Science
That Arctic blast can feel brutally cold, but how much colder than ‘normal’ is it really?
Richard B. (Ricky) Rood, University of Michigan
An Arctic blast hitting the central and eastern U.S. in early January 2025 has been creating fiercely cold conditions in many places. Parts of North Dakota dipped to more than 20 degrees below zero, and people as far south as Texas woke up to temperatures in the teens. A snow and ice storm across the middle of the country added to the winter chill.
Forecasters warned that temperatures could be “10 to more than 30 degrees below normal” across much of the eastern two-thirds of the country during the first full week of the year.
But what does “normal” actually mean?
While temperature forecasts are important to help people stay safe, the comparison to “normal” can be quite misleading. That’s because what qualifies as normal in forecasts has been changing rapidly over the years as the planet warms.
Defining normal
One of the most used standards for defining a science-based “normal” is a 30-year average of temperature and precipitation. Every 10 years, the National Center for Environmental Information updates these “normals,” most recently in 2021. The current span considered “normal” is 1991-2020. Five years ago, it was 1981-2010.
But temperatures have been rising over the past century, and the trend has accelerated since about 1980. This warming is fueled by the mining and burning of fossil fuels that increase carbon dioxide and methane in the atmosphere. These greenhouse gases trap heat close to the planet’s surface, leading to increasing temperature.
Because global temperatures are warming, what’s considered normal is warming, too.
So, when a 2025 cold snap is reported as the difference between the actual temperature and “normal,” it will appear to be colder and more extreme than if it were compared to an earlier 30-year average.
Thirty years is a significant portion of a human life. For people under age 40 or so, the use of the most recent averaging span might fit with what they have experienced.
But it doesn’t speak to how much the Earth has warmed.
How cold snaps today compare to the past
To see how today’s cold snaps – or today’s warming – compare to a time before global warming began to accelerate, NASA scientists use 1951-1980 as a baseline.
The reason becomes evident when you compare maps.
For example, January 1994 was brutally cold east of the Rocky Mountains. If we compare those 1994 temperatures to today’s “normal” – the 1991-2020 period – the U.S. looks a lot like maps of early January 2025’s temperatures: Large parts of the Midwest and eastern U.S. were more than 7 degrees Fahrenheit (4 degrees Celsius) below “normal,” and some areas were much colder.
But if we compare January 1994 to the 1951-1980 baseline instead, that cold spot in the eastern U.S. isn’t quite as large or extreme.
Where the temperatures in some parts of the country in January 1994 approached 14.2 F (7.9 C) colder than normal when compared to the 1991-2020 average, they only approached 12.4 F (6.9 C) colder than the 1951-1980 average.
As a measure of a changing climate, updating the average 30-year baseline every decade makes warming appear smaller than it is, and it makes cold snaps seem more extreme.
Conditions for heavy lake-effect snow
The U.S. will continue to see cold air outbreaks in winter, but as the Arctic and the rest of the planet warm, the most frigid temperatures of the past will become less common.
That warming trend helps set up a remarkable situation in the Great Lakes that we’re seeing in January 2025: heavy lake-effect snow across a large area.
As cold Arctic air encroached from the north in January, it encountered a Great Lakes basin where the water temperature was still above 40 F (4.4 C) in many places. Ice covered less than 2% of the lakes’ surface on Jan. 4.
That cold dry air over warmer open water causes evaporation, providing moisture for lake-effect snow. Parts of New York and Ohio along the lakes saw well over a foot of snow in the span of a few days.
The accumulation of heat in the Great Lakes, observed year after year, is leading to fundamental changes in winter weather and the winter economy in the states bordering the lakes.
It’s also a reminder of the persistent and growing presence of global warming, even in the midst of a cold air outbreak.
Richard B. (Ricky) Rood, Professor Emeritus of Climate and Space Sciences and Engineering, University of Michigan
This article is republished from The Conversation under a Creative Commons license. Read the original article.
health and wellness
Lactose intolerance is actually the human norm – but racism, the US government and business interests have made it into a condition
Lactose intolerance is the global human norm, but Western dietary standards, government policies and commercial interests helped frame it as a medical deficiency.
