The Brief

This story was originally published on August 24, 2023 and has been updated to include a rerun of the podcast episode.

There is a moment of awe that washes over you when you step into a forest. Century-old trees tower above, sunlight twinkling through them. Birds tweet. Spiders weave their elaborate webs. The smell of pine needles fill the air.

The act of spending time in the forest is what the Japanese call shinrin-yoku, a term originating in the 1980s that means "bathing in the forest atmosphere," says Qing Li, a researcher on this topic and a professor at Nippon Medical School in Tokyo. "This is not exercise or hiking or jogging," he writes in his 2018 book Forest Bathing: How Trees Can Help You Find Health and Happiness. "It is simply being in nature, connecting with it through our sense of sight, hearing, taste, smell and touch."

Not only is "forest bathing" a magical way to explore nature, decades of research has shown that it's good for your health. It can boost your immune system, lower blood pressure and help with depression. It can also reduce the stress hormones cortisol and adrenaline and turn down the dial on your body's fight-or-flight response.

Li and Gary Evans, director of the Forest Bathing Institute in the U.K., talk to Life Kit about the science behind forest bathing and how you can reap these health benefits.

1. Find a location where you're surrounded by trees

The ideal place to forest bathe is well, in a forest. But if you live far away from one or don't have the means to get there, any place that has a lot of trees and quiet spaces will do.

"You can also get beneficial effects from a city park," says Li, but they won't be as significant as walking in the deep woods. A 2022 study published in the International Journal of Environmental Research and Public Health found that walking in a forest park had a greater impact on cardiovascular function than doing so in an urban park.

Walking in an urban park still has health benefits. Another study published in 2022 found that it can significantly improve mood and reduce stress, compared to walking in an urban gray setting.

2. Set aside a good chunk of time

To reap the ultimate rewards of shinrin-yoku, plan to spend two to six hours in the woods, says Li.

His research showed that forest bathing for about that amount of time helped boost immunity. One study found that participants who walked in the forest for two hours in the morning and two hours in the afternoon saw an increase in anti-cancer proteins and immune cells that kill tumors, with the effects lasting for at least seven days after.

If you can't set aside a good part of your day to meander through the forest, you can also do shorter walks. But the health benefits won't be as significant, says Li. "The longer [the time in the forest], the better. The longer has more effect."

A 2019 study published in the International Journal of Environmental Research and Public Health found that walking just 15 minutes through the woods can help relieve stress and anxiety.

3. Aim to reduce heart rate

Your forest bathing session is a good time to sit or walk or do some gentle yoga or tai chi. It's not the time to squeeze in your hardcore cardio for the week.

"The difference between normal activities and forest bathing is that we're going to move very slowly," says Evans. Forest bathing is about calming down your nervous system and reducing your heart rate and blood pressure.

If you exert yourself too much physically, your "tiredness will reduce the effect of forest bathing," says Li. Your body will produce more stress hormones such as adrenaline, noradrenaline and cortisol, which studies have shown that forest bathing can help decrease.

4. Breath in the scents of the forest

Many of the benefits of shinrin-yoku come when we inhale the chemicals that trees release into the air, called phytoncides, says Li. They can reduce our stress hormones and increase our levels of white-blood cells known as natural killer cells, according to his research.

In one study from 2009, his team ordered special concentrated essential oils made from Japanese cypress trees and then pumped them into the hotel rooms of test subjects using a diffuser. The people staying in those rooms saw about 40 to 50% of the health benefits as those who did a forest bathing session.

As a side note, if you can't make it to a forest, Dr. Li says you could get some of the benefits by diffusing tree-based essential oils at home.

5. Bolster your forest bath with meditation

When you get to the forest or the park, walk a little bit and then find a spot that speaks to you. That could be a clearing in the woods surrounded by a bunch of tall trees or a spot where a tree has grown into a curved shape that looks suspiciously like a seat. If it feels beautiful and resonant to you, that's what matters.

Now sit down, says Evans, and try this exercise. "Inhale for a count of one, two and then exhale for double the length of time, so it's one, two, three, four. Then keep that going."

