‘A study showed…’ isn’t enough – scientific knowledge builds incrementally as researchers investigate and revisit questions

Why one study is never enough.

Good Partner

May 4, 2026

By Good Partner

May 4, 2026

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Photo credit: Jacob Wackerhausen/iStock via Getty Images Plus – When you hear about some new research finding, consider how it fits into the context of other related studies.

Jeffrey A. Lee

Your goofy but lovable cousin just told you that you should stop eating eggs because he read somewhere that a study showed they are bad for you.

How much should you trust your relative on such matters? More importantly, how much should you rely on one newly published bit of research when deciding what to make for breakfast?

To be clear, this is not an article about the health-promoting or health-torpedoing properties of eggs. It’s about how scientific knowledge is built piece by piece from many studies. What scientists know is refined over time as new results either do or don’t point to the same conclusion.

I’m a geographer who’s been doing and teaching science for many decades, with a sideline of teaching and writing about how science is done. Many people, quite understandably, take a single experiment or study as the be-all and end-all of knowledge because that’s how research often is presented by the press or on social media. But the better way to approach new research is to find how it weaves together with other work on the topic to create big-picture understanding.

Painting of18th C man in fancy dress standing by telescope and looking up at Moon in sky — Science evolves over time as more data and discoveries refine scientific knowledge. Historica Graphica Collection/Heritage Images via Getty Images

How science works

Most research studies are undertaken either to fill a gap in our knowledge or to test an existing theory to see whether it deserves the confidence people have in it. After identifying the topic, scientists design a study to achieve those ends. They may run an experiment to learn more about how a chemical affects certain cells, for instance, or collect data in the field to track a natural phenomenon, such as how water temperatures affect hurricanes.

Then the researchers submit their findings to a peer-reviewed journal, where other experts – the scientists’ peers – decide whether it’s quality research deserving of publication.

Not all journals have rigorous peer review. Papers are highly unreliable if published by “paper mills” – journals that appear scholarly but will publish anything if the authors pay a fee.

Peer review doesn’t guarantee that the conclusions are valid, but it increases the chances that they are. Individual papers might be wrong because of honest mistakes, such as unforeseen limitations in the experimental design or, rarely, from outright fraud.

No scientific paper solves a problem once and for all. Neither does it negate all previous research. Well-done research contributes a bit to the scientific community’s understanding of a topic. The next, and crucial, step is putting individual studies in context with other research on the topic.

Even if there is current consensus, a new study may reveal a weakness, and that could lead to more research to figure out what is more likely to be correct. Scientific knowledge is constantly being refined as new information comes to light.

Adding more evidence bit by bit

One question to ask as you consider a particular finding is whether it has been directly replicated, meaning other researchers repeated the experiment to see whether they got the same results. Unfortunately, replication is relatively rare in science; more common are similar studies using comparable data, different methods, or both.

Your confidence can grow when scientists have performed a bunch of related research that’s gone through peer review, been published in scholarly journals and mostly points in the same direction. Of course, if they don’t agree, then your confidence should be weaker.

Sometimes researchers may compile these comparisons in what’s called a systematic review. They may use statistical techniques to perform meta-analysis on data from many different studies at once. Generally speaking, the more good data used to test an idea, the better.

An additional issue is how many studies have been done on a topic. There are thousands of studies on the causes of lung cancer, but there may be only one or two on how a couple of particular genes affect hair loss. Scientists’ confidence in what is known about lung cancer, then, is far greater than what is known about how those genes may have contributed to my baldness.

Appreciating the strength of the evidence is as important as understanding the evidence itself.

Get a helping hand

The idea of expertise has fallen out of favor in some quarters. But experts are vital when it comes to understanding scientific issues. An expert in this sense is someone who has been immersed in the topic for years, knows how to evaluate the relevant studies, and, ideally, has done research on it.

With such a background, an expert is a good judge of how likely any one study is to be wrong. Equally important, they also must try to control the all-too-human impulse to accept what they like and reject what they don’t.

Unfortunately, most people rarely have direct access to experts. The next best thing is someone educated in the general topic – verifiably educated, not someone who browses the internet for a few hours.

Woman writing on the board while teaching a class to a group of people in white coats — Healthcare professionals keep up with the scientific literature in their field so they can provide evidence-based, up-to-date care to patients. Hispanolistic/E+ via Getty Images

Healthcare professionals who have years of training, clinical experience and requirements to keep up with the literature in their field can help you make good decisions based on new medical research. But be careful. You want to rely on someone who updates their recommendations as the state of scientific knowledge evolves, but not someone who latches onto every new outlandish discovery.

