15 of the Longest-Running Scientific Studies in History

Most experiments are designed to be done quickly. Get data, analyze data, publish data, move on. But the universe doesn’t work on nice brief timescales. For some things you need time. Lots of time.

1. THE BROADBALK EXPERIMENT // 173 YEARS

In 1842, John Bennet Lawes patented his method for making superphosphate (a common, synthetic plant nutrient) and opened up what is believed to be the first artificial fertilizer factory in the world. The following year, Lawes and chemist Joseph Henry Gilbert began a series of experiments comparing the effects of organic and inorganic fertilizers, which are now the oldest agricultural studies on Earth. For over 150 years parts of a field of winter wheat have received either manure, artificial fertilizer, or no fertilizer. The results are about what you’d expect: artificial and natural fertilized plots produce around six to seven tons of grain per hectare, while the unfertilized plot produces around one ton of grain per hectare. But there’s more. They can use these studies to test everything from herbicides to soil microbes and even figure out oxygen ratios for better reconstruction of paleoclimates.

2. THE PARK GRASS EXPERIMENT // 160 YEARS

Lawes and Gilbert started several more experiments at around the same time. In one of these experiments with hay, Lawes observed that each plot was so distinct that it looked like he was experimenting with different seed mixes as opposed to different fertilizers. The nitrogen fertilizers being applied benefited the grasses over any other plant species, but if phosphorus and potassium were the main components of the fertilizer, the peas took over the plot. Since then, this field has been one of the most important biodiversity experiments on Earth.

3. THE BROADBALK AND GEESCROFT WILDERNESSES // 134 YEARS

Yet another one of Lawes’ experiments: In 1882 he abandoned part of the Broadbalk experiment to see what would happen. What happened was that within a few years, the wheat plants were completely outcompeted by weeds—and then trees moved in [PDF]. In 1900, half of the area was allowed to continue as normal and the other half has had the trees removed every year in one of the longest studies of how plants recolonize farmland.

4. DR. BEAL’S SEED VIABILITY EXPERIMENT // 137 YEARS

In 1879, William Beal of Michigan State University buried 20 bottles of seeds on campus. The purpose of this experiment was to see how long the seeds would remain viable buried underground. Originally, one bottle was dug up every five years, but that soon changed to once every 10 years, and is now once every 20 years. In the last recovery in 2000, 26 plants were germinated, meaning slightly more than half survived over 100 years in the ground. The next will be dug up in 2020, and (assuming no more extensions) the experiment will end in 2100.

Even if it is extended for a while, there will probably still be viable seeds. In 2008, scientists were able to successfully germinate a circa-2000 year old date palm seed, and four years later, Russian scientists were able grow a plant from a 32,000 year old seed that had been buried by an ancient squirrel.

5. THE PITCH DROP EXPERIMENT // 86 YEARS

If you hit a mass of pitch (the leftovers from distilling crude oil) with a hammer, it shatters like a solid. In 1927, Thomas Parnell of the University of Queensland in Australia decided to demonstrate to his students that it was actually liquid. They just needed to watch it for a while. Some pitch was heated up and poured into a sealed stem glass funnel. Three years later, the stem of the funnel was cut and the pitch began to flow. Very slowly. Eight years later, the first drop fell. Soon the experiment was relegated to a cupboard to collect dust, until 1961 when John Mainstone learned of its existence and restored the test to its rightful glory. Sadly, he never saw a pitch drop. In 1979 it dropped on a weekend, in 1988 he was away getting a drink, in 2000 the webcam failed, and he died before the most recent drop in April 2014.

As it turns out, the Parnell-initiated pitch drop experiment isn’t even the oldest. After it gathered international headlines, reports of other pitch drop experiments became news. Aberystwyth University in Wales found a pitch drop experiment that was started 13 years before the Australian one, and has yet to produce a single drop (and indeed is not expected to for another 1300 years), while the Royal Scottish Museum in Edinburgh found a pitch drop experiment from 1902. All of them prove one thing though: With enough time, a substance that can be shattered with a hammer still might be a liquid.

6. THE CLARENDON DRY PILE // 176-191 YEARS

Around 1840, Oxford physics professor Robert Walker bought a curious little contraption from a pair of London instrument makers that was made up of two dry piles (a type of battery) connected to bells with a metal sphere hanging in between them. When the ball hit one of the bells, it became negatively charged and shot towards the other positively charged bell where the process repeats itself. Because it uses only a minuscule amount of energy, the operation has occurred ten billion times and counting. It’s entirely possible that the ball or bells will wear out before the batteries fully discharge.