"When the exhale is slower than the inhale, it sends a physiological message to your body that says: 'I'm safe. I can relax. It's OK,' " he adds.

This particular breathing exercise has been shown to have benefits on its own outside of the forest environment. The reason to do it in the forest is to allow yourself to relax so you can begin to notice all the sounds, colors and textures that nature has to offer.

You may be surprised by what you discover, says Evans. "Depending on what's happening in your emotional world, quite often when we look at nature or the forest, it sends something back to us to help us make sense of what's going on in our life."

This episode of Life Kit was produced by Clare Marie Schneider. The digital story was edited by Malaka Gharib. The visual producer is Kaz Fantone.

Copyright NPR 2024

Fifteen years ago, when modern electric vehicles were just hitting the road, no one knew exactly what to expect from their giant, expensive lithium-ion batteries.

As batteries age, they hold less and less energy. Anyone who's ever had a dying smartphone, or had to replace a vehicle's 12-volt starter battery, knows this painfully well.

EV batteries were intended to last longer than those smaller, cheaper batteries. But how much longer?

The predictions were not soothing. In 2010, the New York Times wrote that "estimates of [EV] battery packs' lifespan — no one knows for sure — range upward from seven years." The average car on the road is more than 12 years old. And that discrepancy made some would-be EV buyers nervous.

Batteries come with warranties, but they don't last as long as the car. If a high-voltage battery chokes out midway through a car's life, it needs replacing — at a price tag that can run in the ballpark of $5,000 to $20,000.

But there's good news.

As the fleet of EVs on the road ages, new data pooled from tens of thousands of vehicles is showing those batteries are lasting longer than expected.

How a battery ages 

Lithium-ion batteries undergo two kinds of aging. First, there's calendar aging: They degrade as time goes on, holding less juice, even if they just sit in storage.

Then there's cyclical aging, which is how much a battery degrades based on its use — being charged and discharged, over and over again.

That means there's no way to dodge degradation. Whether you use a vehicle a lot or a little, eventually, the battery will hold less energy.

But the trajectory of aging isn't a straight line. Recurrent, a research firm that pulls in data from over 30,000 EV drivers, describes it as an "S curve." There's a rapid decline at the beginning, a long leveling off, and then a more rapid decline at the end.

"It's very much like breaking in a pair of shoes," says Liz Najman, the director of market insights at Recurrent. The shoes start out stiff, but quickly get a little more give. "And then your shoes just last you," she says, until at some point, "It's all over, it's a rapid decline."

And when it comes to EV batteries, two things are becoming clear. The initial drop-off is not as severe as some people had worried. And the sharp end-of-life decline is taking a long, long time to materialize.

At auto auctions, a lot of healthy batteries

Adam George is a vehicle services director at Cox Automotive, which runs used car auctions around the country. In recent years, the number of used EVs for sale has increased enormously — reflecting the sharp rise in production a few years ago.

That's given Cox Automotive a growing pool of used EVs to evaluate before they're re-sold.

"We were expecting battery health to be experiencing mass degradation over the first one to three years of owning a vehicle," George says. "What we have seen, though, is that these 2, 3, 4-year-old off-lease cars that are coming back have battery health scores well upwards of 95%."

Recurrent's data also shows that cars from most major brands retain 95% or more of their expected range after 3 years, thanks in part to software and battery management systems that are designed to correct for the battery's early degradation, and give drivers consistent range.

So the initial drop-off in that S curve is in the range of 5% or so, give or take. After that? Well, Cox Automotive has tested nearly 80,000 EVs, and found an average battery health of 92%.

Decade-old EVs are overwhelmingly on their original batteries 

That data set is naturally skewed toward younger vehicles, because the vast majority of EVs on the road today are fairly new. There were only a million EVs sold between 2010 and 2018, and now there are more than a million sold each year.

So what about the oldest EVs, specifically?

Recurrent's data can help answer this question. Najman, a data scientist, notes a few caveats: It's a fairly small dataset, just because there weren't many EVs built more than a decade ago. And some of the oldest EVs use technology that can't connect to Recurrent's opt-in network.