In practice, some healthcare practitioners – hopefully a small minority – are not trustworthy on such matters. If someone is selling you something that sounds too good to be true, assume that it is. They may even have a financial or personal stake in their recommendation.

Consider the source

You should retain some skepticism about what you read in the popular press and even more about what you see on social media.

A good journalist who knows how to assess new studies can act as a guide and help you understand scientific issues. You’re looking for journalists who can accurately and objectively report on new research and help put it in context with what else is known. Unfortunately, there is no list of good versus bad journalists, but general guidance is available, such as that from nonprofit journalism organization The Trust Project.

Journalists who are well versed in how science works can also help you spot whether there are any conflicts of interest at play. Was that study that encourages staying energetic by eating a pound of candy a day sponsored by a snack food company? That would be a major red flag.

I’m not saying that everyone needs to do a thorough literature review before speaking about a scientific issue or deciding whether to eat eggs a couple of times a week. But I do encourage you to adopt a little humility about what you know and understand, along with a realistic appreciation for the limits of both your own knowledge and what the scientific community understands.

And definitely don’t make life-altering decisions based on an article describing one scientific study, even if your cousin tells you to.

This article originally appeared on The Conversation. You can read it here.

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Photo credit: RM Bulseco/Flickr, CC BY – Millions of people fly safely every day, but when plane crashes do happen, they can be catastrophic.

Science, Technology

Compared to driving, flying is extraordinarily safe – but why doesn’t it feel that way?

Why the safest way to travel can feel like the riskiest

Good Partner

9/14/2026

Mihhail Berezovski

Alex Chaparro

A commercial airplane crash can change how people behave long after the immediate tragedy. News outlets replay the images, people affected share their harrowing stories, and an extraordinarily rare event becomes easy to imagine. Some travelers cancel trips; others drive to their destination instead.

These choices may feel cautious. Statistically, the alternatives people switch to may come with greater risk.

Commercial airline crashes command attention because they are rare, catastrophic and beyond a passenger’s control. But the choice to avoid flying does not eliminate risk. As a new report from our research team at Embry-Riddle Aeronautical University outlines, skipping a flight and opting to drive instead is typically much riskier, even if it doesn’t feel like it.

Airline travel is safer than headlines suggest

People tend to respond strongly to events that are vivid, while paying less attention to familiar hazards – the risks of which manifest more frequently but less visibly. As a result, efforts to avoid one danger can create another.

In our recent peer-reviewed report, prepared with support from Embry-Riddle Aeronautical University’s Boeing Center for Aviation and Aerospace Safety, we compared fatality risk in U.S. commercial aviation with other transportation modes, recreational activities, household hazards and occupational risks. While the Boeing Center receives some funding from The Boeing Company, it operates independently.

We focused on commercial Part 121 airlines operating in the U.S. and analyzed data from 2016 through 2025. Part 121 carriers generally include large U.S. airlines and regional carriers that operate scheduled passenger service. Because fatal accidents are so rare, data from a single year would not have provided a stable risk estimate.

Across several measures of risk exposure, including distance traveled, individual boardings, hours spent traveling, annual risk and lifetime odds, the data consistently shows that U.S. commercial aviation is exceptionally safe.

For the same distance traveled, we estimated the fatality risk as about 626 times higher in a passenger car or truck than on a commercial airline. The risk associated with motorcycle travel was more than 22,000 times higher than commercial airline travel. Even highway bus travel, itself a relatively safe option, carried about nine times the risk of commercial airline travel over the same distance.

When risk is measured per passenger boarding, the numbers remain striking. From 2016 through 2024, the long-run estimate was approximately one passenger fatality per 97.7 million boardings on commercial airlines.

These numbers do not mean flying is risk-free, just that the risk is small enough that researchers need many years and enormous amounts of exposure to estimate it. Across the 10-year study period, 73 people died in accidents involving commercial airline travel in the United States.

These findings complement earlier research. A peer-reviewed 2013 study comparing U.S. transportation modes examined data from 2000 through 2009 and also identified commercial aviation as the safest way to travel. A 2018 study using data from the same period similarly ranked commercial aviation as the safest mode.

More recently, a 2022 study analyzed U.S. news coverage, travel patterns and accident data from 1996 through 2017. It found that increased news coverage of aviation accidents was associated with more road traffic and more fatal road accidents in subsequent months.