Although we don’t know the composition of the battery itself (and likely won’t until it winds down in a few hundred years), it has led to scientific advancements. During WWII, the British Admiralty developed an infrared telescope that needed a battery capable of producing high voltage, low current, and that could last forever. One of the scientists remembered seeing the Clarendon Dry Pile—also referred to as the Oxford Electric Bell—and was able to find out how to make his own dry pile for the telescope.

7. THE BEVERLY (ATMOSPHERIC) CLOCK // 152 YEARS

Sitting in the foyer of the University of Otago in New Zealand is the Beverly Clock. Developed in 1864 by Arthur Beverly, it is a phenomenal example of a self-winding clock. Beverly realized that, while most clocks used a weight falling to get the energy to run the clock mechanism, he could get the same energy with one cubic foot of air expanding and contracting over a six-degree Celsius temperature range. It hasn’t always worked; there have been times it needed cleanings, it stopped when the Physics department moved, and if the temperature is too stable it can stop. But it’s still going over 150 years later.

8. THE AUDUBON CHRISTMAS BIRD COUNT // 116 YEARS

Since 1900, folks from across the continent have spent time counting birds. What began as an activity to keep people from hunting our feathered friends on Christmas Day, has turned into one of the world’s most massive and long-lasting citizen science projects. Although the 2015 results aren’t ready yet, we know that in 2014, 72,653 observers counted 68,753,007 birds of 2106 species.

9. THE HARVARD STUDY OF ADULT DEVELOPMENT // 78 YEARS

One of the longest running development studies, in 1938 Harvard began studying a group of 268 sophomores (including one John F. Kennedy), and soon an additional study added 456 inner-city Bostonians. They’ve been followed ever since, from World War II through the Cold War and into the present day, with surveys every two years and physical examinations every five. Because of the sheer wealth of data, they’ve been able to learn all kinds of interesting and unexpected things. One such example: The quality of vacations one has in their youth often indicates increased happiness later in life.

10. THE TERMAN LIFE CYCLE STUDY // 95 YEARS

In 1921, 1470 California children who scored over 135 on an IQ test began a relationship that would turn into one of the world’s most famous longitudinal studies—the Terman Life Cycle Study of Children with High Ability.  Over the years, in order to show that early promise didn’t lead to later disappointment, participants filled out questionnaires about everything from early development, interests, and health to relationships and personality.  One of the most interesting findings is that, even among these smart folk, character traits like perseverance made the most difference in career success.

11. THE NATIONAL FOOD SURVEY // 76 YEARS

Starting in 1940, the UK’s National Food Survey tracked household food consumption and expenditure, and was the longest lasting program of its kind in the world. In 2000 it was replaced with the Expenditure and Food Survey, and in 2008 the Living Costs and Food Survey. And it’s provided interesting results. For instance, earlier this year it was revealed that tea consumption has fallen from around 23 cups per person per week to only eight cups, and no one in the UK ate pizza in 1974, but now the average Brit eats 75 grams (2.5 ounces) a week.

12. THE FRAMINGHAM HEART STUDY // 68 YEARS

In 1948, the National Heart, Lung, and Blood Institute teamed up with Boston University to get 5209 people from the town of Framingham to do a long-term study of how cardiovascular disease developed. Twenty-three years later they also recruited the adult children of the original experiment and in 2002 a third generation. Over the decades, the Framingham Heart Study researchers claim to have discovered that cigarette smoking increased risk, in addition to identifying potential risk factors for Alzheimer’s, and the dangers of high blood pressure.

13. THE E. COLI LONG TERM EVOLUTION EXPERIMENT // 26 YEARS

While this one might not seem that impressive in terms of length, it has to be the record for number of generations that have come and gone over the course of the study: well over 50,000. Richard Lenski was curious whether flasks of identical bacteria would change in the same way over time, or if the groups would diverge from each other. Eventually, he got bored with the experiment, but his colleagues convinced him to keep going, and it’s a good thing they did. In 2003, Lenski noticed that one of flasks had gone cloudy, and some research led him to discover that the E. coli in one of the flasks had gained the ability to metabolize citrate. Because he had been freezing previous generations of his experiment, he was able to precisely track how this evolution occurred.

14. THE BSE EXPERIMENT // 11 YEARS

Sadly, sometimes things can go terribly wrong during long-term experiments. Between 1990 and 1992, British scientists collected thousands of sheep brains. Then, for over four years, those prepared sheep brains were injected into hundreds of mice to learn if the sheep brains were infected with BSE (mad-cow disease). Preliminary findings suggested that they were, and plans were drawn up to slaughter every sheep in England. Except those sheep brains? They were actually cow brains that had been mislabeled. And thus ended the longest running experiment on sheep and BSE.