Hilary Smith, University of Denver
Lactose intolerance makes drinking milk or eating ice cream a literal pain. For some people, eating a dairy treat can lead to bloating, nausea and diarrhea. You might’ve experienced its effects yourself. If so, you may think of lactose intolerance as a defect rather than the norm.
But did you know that most people in the world today are lactose intolerant – and that the condition itself was invented in the 1960s?
“Surely you mean discovered, not invented,” I hear you saying. I don’t. As a historian who has traced the origins of nutrition-science ideas, I have chosen the word “invented” on purpose.
Inventing lactose intolerance
Variations in people’s ability to digest lactose first came to scientists’ attention after American dairy producers found a way to rid themselves of a postwar milk surplus. To offload what they couldn’t sell, they looked to the government to intervene. And it did, buying the excess and embedding it in school lunches and other places with publicly funded meals.
Suddenly, many people who had not habitually drunk milk were consuming it regularly, including not only some Americans but also people overseas. Part of that same milk surplus found its way into school lunches in places such as Japan and Taiwan in the 1950s as the American government began to sell milk to allies during the Cold War.
Many of the groups drinking milk regularly for the first time did not like it. In fact, it made them feel sick. Intrigued, scientists set up experiments to figure out why. In a 1966 study comparing how Black and white people incarcerated in Baltimore metabolized lactose, researchers found that Black participants had lower levels of lactase – the enzyme that breaks down lactose – in their guts.
To the white scientists conducting this study, the trouble that the Black prisoners had digesting milk looked like an “inborn error of metabolism.” They assumed that the normal human state was lactose tolerance and that the lactose intolerant had inherited a genetic mutation.
It was only after years more work with research participants of many races that experts realized that, as one National Institutes of Health official put it in 1981, “lactose intolerance is a normal physiological condition, shared by every adult animal except for certain ethnic and racial groups in man.” People of northern European descent, it turned out, were the weird ones. It was their ancestors who had passed down a genetic mutation – one that made them able to digest milk after infancy.
In short, what scientists discovered in the 1960s was that different bodies process milk differently. What they invented was the idea that lactose intolerance is a defect. Accepting that framing would mean nearly two-thirds of the human population – the estimated prevalence of lactose intolerance worldwide – is defective.
Instead of acknowledging that dairy-free diets can be healthy, people innovated ways to overcome this supposed disability so everyone could consume more.
Nutritional imperialism
Lactose intolerance is one example of what I call nutritional imperialism: a way of thinking that treats white diets as the norm and everyone else’s as an aberration.
Nutritional imperialism was common in the 20th century, when scientists thought that not only milk-rich but also meat-heavy diets were best; they considered diets outside of the United States and Europe too vegetarian. Some also argued that wheat flour, not rice, ought to be the universal staple.
The same bias applied to bodies. Besides faulty lactose digestion, nonwhite bodies were accused of other failures, too, such as aldehyde dehydrogenase deficiency, an inability to digest alcohol quickly. The less technical term for this may be more familiar: Asian flush.
Such differences might have been thought of as variety, just another way of being human. Instead, each became a deficiency.
Many people today have inherited and perpetuated this way of thinking without knowing it, including those who are deemed deficient by it. In 1959, the director of Japan’s nutrition bureau declared that “rice-eating peoples” such as the Japanese were “resigned and passive” and could correct this by imitating Western diets and switching to wheat.
Today, the most prominent scientist promoting the idea that Asian flush is a disease is a geneticist of Taiwanese descent who started a research consortium to study “the most common human enzymopathy in the world.”
The Chinese Nutrition Society placed a tall glass of milk next to its 2022 Food Guide Plate – never mind estimates that the vast majority of Han Chinese, the largest ethnic group in China and worldwide, are lactose intolerant.
Turning sickness back into difference
Science that pathologizes difference helps racism persist.
In recent years, white supremacists have embraced the concept of lactose intolerance as a distinguishing debility of nonwhite people. Social media users have copied and pasted a map of the geographic distribution of lactose tolerance originally published in the scientific journal Nature into racist chat threads on the online discussion forum 4chan.