The 9/11 aftermath and the risk of avoiding risk

The aftermath of the Sept. 11, 2001, terrorist attacks provided a powerful example of how behavior can shift risk from one setting to another. Air travel declined sharply after the 9/11 attacks. Subsequently, researchers were able to investigate whether fear of flying led to additional deaths on the road.

Psychologist Gerd Gigerenzer analyzed traffic patterns for the final three months of 2001 and estimated 353 excess road deaths nationwide. He characterized many people’s decision to drive rather than fly as an attempt to avoid a “dread risk”: a low-probability event in which many people could die at once.

After a high-profile plane crash, road traffic can increase. AP Photo/LM Otero, File

Transportation researchers Michael Sivak and Michael Flannagan later reanalyzed the period. They used road fatality trends from the first eight months of 2000 and 2001 to estimate how many deaths would normally have occurred during the final three months of 2001. They then compared that estimate with the number actually recorded in the past three months and calculated 1,018 additional road fatalities from October 2001 through December 2001.

But their findings complicated the idea that people who avoided flying merely drove to the same distant destinations. Much of the increase occurred on local roads, not interstate highways, and pedestrians and bicyclists experienced a disproportionate share of fatalities. This pattern suggests that travel behavior may have changed more broadly after the attacks, perhaps because people canceled longer trips, stayed closer to home or changed their daily routines.

It is hard to pin down how much of this increase was related to people changing their travel patterns in response to the 9/11 attacks, since these studies cannot track each individual’s transportation decisions.

But both studies suggest that a collective effort to avoid a highly visible danger can increase exposure to ordinary hazards whose victims are less visible. When more people choose to drive rather than fly, the roads become busier and the number of traffic deaths can rise.

The question shapes the risk estimate

One reason discussions about risk become confusing is that there is no single way to measure it. The answer to the question “Is it safe?” depends on what you measure.

How much risk does a person face for each mile traveled? What is the risk of one trip? How much risk accumulates during one hour of travel? What is the chance of dying from this cause in a year or over a lifetime?

These are legitimate questions, but to make a valid comparison, you need to look at the same measure of risk for both types of transportation. Comparing the risk of one flight with the annual risk of driving, for example, mixes unlike quantities.

A traveler deciding whether to fly or drive between two cities can compare the two modes over the same trip or distance. This comparison provides a clearer perspective than comparing a highly visible plane crash with a familiar daily routine.

Time matters too. In our estimates, an hour in a passenger car or truck carried about 74 times the fatality risk of an hour aboard a commercial aircraft.

Feeling in control is not the same as safety

Driving gives people a steering wheel, a brake pedal and the belief that their skill can protect them. Flying asks passengers to place control in the hands of pilots, airlines, regulators, air traffic controllers and a complex technical system. Psychological research has linked a stronger sense of agency – the feeling that people control their actions and their outcomes – with greater risk-taking. That difference in perceived control helps explain why a rare aviation disaster can feel more threatening than routine road travel.

Airline passengers don’t have the same sense of control over their vehicle as drivers, so flying can feel more uncertain and dangerous. AP Photo/Susan Walsh

Media attention also matters. A major airplane crash is treated as news of national or international importance. Road deaths occur across many locations and at different times, so the public does not see the cumulative toll.

The emotional intensity of coverage does not mean journalists are wrong to cover crashes. It just means audiences need context alongside the images.

Crafting better risk communication

Telling anxious travelers that flying is “safe” is rarely enough. Research on risk perception shows that people do not judge danger through statistics alone. Fear and vivid images also shape how risky an event feels. But providing more context about the risks from other forms of transportation can still help.

Effective communication about risk does not minimize tragedy or dismiss the real fear people may feel. But it can help people understand that when millions of travelers shift from one type of transportation to another, the risk moves with them.

For travelers, the practical question is not whether an option has zero risk. No option does. The question is whether a choice reduces their total exposure to risk or merely replaces a frightening, highly visible risk with a greater one that feels routine.

To put the rarity of fatal airline events into perspective, an average of 2.48 million travelers passed through TSA screening each day in 2025. Modern commercial aviation in the United States has achieved a safety record that is difficult to grasp precisely because fatal events are so unusual.

When fear leads people away from that system, the safest-feeling decision may not be the safest decision at all.

This article originally appeared on The Conversation. You can read it here.