But based on their community, among EVs that are 10 years old or older, only 8.5% have ever had a battery replacement. More than 90% of them are still on their original battery.

"EV batteries are holding up phenomenally well," Najman says.  

Recurrent has also looked at EVs of any age that have more than 150,000 miles on them, which provides a closer look at the effects of that cyclical aging. There, too, the batteries outperformed expectations.

"Cars with 150,000 miles or more, and that have not had battery replacements, are getting at least 83% of their original range," Najman says.

Now, there is one common reason why EV batteries will be replaced very early on: a defect. There have been multiple large-scale battery recalls, and any individual battery might have a flaw that requires replacement. But because all new EVs come with warranties, that kind of replacement isn't a financial blow to owners.

"That would be something that would be synonymous with, like, your engine or a transmission going bad," says Adam George, of Cox Automotive. "That's what warranties are for."

EV battery warranties typically cover at least 8 years and 100,000 miles, and automakers will replace the battery in the case of catastrophic failure, or a reduction in capacity (usually to 70% of the original or less).

A robotic arm displays the dual engine chassis of a Model S electric sedan at the Hawthorne Airport in Los Angeles on October 9, 2014.

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The tale of one Model S 

What do all these stats look like in real life? Consider Norman Hajjar's Model S.

Hajjar was an early adopter of electric vehicles. He kind of had to be: In 2013 he became an executive at the electric vehicle drivers' app Plugshare.

His 2012 Model S is one of the first that Tesla ever built. When he got it, he was well aware of the question mark about battery lifespan. "There was really no way of knowing what the future held for it because there was zero track record," Hajjar says.

In his case, the future held a battery defect: a loud noise followed by his car coming to an abrupt stop. He recalls Tesla replacing the battery — free of charge and under warranty — in 2014.

Since then, he's spent 12 years on that second battery. He's put around 200,000 miles on the car overall. And it's driving great, thank you very much.

"This vehicle still is a monster," Hajjar says, affectionately. "It is extremely fast, quick off the line."

The vehicle was originally rated to have 265 miles of range. Now it has about 220. Do the math, and it's at 83% of its original capacity. "The amount of degradation is pretty minor," Hajjar says.

Hajjar has moved on to a newer vehicle for his daily driver, mostly to enjoy higher-tech features. (His newer Model Y has Tesla's advanced driver-assistance software.) His son uses the Model S these days for his commute to college. "It's just sort of a backup vehicle now," Hajjar says. But he plans to hang on to it. He's sentimental about it, he says.

Why are batteries outlasting expectations? 

The engineers who developed modern EVs knew that prolonging battery life would be crucial. They designed systems to actively manage temperatures to improve battery lifespan, and software to constantly check battery health. Years have shown those efforts paid off.

But there's another reason EV batteries have out-performed expectations. It turns out that testing batteries is harder on them than the real world. Their lifespan was underestimated.

Simona Onori's lab at Stanford University has done research into the longevity of lithium-ion batteries, including a 2024 paper in Nature Energy showing that traditional methods for testing battery life are very stressful, and don't match the way batteries are actually used.

In most lab tests, researchers repeatedly cycle them from a very high state of charge to a very low one.

Real-world driving is gentler, with stops and starts — each start draws a bit of the battery's energy down, while each stop gives it a little time to recharge. A driver would never slam the accelerator to the floor and keep it there until the battery is dead.

"We accelerate, we decelerate," Onori says. "The battery will be charged, and discharged, some rest if you're at a traffic light."

Her lab's findings suggest that the traditional tests for battery life were unrealistically challenging, and Onori says ongoing work with real-world data is now confirming that. When they're actually driven, she says, EV batteries "age gracefully. Very gracefully."

Just like humans, she notes: "When we live a life with less stress, we live longer."

A decade plus … and counting 

So how long do EV batteries last? It's still too soon to put a precise number on it, because — as a group — the cars already on the road haven't yet reached the end of the S-curve, the point when they will start to show massive performance declines. In other words, they're not dead yet.

