvallate, and foliate. Each papillae type except for filiform carries a number of taste buds that are continuously being replaced. In total, every tongue has an average of 10,000 taste buds, which are replaced about every two weeks.
Despite what some may believe, there are no specific areas of the tongue responsible for a particular taste. Instead, it’s the taste receptors scattered across your tongue that pinpoint the proper flavor.
The taste buds in your different papillae are simply a combination of basal cells, columnar (structural) cells, and receptor cells. Different types of receptor cells are coated with proteins intended to attract specific chemicals that are linked to one of the five basic tastes. When the receptor cell identifies the chemical it binds with, it will send a signal through a neural network to the brain via microvilli, or microscopic hairs on every taste bud.
There is more to taste than just the tongue, however. Lining the uppermost part of the human nose are olfactory receptors that are responsible for smell, and they send messages that further hone in on specific tastes. When you chew food, a chemical is released that travels to the upper part of your nose and activates the olfactory receptor. These receptors work in conjunction with the receptors on taste buds to help the brain recognize the taste. This helps explain why a cold or allergies can hinder one’s sense of taste, making everything taste bland.
Does Tryptophan Really Make You Tired?
Anyone who's passed out after indulging in a Thanksgiving feast knows the theory: tryptophan, an amino acid found in turkey, makes you sleepy. But is this conventional wisdom actually true?
The short answer is … not exactly. L-tryptophan, as it's officially known, can also be found in everything from chicken and yogurt to fish and cheese, none of which are typically associated with sleepiness. Once ingested, tryptophan is converted into the B-vitamin niacin, which helps create the neurotransmitter serotonin. Serotonin plays a key role in melatonin levels and sleep itself, hence the apparent causal link between turkey and fatigue.
Plenty of other amino acids are present in turkey, however, and most of them are found in greater abundance — meaning that, when all those chemicals are rushing to your brain after your second helping, tryptophan rarely wins the race.
If, however, the tryptophan gets a little assistance in the form of carbohydrates, it gets a better shot at dominating your system. Eating carbs — which abound in Thanksgiving dishes like mashed potatoes and stuffing — produces insulin, which flushes every amino acid except tryptophan from your bloodstream. Thus, your post-Thanksgiving sleepiness is actually the result of a perfect storm composed of tryptophan, carbs, and the large portions typically associated with the holiday.
What Are Superfoods?
While many nutritionists and physicians recommend healthy eating over fad diets, some foods offer more nutritional benefits than others. That’s why, in recent years, you might have heard about “superfoods” and why you should incorporate them into your diet.
The term “superfood” doesn’t come from medical science. Instead, it was designed by marketers at food companies to help boost sales. But in general, the term applies to particular foods that are nutrient-rich and provide significant health benefits when consumed regularly.
One example of a superfood are eggs, which feature two powerful antioxidants: lutein and zeaxanthin. They are also low in calories, averaging 77 calories per egg. And most importantly, they’re full of nutrients such as iron, phosphorous, selenium, and a myriad of vitamins including A, B2, B5, and B12.
There are also a variety of fruits and vegetables that qualify as superfoods, including berries. Berries are rich in antioxidants, high in fiber, and contain a wide array of vitamins, particularly Vitamins C and K1, manganese, copper, and folate. But nutrient levels can vary widely between berries. For example, strawberries have the highest vitamin C levels of the superfood berries. This heart-healthy food can also help lower inflammation and improve blood sugar and insulin response.
While the phrase “superfoods” might not have a hard definition, there’s plenty of evidence to show that certain foods can improve your health and reduce your risk of serious conditions such as cancer, high blood pressure, and heart disease.
From castles, cathedrals, and palaces to miles-long bridges, golden temples, and sky-scraping glass towers, the world is full of magnificent feats of architectural engineering. While the purpose of most of these structures is known, there are still plenty of human-made monuments that boggle the minds of even the most acclaimed scientists and archaeologists. Here are 11 such monuments that remain a mystery.
Original photo by Stephanie LeBlanc/ Unsplash
Carnac Stones (France)
The Carnac Stones are a group of more than 3,000 megalithic standing stones in the French village of Carnac, Brittany. These stones date back to the Neolithic period and were probably erected between 3300 and 4500 BCE. They are one of the world’s largest collections of menhirs — upright stones arranged by humans. There is no real evidence to confirm their purpose, but that hasn’t stopped researchers from hazarding guesses. Some theorize they were used as calendars and observatories by farmers and priests. According to Christian mythology, the stones are pagan soldiers who were petrified by Pope Cornelius. Local folklore, meanwhile, says that the stones stand in straight lines because they were once part of a Roman army. The story goes on to say that the Arthurian wizard Merlin turned the Romans to stone.
Easter Island Moai (Chile)
Over 2,000 miles off the coast of Chile, Easter Island (Isla de Pascua) is the one-time home of a Polynesian people called the Rapa Nui. Scattered across the island are around 1,000 moai, giant hand-carved stone statues of human-like figures that are half-buried in the earth. The Rapa Nui landed on the island sometime between 700 and 800 CE, and are believed to have started making the moai around 1100 CE. Each moai weighs 14 tons and stands 13 feet tall on average, so it’s hard to imagine how they were transported and hauled into place. One theory is that the islanders used a system of ropes and tree trunks. Their purpose has also been the subject of much debate. To the Rapa Nui, the statues may have stored sacred spirits.