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Photo credit: NASA – Gene Roddenberry, second from right, and Star Trek cast members visit the Space Shuttle Enterprise in 1976 with NASA Administrator James C. Fletcher, left. NASA

Exploration, Science

‘Star Trek’ and NASA have intertwined legacies – the show championed diversity and inspired generations of real space scientists

How science fiction helped shape real space exploration

Good Partner

9/8/2026

Deana L. Weibel

“Star Trek” began as a television series but grew into a cultural phenomenon.

When it premiered in 1966, no one could have predicted that it would lead to more than a dozen spinoff shows, more than a dozen movies and one of the most enduring fandoms in popular culture.

“Star Trek” is also unusual for its close connections to NASA, both in its storylines and in the real world. Decades of “Star Trek” adventures have ignited a love of spaceflight across generations, inspiring many who now work as space professionals.

I’m a cultural anthropologist who studies why people work in space exploration. I’ve interviewed astronomers, engineers, flight surgeons and astronauts. Although I focus more on science fact than science fiction, I’ve noticed in my interviews how much the two threads intertwine.

Because of this, I found myself at a “Star Trek” convention in early August 2026, just ahead of the show’s 60th anniversary on Sept. 8. The convention participants included people of widely different ages, appearances and identities. I was struck by just how much those gathered reflected the series’ values.

When NASA met Star Trek

In the original series, the show’s creator, Gene Roddenberry, came up with a philosophy held by the Vulcan people. He called it IDIC: infinite diversity in infinite combinations. It suggests that an ideal society is made up of many different types, all working together.

It represented Roddenberry’s rejection of conformity. It also explained why the Enterprise crew included a Russian alongside Americans, and Black, Japanese and female characters all in positions of responsibility and authority. While many ordinary viewers absorbed “Star Trek’s” lessons of camaraderie and acceptance, those involved in real space exploration also took notice.

The cast of ‘Star Trek: The Original Series’ included a diverse crew of characters. Walters Art Museum

Roddenberry established relationships with NASA personnel in the early days of his series. NASA provided photographs of planetary bodies and advice about the realities of spaceflight, as well as stock footage and access to certain NASA facilities.

Leonard Nimoy, who played the popular character Mr. Spock, was even brought to the National Space Club’s Goddard Memorial Dinner in 1967 as a special guest. Then-Vice President Hubert Humphrey gave the keynote speech. Afterward, though, it was Nimoy, not Humphrey, who found himself surrounded by the club’s members, including NASA employees, aerospace engineers, members of the military and government officials, all eager to meet the actor portraying the starship Enterprise’s first officer.

The relationship between NASA and “Star Trek” benefited the show by legitimizing the series. It also helped NASA by publicizing its work and depicting a positive future where its efforts to land on the Moon would eventually lead to visits to distant worlds – and amazing scientific advances like the show’s transporter and warp drive.

The connection between the space show and space agency was reflected in NASA’s decision to name its first space shuttle Enterprise, after some encouragement from the “Star Trek” fan community.

Inspiring astronauts

In 1977, actress Nichelle Nichols, who portrayed communications officer Uhura, was hired to recruit for NASA. The space agency had expanded its pool of astronauts to include scientists and other “mission specialists.” For the first time, an astronaut no longer needed to be a pilot to participate in a space mission.

NASA selected its first Black astronaut candidates and its first female astronaut candidates in 1978. While this move toward inclusivity may not have been directly influenced by infinite diversity in infinite combinations, it was compatible with it. “Star Trek” inspired many of NASA’s future employees. In interviews for my book “The Ultraview Effect,” a quarter of the space professionals I spoke with mentioned “Star Trek” as an influence.

Nichelle Nichols sits in the space shuttle simulator at the Johnson Space Center in March 1977. NASA

An Apollo astronaut I interviewed, for instance, said he believed humans would eventually “be able to go anywhere in the universe, just like ‘Star Trek.’”

A young engineer who had grown up in the 1990s told me his motivation came from the “opening line of ‘Star Trek’… to explore strange new worlds.”

A space shuttle mission specialist emphasized Roddenberry’s decision to make the starship crew multicultural, explaining: “Today I look at the diversity of it … he was setting the stage back when it wasn’t acceptable [in order] to be acceptable!”

A changing future

That influence has accompanied a changing astronaut corps.

Both the 2025 astronaut class, which for the first time included more women than men, and the crew of Artemis II, which sent the first woman, first Black astronaut and first Canadian on a lunar mission, resemble the future that “Star Trek” imagined.