15. THE JUNEAU ICEFIELD RESEARCH PROGRAM // 68 YEARS

Attention to glacier retreat and the effects of global warming on the world’s ice fields has rapidly increased over the course of the last few decades, but the Juneau Icefield Research Program has been monitoring the situation up north since 1948. In its nearly 70 years of existence, the project become the longest-running study of its kind, as well as an educational and exploratory experience. The monitoring of the many glaciers of the Juneau Icefield in Alaska and British Columbia has a rapidly approaching end date though—at least in geological terms. A recent study published in the Journal of Glaciology predicts that the field will be gone by 2200.

Mapping Technology Reveals 'Lost Cities' on National Geographic

Lin uses his iPad to visualize scanning data of a crusaders' fortress at the lagoon in Acre, Israel.
Lin uses his iPad to visualize scanning data of a crusaders' fortress at the lagoon in Acre, Israel.
Blakeway Productions/National Geographic

Imagine what Pompeii looked like before the lava hit, or Mayan pyramids before the jungle took over. In the past decade, scientists have been able to explore human settlements long since abandoned by using a new wave of accessible technology. Instead of needing an expensive plane and crew to fly aerial sensors, for example, explorers can mount them on cheaper drones and pilot them into previously unreachable areas. The resulting data can tell us more about the past, and the future, than ever before.

That’s the premise of Lost Cities with Albert Lin, a new TV series premiering on National Geographic on Sunday, October 20.

Lin, an engineer and National Geographic Explorer, uses cutting-edge tools to shed light on centuries-old cities in the most beautiful places on Earth. Ground-penetrating radar reveals buried structures without disturbing the landscape. A drone-mounted remote sensing method called LIDAR—short for "Light Detection and Ranging"—shoots lasers at objects to generate data, which Lin visualizes with 3D mapping software. The results suggest what the ruins probably looked like when they were new.

Albert Lin and crew in Peru
Thomas Hardy, Adan Choqque Arce, Joseph Steel, Duncan Lees, Albert Lin, and Alonso Arroyo launch the LIDAR drone at Wat'a in Peru.
National Geographic

“It’s like a window into a world that we’ve never had before,” Lin tells Mental Floss. “It’s shooting millions of laser pulses per second through a distance of air. By digitally removing the top layer of everything above the ground—trees, brush, cacti—you’re washing away the past. All of the sudden you’re left with these fingerprints—experiments in how we organized ourselves through time.”

For the six-episode series, Lin and the expert storytelling team were dispatched to the South Pacific, the Middle East, the Andes, the Arctic, and other destinations. Lin explains that while most of the sites are known to archaeologists, they’ve never been so precisely mapped in three-dimensional detail.

In the first episode, Lin travels to Nan Madol, an enigmatic complex of temples and other structures on the Micronesian island of Pohnpei. With the help of local researchers and indigenous leaders, Lin and the team scan the ruins and digitally erase trees, water, and forest undergrowth to unveil the complex's former grandeur.

“Technology and innovation have always been that gateway to go beyond the threshold, and see what’s around the corner,” Lin says. “Seeing these worlds for the first time since they were left, it’s almost like reversing the burning of the library of Alexandria. We can take the synthesis of knowledge of all these watershed moments of our human journey, and imagine a better future.”

Lost Cities With Albert Lin premieres Sunday, October 20 at 10/9c and resumes on Monday, October 21 at 10/9c on National Geographic.

8 Ways Science Can Boost Your Halloween Fun

iStock
iStock

Halloween is all about embracing the supernatural, but science shouldn't entirely fall by the wayside during the spookiest of holidays. Here are a few ways it can actually improve your holiday, from making trick-or-treating easier to fooling your brain into thinking you're eating tasty treats even though you're nibbling on candy cast-offs.

1. Slow the decomposition of your Halloween jack-o'-lantern.

A Halloween display of five jack-o-lanterns
iStock

You don't have to be an expert gardener to keep your jack-o'-lantern looking fresh all Halloween season long. While scouting out pumpkins, pick hard, unblemished ones and steer clear of those with watery dark spots. These splotches indicate frost damage.

Hold off on carving until right before Halloween so your gourds won't rot—but if you can't resist, try squirting their exteriors with lemon juice after you're done slicing and dicing. The acid inhibits pumpkin enzymes, which react with oxygen and cause browning. A light misting of bleach solution will help keep fungus at bay. Some apply vegetable oil or Vaseline to prevent shriveling and drying. We experimented with various techniques in this video.

For extra TLC, you might even want to bring your jack-o'-lanterns in at night if temperatures dip; if you live in a hot and humid area, extend its life by placing it in the fridge overnight. Try using glow sticks or LED lights instead of flesh-singeing candles.