In 2017, internet trolls disrupted an anti-racist art installation with neo-Nazi chants and messily downed jugs of milk to accentuate their white identity.
Turning a lactose-digestion difference into a deficiency has done more to reinforce narratives of racial hierarchy than to improve public health. So here’s a suggestion: If you enjoy eating dairy, keep doing it; if you don’t, don’t – and know that there is nothing wrong with you.
Hilary Smith, Professor of History, University of Denver
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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News
FAA Certifies Boeing 737-7: What It Means for Airlines and the 737 MAX Program
The FAA has certified Boeing’s new 737-7, clearing the smallest 737 MAX variant for service as Boeing and Southwest prepare for first deliveries.
The U.S. Federal Aviation Administration has certified Boeing’s new 737-7, granting the company an amended type certificate that clears the smallest member of the 737 MAX family for commercial service. The milestone closes a multi-year certification effort and puts the focus on execution: Boeing and launch customer Southwest Airlines say preparations are underway to support first deliveries.
For STM Daily News readers, the headline isn’t just “another plane gets approved.” It’s a signal that Boeing has now cleared a key MAX variant designed for long-range flexibility in a smaller footprint—an aircraft type airlines can use to open or defend routes where demand is strong, but not strong enough to justify a larger narrowbody.
What FAA certification means
An amended type certificate means the FAA has approved the 737-7’s design as compliant with commercial aviation regulations. In practical terms, certification allows airlines to place the aircraft into revenue service once deliveries begin and operator-specific steps—training, manuals, maintenance programs, and entry-into-service planning—are completed.
Boeing also said the FAA updated Boeing Production Certificate No. 700 (PC 700) to include the 737-7, supporting production and delivery activities.
Why the 737-7 matters in the MAX lineup
Boeing positions the 737-7 as the smallest and longest-range member of the 737 MAX family. The company says it typically seats 135 to 160 passengers in a two-class configuration and offers a range of up to 3,800 nautical miles (7,040 km). That combination matters because it gives airlines more options to fly longer “thin” routes—markets where frequency and reach matter more than packing in additional seats.
Boeing also highlights performance for operations out of high-altitude airports and in hot climates, where takeoff performance and payload-range tradeoffs can shape fleet decisions.
Efficiency claims: fuel, emissions, and noise
Boeing says the 737-7, like other 737 MAX jets, reduces fuel use and CO2 emissions by 20% and cuts the noise footprint by 50% compared to the airplanes it typically replaces. For airlines, those improvements typically show up in two ways:
- Route economics: lower fuel burn can improve margins on longer sectors and reduce exposure to fuel-price swings.
- Operational constraints: quieter aircraft can help with airport noise requirements and community pressure, while lower emissions support sustainability targets.
Inside the certification effort
Boeing said the certification program began in 2018 and included more than 1,000 hours of flight and ground testing, extensive system safety analysis, and human factors reviews. The company also noted an updated engine anti-ice system to address a potential condition discovered during flight testing.
Boeing Commercial Airplanes President and CEO Stephanie Pope called the certification “important” validation of the airplane’s design and the work of the MAX development team. Mike Sinnett, senior vice president of Product Strategy, Product Development and Development Programs, said Boeing held regular discussions with the FAA and that the process has sharpened the company’s understanding of current regulatory requirements—knowledge Boeing expects will accelerate future development with a renewed emphasis on human factors, safety, and quality.
What to watch next
With certification complete, the next phase is about delivery timing and real-world deployment.
- First deliveries to Southwest: Boeing and Southwest are preparing for delivery of the first airplane, including updates to final configuration.
- Production stability: certification removes a major hurdle, but supply chain health and production cadence will determine how quickly the 737-7 shows up in airline schedules.
- The 737-10 timeline: Boeing reiterated it is working to certify the 737-10 this year, keeping attention on how quickly the final MAX variant clears regulatory review.
The bigger MAX picture
Boeing said the 737 MAX family order book stands at more than 7,200 airplanes, with more than 2,300 delivered through the end of June 2026. The 737-7’s certification adds another deliverable product to that portfolio—one aimed at airlines that want long range without stepping up to a larger gauge.