The “Star Trek” fans at the convention I attended were even more diverse. It was clear to me that Roddenberry’s “infinite diversity in infinite combinations” isn’t just a concept from the series, but something that has become a defining value of contemporary Trek fandom.

NASA’s Spitzer Space Telescope captured a region of the galaxy that looks a little like the USS Enterprise, which NASA highlighted in a news release in 2016. NASA/JPL-Caltech

One such fan, Bjo Trimble, holds special status. She is credited with “saving ‘Star Trek’” when the series was almost canceled in 1968 after two seasons. Wearing a rainbow “IDIC” pin, she signed autographs at the SyFy Sistas booth, where T-shirts featuring Black “Star Trek” icons such as Uhura and Benjamin Sisko were on display.

However, with the Trump administration’s recent orders to dismantle all of NASA’s diversity, equity, inclusion and accessibility programs and policies, institutional support for “Star Trek’s” vision of acceptance and inclusivity, which flourishes in its fan base, is being undone. This rollback occurred just as NASA’s crews were reaching new milestones in representing the diverse future that “Star Trek” has encouraged for decades.

Sixty years later, some of the diverse future that “Star Trek” imagined has become part of everyday spaceflight. Other parts of that ideal remain unfinished.

This article originally appeared on The Conversation. You can read it here.

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Photo credit: Canva – What you flush away could help your garden grow.

Environment, Science

How D.C.’s ‘humanure’ fertilizer creates lush gardens and big profits while improving the environment

Human waste is helping grow lush greenery.

Erik Barnes

7/21/2026

The District of Columbia Water and Sewer Authority—now known as D.C. Water—has long provided water and sewer services to Washington, D.C. But for the past decade, the utility has also had an unexpected side hustle: turning human wastewater into fertilizer with flourishing results.

At most wastewater treatment plants, flushed water is cleaned, while the remaining solid matter is hauled away for disposal. Over time, transporting and disposing of that waste can cost millions of dollars while increasing carbon emissions from the trucks carrying it. A decade ago, however, D.C. Water decided to invest in transforming the solid waste into “humanure” rather than throwing it away.

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Growin’ grass and makin’ gas

At the end of the wastewater treatment process, the collected human waste solids are processed into biosolid fertilizer using technology developed by Norwegian company Cambi. The process doesn’t just produce high-quality fertilizer—it also generates biogas that can be put to good use.

“So you get up to 40% more biogas,” Cambi CEO Eirik Fadnes said. “That biogas can be used to generate electricity to be used elsewhere in the wastewater-treatment plant or put on the grid and sold.”

D.C. Water sells the biosolid fertilizer under the brand name Bloom, and it’s already proving to be a success. Bloom has been used throughout the Washington, D.C., area by customers including Catholic University, Mount Olivet Cemetery, and the Franciscan Monastery. It’s also used on numerous lawns, school grounds, community gardens, and golf courses.

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Success by the numbers

The numbers underscore D.C. Water’s success. To date, nearly 400,000 tons of Bloom have been sold across Washington, D.C., Maryland, Pennsylvania, and Virginia, generating $13.6 million in revenue. D.C. Water originally estimated it would take 20 years for Bloom to pay off its investment. But thanks to strong demand from institutions, landscapers, and local garden centers, the utility is now on pace to recoup that investment in just 12 years.

Bloom is also helping D.C. Water meet its environmental goals. By turning waste into a useful product instead of hauling it away for disposal, the utility has reduced its carbon footprint by roughly 50,000 metric tons of CO₂ emissions each year—the equivalent of taking more than 11,700 gas-powered cars off the road annually. The process also produces biogas, which can be converted into electricity to help offset the energy costs of wastewater treatment.

Human waste works wonders

None of this would matter if human biosolids weren’t effective at improving soil. “Humanure,” a term coined by Joseph Jenkins, refers to compost made from properly treated human waste. Because human feces can contain disease-causing pathogens, it must be handled carefully. After all, we call it “waste” for a reason.

When human waste is composted correctly, naturally occurring microbes break down the organic material while generating enough heat to destroy harmful pathogens. Over time, the result is a nutrient-rich compost that can improve soil health. Some farmers even build specialized outdoor composting toilets to create humanure for use on their land.

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Should D.C. Water continue on this path of simultaneous profitability and environmental improvement, it’s likely other wastewater treatment plants will follow its lead.

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