2. Use apps to plan a treat-or-treating route.

Three children in Halloween costumes trick-or-treating
iStock

Thanks to technology, trick-or-treaters (and their hungry adult companions) can now scout out which neighbors are doling out the best candy and which are sticking with Tootsie Rolls, apples, and toothbrushes. Simply download the app for Nextdoor, the neighborhood-based social network, to check out an interactive "treat map" that lets users tag whether their home is handing out treats, and what that treat is.

Since safety is far more important than sugar, guardians should also consider adding a tracking app to their arsenal come Halloween, especially if their kid's venturing out alone. The Find My Family, Friends, Phone app gives the real-time locations of trick-or-treaters, provides alerts for when they turn home, and also comes with a "panic" button that provides emergency contact details when pressed.

3. Optimize your candy's flavor (even if it's SweeTarts).

Hard candies and gummies strewn across a table
iStock

Not crazy about this year's Halloween loot? Fool yourself into thinking those black licorice pieces and peanut chews taste better than they actually do by eating them after you scarf down the chocolate and Sour Patch Kids. According to a 2012 study published in Psychological Science, being aware that these items of candy are your very last candies actually tricks the brain into appreciating them more (and thus thinking they're tastier than they really are).

Meanwhile, a 2013 study from the same journal found that creating a candy-eating ritual enhances flavor and overall satisfaction. Nibble the ridged edges off a Reese's peanut butter cup before tackling the creamy center, sort the M&Ms by color, and take your time unwrapping a chocolate bar.

4. Create a DIY fog machine with carbon.

Dry ice in a glass bowl
iStock

Save money at Party City by creating your own fog machine at home. When dropped in water, dry ice—or frozen carbon dioxide—creates a gas that's a combination of carbon dioxide and water vapor, but looks like the fog you'd see rolling through a haunted graveyard [PDF].

5. Eat sort-of-heart-healthy Halloween candy.

A stack of dark chocolate chunks on a dark stone background
iStock

Halloween candy isn't always bad for you. While shopping for this year's trick-or-treat bounty, steer clear of sugary confections and milk chocolate mini-bars. Opt for dark chocolate treats instead. Research suggests that our gut microbes ferment the antioxidants and fiber in cocoa, creating heart-healthy anti-inflammatory compounds. Plus, dark chocolate or cocoa also appears to help lower blood pressure for people with hypertension, decrease bad cholesterol, and stave off cardiovascular disease and diabetes, among other benefits.

6. Analyze data on Halloween candy trends and give the people what they want.

Lollipops
5second/iStock via Getty Images

Thanks to data science, you can make sure you're giving out the best treats on the block. Bulk candy retailer CandyStore.com combed through 10 years of data (2007 to 2016, with a particular focus on the months leading up to Halloween) to gauge America's top-selling sweets. They created an interactive map to display their results, which includes the top three most popular Halloween handouts in each state and Washington, D.C. Be prepared for plenty of stoop-side visitors and adorable photo ops.

7. Bake better Halloween treats with chemistry.

Frosted Halloween cookies shaped like ghosts and pumpkins
iStock

Cooking is essentially chemistry—and depending on your technique, you can whip up chewy, fluffy, or decadent Halloween treats according to taste.

Folding chunks of chilled butter into your dough will give you thick, cake-like cookies, as will swapping baking soda for baking powder. When butter melts, its water converts into gas, which leaves lots of tiny holes. If the butter flecks in question are colder and larger, they'll leave bigger air pockets. As for the baking powder, it produces carbon dioxide gas both when it's mixed into the dough and when it's heated. For an extra boost in texture, you can also try adding more flour.

Prefer chewier cookies? Start out with melted butter in the dough, and stick with plain old baking soda.

And for extra-fragrant and flavorful baked goods, opt to use dark sugars—like molasses, honey, and brown sugar—because they're filled with glucose and fructose instead of plain old sucrose. As cookies bake, they undergo two processes: caramelization, in which the sugar crystals liquefy into a brown soup; and the Maillard reaction, a chemical reaction between the dough's proteins and amino acids (flour, egg, etc.) and the reducing sugars that causes tasty browning.

8. Take deep breaths to stay calm in haunted houses.

A brown-haired woman in a red polka dot blouse standing with a frightened expression next to a spider web.
iStock

Halloween can be tough for people with anxiety or low thresholds for fear. While visiting a haunted house or watching a scary movie, remember to take deep breaths, which fends off the body's flight-or-fight response, and reframe your anxiety in your mind as "excitement." It's also a good idea to schedule spine-chilling activities after an activity that triggers feel-good endorphins—say, after a walk to check out your neighbors' awesome Halloween displays.

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