Meanwhile, battery technology keeps improving. The oldest EVs, like Hajjar's Model S, may not be the best indicator of how long newer EVs will last. Software systems to manage batteries have gotten more sophisticated. A lot of new EVs use a different battery chemistry — lithium iron phosphate or LFP — which lasts even longer than other lithium-ion batteries.

As Stephanie Valdez-Streaty, who follows EV trends for Cox Automotive, puts it: "These batteries are built to outlast the cars."

And there's one more wrinkle when it comes to figuring out the end of life for a normally-aging EV battery. They don't die abruptly, like an old engine cutting out. It's more that their range shrinks; they can only hold enough energy for shorter and shorter trips. Instead of shelling out for an expensive battery replacement, some EV owners might just put up with that limitation.

Thomas McVeigh, of Ontario, Canada, drives a 2014 BMW i3. That vehicle didn't have an impressive range even when it was new, and now it can only manage about 55 miles on a single charge in the winter. But it still looks great. It's pleasant to drive. It saves him on gas. Maintenance is wildly cheap for a 12-year-old vehicle, and especially for a BMW; his only real cost is new tires.

He's fine with its diminished range. And he's not inclined to put what he estimates would be a $6,000 battery into an aging car. Instead, maybe he'll pass it on to his kid. "Teenagers generally aren't going for long drives," he says.

Or maybe he'll keep it for himself, after all. "I mean," he says, "I love that car."

Copyright 2026 NPR

This week the Getty Villa Museum will begin offering a rare look at scrolls from its ancient Egyptian “Book of the Dead” collection.

The collection of 19 manuscripts written on scrolls of papyrus and linen fragments are fragile, with one of them dating back nearly 3,500 years. Because of that, the materials are not usually on display to the public and the gallery will be carefully lit, temperature and humidity-controlled.

Sara Cole, associate curator of antiquities, told LAist that a lot of the language in the spells is written in first person speech for the deceased spirit to say while navigating the afterlife.

“One of my favorite phrases that I have on a wall of the gallery is ‘May I join with the stars that call out to me in the night boat,’” Cole said.

Cole explained that the manuscripts have been in the Getty’s collection since 1983, when they were donated by a bookseller in New York, who got them from the private collection of a British rare manuscript collector.

Egyptian mummy wrapping of Petosiris, Son of Tetosiris, from around 332–100 BCE.

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A years-long project is underway to translate the spells and rituals immortalized in the Getty's “Book of the Dead” scrolls and fragments, with a “large publication” in the works, Cole said.

The exhibition will feature four papyri belonging to women named Webennesre, Ankhesenaset, and Aset. Cole said “Book of the Dead” materials belonging to women are rare, because most were reserved for men.

Twelve of the manuscripts in the exhibition are written on fragments of linen that were used to wrap the mummified remains of the people they belonged to. Cole said she hopes visitors will understand that the material was very intimately associated with peoples’ burials.

Cole said her goal is to foreground the identities of the people who owned the scrolls, including two women who were ritual singers for the god Amun in the ancient city of Thebes.

“We see in these manuscripts the ancient Egyptians really grappling with this question and thinking about what might happen when we die... And I think that’s something we can all connect with and understand,” she said.

Cole recommends visiting the Getty’s website for a calendar of curator tours and special events related to the exhibition, including an upcoming talk by an Egyptologist.

The “The Egyptian Book of the Dead” at the Getty Villa runs from March 4 to Nov. 30.

The Supreme Court hears arguments Monday in an important gun case that has united an array of strange bedfellows, from conservative gun rights groups to liberal civil liberties groups. At issue is a federal law making it a crime for drug users to possess a firearm. It's the same law that was used to prosecute then-President Joe Biden's son for illegal gun possession — only this case involves marijuana use and gun ownership.

The briefs in the case present diametrically different versions of the facts. On one side, the Trump administration portrays Ali Danial Hemani as a drug dealer and someone with terrorist ties and a marijuana habit. Importantly, he is not being prosecuted for any of those offenses, however. Rather, the government has charged Hemani with violating a federal gun law that bars people with drug addiction from possession of firearms, a crime punishable by up to 15 years in prison.