Bottom line
FAA certification of the 737-7 is a meaningful milestone for Boeing and for airlines looking for a smaller narrowbody with long-range capability. The real test now is operational: turning certification into on-time deliveries and reliable entry into service—while the industry watches Boeing’s push to certify the 737-10.
Related Links
- Boeing 737 MAX family overview (manufacturer background/specs): https://www.boeing.com/commercial/737max/
- FAA Aircraft Certification (how type certification works): https://www.faa.gov/aircraft/air_cert/
- FAA Airworthiness Directives (regulatory actions database): https://www.faa.gov/regulations_policies/airworthiness_directives
- Southwest Airlines newsroom (launch customer context / fleet updates): https://www.swamedia.com/
- Boeing Commercial Airplanes newsroom (for follow-ups and official updates): https://boeing.mediaroom.com/news-releases?item=130821
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Source:
Boeing (PRNewswire), Aug. 3, 2026 — “U.S. FAA certifies new Boeing 737-7 airplane.”
Nature
What in the Heck Is a Sweat Bee? Turns Out, My Wife Wasn’t Making It Up
My wife Rebecca said she thought a sweat bee stung her. I thought she was making it up. Turns out, sweat bees are very real—and their strange name actually makes perfect sense.
It started with a conversation with my wife, Rebecca.
She mentioned that she thought she’d been stung by something called a “sweat bee.”
My immediate reaction was basically:
“What in the heck is a sweat bee?”
I’ll admit it. For a moment, I thought she was making the whole thing up. 😂
A sweat bee? Really?
It sounded like one of those names somebody invents when they don’t know what actually stung them.
“It wasn’t a regular bee. It was a… uh… sweat bee!”
So naturally, I asked ChatGPT the same question: What in the heck is a sweat bee?
Well, Rebecca gets this round.
Sweat bees are absolutely real.
And Yes, They’re Interested in Your Sweat
Sweat bees belong primarily to the Halictidae family, a large group of generally small bees found around the world.
Some are rather ordinary-looking little insects, while others are surprisingly flashy, sporting metallic shades of green, blue, bronze or gold.
But here’s where they earned that wonderfully unfortunate name.
Some sweat bees are attracted to human perspiration.
They’re not after you because they’re angry, and they’re certainly not tiny vampire bees. They’re interested in the salt and minerals in your sweat.
In other words, after you’ve been outside working, gardening, exercising or simply trying to survive a hot summer afternoon, a sweat bee may look at you and think:
“Hey! Free electrolytes!”
Wait…They Can Sting Too?
Unfortunately for Rebecca, there’s another part of her story that checks out.
Female sweat bees can sting.
They’re generally not aggressive and aren’t flying around looking for people to attack. But if one gets trapped against your skin, squeezed or swatted, it may defend itself.
Their sting is generally considered relatively mild compared with those of many other bees and wasps—but “relatively mild” probably isn’t much consolation when you’re the person who just got stung.
So, Rebecca, I officially withdraw my skepticism.
Mostly.
Don’t Declare War on Them
As annoying as having a tiny bee land on your sweaty arm might be, sweat bees are actually beneficial insects.
They’re important pollinators, visiting wildflowers, garden plants and agricultural crops and carrying pollen from flower to flower.
So if one lands on you, gently brushing or blowing it away is probably a better idea than swatting it against your skin.
And that’s today’s unexpected nature lesson.
Sweat bees are real.
They really are attracted to sweat.
The females really can sting.
And, perhaps most importantly…
My wife was right.
There. I said it.
I’m sure I’ll never hear the end of this one. 😂
Related Links
- University of Arizona Cooperative Extension — Arizona Bee Identification Guide — A useful Arizona-focused guide that includes sweat bees and explains their appearance, size, nesting behavior and attraction to salt in perspiration.
- USDA Natural Resources Conservation Service — Native Bees and Their Favorite Flowers — More information about native pollinators and the important role sweat bees play around wildflowers.
- USDA Forest Service — Bee Basics — A broader guide to North American bees, including the colorful metallic members of the sweat bee family.
- Smithsonian National Museum of Natural History — Sweat Bee — See an actual female sweat bee specimen (Augochlorella aurata) and its scientific classification.
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