Nazca Lines (Peru)
Southern Peru’s Nazca Desert is covered with hundreds of geometric designs. These ancient geoglyphs range from simple shapes to plants and animals such as a hummingbird, monkey, llama, and whale. The Nazca Lines date back to around 200 to 700 CE, when the Nazca people who lived in the region created them. Researchers have struggled to agree upon the purpose of these giant works of art, particularly since they are best seen from the surrounding hills and by plane. Among many theories are astronomical maps, indicators of sacred routes, and water troughs. An alternative take is that they were created to be observed by deities from the sky.
Stone Spheres (Costa Rica)
In Costa Rica’s Diquis Delta is a group of around 300 polished stone spheres, some just a few inches in diameter and others measuring up to seven feet and weighing 16 tons. Employees of the United Fruit Company stumbled across the spheres in the 1930s while clearing a jungle to build a banana plantation. Scientists have so far been unable to pinpoint an exact date of their origin, instead suggesting that they appeared sometime between 200 BCE and the 16th century CE. They are commonly attributed to the Diquis people, yet their purpose is a mystery. They might have been property markers of ancient chiefs, and some even think they may be remnants of the lost city of Atlantis. Some of the spheres were even detonated in the hope of finding gold inside.
Temple of Bacchus (Lebanon)
The Baalbek temple complex in northeast Lebanon is one of the most intriguing Roman ruins on the planet. Its centerpiece is the well-preserved and monumental Temple of Bacchus. The age of the temple is unknown, although it was most likely erected in the second century CE. Most historians agree that emperor Antoninus Pius commissioned it in honor of Bacchus, the god of wine and intoxication. What has been baffling archaeologists ever since the temple’s rediscovery in the late 19th century is how the Romans succeeded in building it. It is staggering to think that humans without heavy machinery could hoist the 42 Corinthian columns (19 of which remain standing) of the colonnade, since each stands 62 feet tall and 7.5 feet in diameter.
Hagar Qim (Malta)
Located on the Mediterranean island of Malta, the UNESCO World Heritage Site of Hagar Qim is one of seven prehistoric temples in Malta and is believed to date to between 3800 BCE and 2200 BCE. The site’s name translates to “standing stones,” and one of the largest weighs in at more than 20 tons, measuring nearly 23 feet in height. The site was first excavated in 1839 and consists of a series of rooms lined by these megaliths. Parts of the chamber align with the sunrise and sunset of the summer solstice. This and the other temples on the island all appear to have been built in the same period, which has left archaeologists puzzled — there is little evidence of any civilization capable of such building feats on the islands at that time.
Göbekli Tepe (Turkey)
Could a set of ruins in southeastern Turkey be remnants of the world’s first temple? That’s one of the key questions archaeologists ponder as they explore Göbleki Tepe, a series of huge stone pillars that are some 6,000 years older than Stonehenge. Now a UNESCO World Heritage Site, the landmark was ignored for centuries, dismissed as little more than a cemetery. In the mid-1990s, excavations began and experts soon realized it was a treasure trove of history. The pillars weigh as much as 10 tons each and create massive stone circles. Radar surveys of the area indicate a number of additional circles are still buried underground. Göbleki Tepe is older than writing and older than agriculture. But who were the Neolithic people who built this, and how and why did they do it?
Yonaguni Monument (Japan)
Experts are divided as to whether the underwater rocks near Japan’s Yonaguni Island are a human-made structure or naturally occurring. In the 1980s, divers discovered what appears to be a rectangular monument, measuring 165 feet long and 65 feet wide. Some scholars believe that it is the remains of a pyramid, perhaps from a long-lost submerged city belonging to an ancient civilization. Meanwhile, others insist the rocks have been shaped by millennia of the ocean’s currents. Similarly, while some argue that markings on the rock’s surface are proof of ancient human involvement, others say they are simply scratches. For the time being, the Japanese government seems to agree with the latter and does not recognize the Yonaguni Monument as culturally significant.
Great Zimbabwe Ruins (Zimbabwe)
The Great Zimbabwe Ruins are the largest ruins in sub-Saharan Africa. This medieval city was once a trading hub and possibly the capital of the Queen of Sheba’s realm. The remains consist of the Great Enclosure (perhaps a royal residence), the Hill Complex (possibly the religious heart of the city), and the Valley Ruins (houses which suggest the city once had a population of 20,000 people). In total, the Great Zimbabwe Ruins extend across an area of 200 acres. The city is thought to have been abandoned in the 15th century, for reasons scientists aren’t sure of.
The Maya people of what is now Mexico were incredibly advanced when it came to writing, building, and knowledge of astronomy. Yet scientists still know little about other parts of their culture. By the time Spanish conquistadors arrived from Europe, the Maya civilization had already fallen, and historians still debate the cause. Some of the finest Maya ruins are at Palenque, in the Mexican state of Chiapas, an elaborate complex that includes a palace and several temples. Thought to have been constructed between 500 and 700 CE, it features plaster carvings and decorations that are still remarkably well-preserved. The city at Palenque is a marvel of design but remains shrouded in mystery since we may never know why it was abandoned around 900 CE.
No list of mysterious sites would be complete without the Neolithic monument at Stonehenge, which is known worldwide and continues to mystify visitors. The enormous stones are estimated to have been placed between 2500 BCE and 2200 BCE. Hundreds of even older burial mounds have also been uncovered in the surrounding area. Some of the stones come from several hundred miles away in Wales, leading archaeologists to speculate how they were transported. Others are from nearer parts of Wiltshire. What was Stonehenge’s purpose? Many believe it was a spiritual site, and people still flock to it as the sun rises on the summer solstice, when sunlight rises above the Heel stone at Stonehenge and falls directly onto the middle of the circle.