The 5th U.S. Circuit Court of Appeals threw out the indictment, declaring that the federal law violates Hemani's Second Amendment right to own a gun.

The Justice Department appealed to the Supreme Court, arguing that because Hemani admitted to FBI agents that he used marijuana several times a week, he is a "persistent" drug user, thus rendering illegal the possession of the gun he bought legally and keeps securely in his home.

Hemani's lawyer, law professor Naz Ahmad of the City University of New York, paints a very different picture of her client. Hemani, she notes, was born and raised in Texas, "attended high school there, played on the high school football team, attended the University of Texas at Arlington, was an honor student there" and is "a really valued member of his local religious community."

"The Second Amendment doesn't support disarming and prosecuting somebody for mere possession of a firearm if they happen to have used marijuana occasionally," she says.

"That's a mismatch," she adds, especially at a time when 40 states, to one degree or another, have legalized marijuana use.
 
If the court rules against Hemani, she says, "the statute could apply to anybody. It could apply to somebody who uses like a marijuana sleep gummy."

The Trump administration's advocate, Solicitor General D. John Sauer, acknowledges that under the Supreme Court's landmark gun decision four years ago, the government has a heavy burden to show that modern-day gun laws are analogous to laws in place at the nation's founding. But he contends that the statute used to prosecute Hemani is both justified and analogous to founding-era laws and practices.

Specifically, in his Supreme Court brief, Sauer points to the harsh punishments imposed during the founding era on "habitual drunkards." And he contends that both Congress and the states have restricted firearm possession by illegal drug users "for as long as that social evil has plagued America."

That said, for the most part, the case seems to have united groups from left to right, from civil liberties groups to gun rights advocates.

"It's outrageous that they tried to get him on a marijuana gun charge," says Aidan Johnston, director of federal affairs for Gun Owners of America. He contends that the government is seeking to criminalize conduct that was widely tolerated at the founding.

"It was the universal custom of founding-era militias to imbibe," he notes, adding that Thomas Jefferson and other famous Americans "possessed firearms while being users of drugs ranging from opium to cocaine."

At the opposite end of the ideological spectrum are a variety of gun-safety groups that fear that if Hemani wins his case, it could gouge a hole in the existing system of national background checks.

Under the current system, dealers are required to first clear the sale by submitting the buyer's name to the FBI's National Instant Criminal Background Check System. The hitch is that there is a very small window in which to complete the check — just three days. And gun-safety groups say that anything that makes the rules more complicated and unclear could really screw up the system.

"We're saying" to the court, "whatever you do, it's essential that you keep the rules clear so that in that short window, federal agencies can give a quick answer to the dealers," says Douglas Letter of the Brady Center to Prevent Gun Violence. 

An adverse ruling, he says, would mess up the criminal background check process. That, in turn, would result in "so many, particularly women and children, who will die if that kind of a system is not in place."

A decision in the case is expected by summer.
Copyright 2026 NPR

Longtime administrator Andres Chait addressed the public as acting superintendent of Los Angeles Unified School District for the first time Monday.

“ We remain committed to academic excellence and student wellbeing,” he said ahead of a closed board meeting to discuss his employment and ongoing labor negotiations with district unions. “Our core values remain unchanged. I know transitions can create uncertainty, but our district is strong.”

After meeting for about four hours, the Board recessed the closed-door convening until March 10 at 9 a.m., the same day as the next regularly scheduled meeting.

Chait has worked for the district for nearly three decades, most recently as chief of school operations. His responsibilities included overseeing school safety, athletics and the district’s office of emergency management.

The LAUSD board voted unanimously Friday to place Superintendent Alberto Carvalho on paid administrative leave “pending investigation,” and appointed Chait in his stead. FBI agents searched Carvalho’s home in San Pedro and district office Wednesday.

A justice department spokesperson said the agency had a court-authorized warrant but declined to provide additional details. The reason for the searches is unknown.

Listen to Chait's full comments