It began with a painting, a biologist and an idea to disprove the widely-held axiom that trees are static. The biologist first affixed a paintbrush to a tree branch, set it to a canvas and watched it sketch. She then multiplied the length of that tree’s stroke by every branch in its crown. In the course of a year, the biologist learned, the tree would move 187,000 miles — or seven times across the globe. This seemingly immobile thing was actually in constant motion.

The drawing and its implications would ultimately spark a program that has infiltrated some of the most impenetrable prisons in the nation, attracted international attention, and earned a spot on TIME Magazine’s list of best inventions. Called the Nature Imagery Project, it transports the soothing elements of nature into supermax prisons to help ease the psychological stress of solitary confinement.

The project is rooted in an idea that even the most static entities  — like trees, like inmates in solitary confinement — have the capacity for change. “Prisoners seem to be these people who will never change,” said the biologist, Nalini Nadkarni, a professor at the University of Utah. “They will always be violent, always a burden on society. But if we can change our perspective, we can see that people can move even if they seem stuck.”

A general consensus has emerged among politicians, academics and prison officials that something is seriously wrong with the way we isolate tens of thousands of prisoners in solitary confinement. But solutions to this seemingly intractable problem have been in short supply. Solitary confinement remains one of the most widely-used tools to punish or protect inmates, even amid overwhelming evidence linking isolation to mental illness and suicide.

So in 2010, Nadkarni delivered a Ted Talk with this issue in mind. She had been working with the Washington State Department of Correction, helping inmates raise endangered frogs. “The men here are choosing to come to our science lectures instead of watching television or weightlifting,” she said during her talk. “That, I think is movement.” She also at the time wanted something bolder. Something that would bring her hypothesis into the state’s most static corner: its solitary confinement units.

But “they didn’t want to do it,” she said. “They thought it would be coddling the prisoners.”

Then in 2013, her phone rang. It was a prison official at Oregon’s Snake River Correctional Institution, where the most violent and troubled criminals in the state end up. The official said he’d seen her Ted Talk. He said suicide was a problem in the prison’s solitary cells. Other inmates had become so agitated they needed to be forcibly extracted. He wanted to know if she could help.

Nadkarni said she had just the thing.

An oasis in the dungeon

There’s a whole vein of academic inquiry that studies how nature can soothe people separated from its reach. Consider the patient stuck somewhere in a towering hospital, the elderly encased in a nursing home, the employee laboring away in the bowels of an office building — and the inhabitants of the prison.

It doesn’t take much to do the trick. Just an outside view. Maybe an indoor tree. One experiment found patients with a view of nature recovered from gall bladder surgery faster than they would otherwise. Another study showed that disturbed viewers of a horror movie settled down more quickly with a natural view. Then, there’s this surprise: the nature doesn’t even need to be genuine. Patients near artificial plants, one study found, still recover at quicker rates.

That last study bears the germ of the idea of what would become the “Blue Room” at Oregon’s Snake River. There was no way Nadkarni could bring anything natural into one of creation’s most sterile environments. Not with its security apparatus. But she could, perhaps, fake it. She could forge an oasis in the dungeon.

Nadkarni remembers the drive out to to Snake River. It’s as remote as remote can be. Wedged in the eastern corner of Oregon along the arid border of Idaho, the environment streamed past her window, all browns and tans. “It’s very grim, as all prisons are, but this one was super grim,” she said. “It was this habitat bereft of anything except for sage brush. This place got struck by the ugly stick long ago.”

Even uglier was the intensive management unit, home to the state’s most troubled inmates. Inmates are in their cells 23 hours per day. Their one hour outside is also in solitude. “It’s the most extreme setting in the state,” said Lance Schnacker, a research analyst with the state youth authority who has studied the program’s efficacy. The inmates never see one another. “Essentially isolated the whole time. … No windows, no TV.”

Prison administrators showed Nadkarni a vacant room. E Block. It was empty save for some pull-up bars. This where she would conduct her experiment. This would become the Blue Room.

‘It’s Like I Forget I’m in Prison’

When Renee Smith, the correctional department’s behavior health services manager, first heard about the idea, she thought it would never work. These are complex issues. These are dangerous men — murderers, rapists, liars, cheats. How could the whoosh of the ocean or the cackle of crunching leaves possibly calm the state’s most tempestuous prisoners?

“I thought, ‘This is too simple,'” she said. “‘All we’re doing is putting nature images on the wall? How could this work? But if you’ve ever toured a prison, it’s a dreary place. It’s cement. It’s white walls. And that’s especially so if you’re living in a cell for 23 hours a day.”

“There were naysayers,” agreed Betty Bernt, spokesperson for the Oregon Department of Corrections. “There always are.”

But the prison nonetheless committed $1,500 to the project to buy a projector, which was set up in the room before a chair. The lights dimmed. Next, Nadkarni and another researcher, filmmaker Tierney Thys, chose a series of nature videos culled from National Geographic and other sources. The idea was to use the projector to splash the images across a blank wall and inundate the room with the soothing sounds of anything from the ocean to a creek.

The results were staggering. The inmates filtered in for an hour. When they emerged, they felt calmed. “When I’m irritated, it’s something soothing to me,” one inmate said in a questionnaire that Nadkarni administered. “I have pent up tension. Sometimes, [this helps] my mood mellow out.” Others said it gave them an “escape,” and helped them sleep better.

But officials saw something else. It became a tool to defuse a potentially volatile situation. If an inmate was stressed over something, they would recommend some time in the Blue Room. Or the inmates would request it.

“We had an inmate who was getting moved to another unit, and he wasn’t wanting to go,” said Smith, who quickly became a Blue Room convert. “Our team was suited up to extract him,” a process that could turn violent and injure either the inmates or guards. “But he said, ‘Just let me go into the Blue Room, and I’ll calm down.’ And he came back and said, ‘Okay, I can go now.'”

It’s difficult to quantify the full  impact of the experiment on the prison. But Schnacker said it has been “significant.” During the first year of the program, the number of disciplinary referrals — which involve matters like throwing feces or a violent outburst — increased in every other block in the isolation unit. But inside the block with Blue Room, the number went down — significantly. Researchers caution it’s still early to definitively link the project with that decrease. But there is cause for hope.

“If this is a true effect, then this intervention could have very important and powerful implications,” Nadkarni said. “However, we are still only partially through our analyses. … Our preliminary quantitative analysis on one experimental cell block in one prison suggests that our intervention to provide nature imagery to inmates is associated with a lower rate of violent infractions.”

Smith said it’s hard to know how much money the prison has saved by calming inmates who might have injured themselves with the nature imagery, but thinks it’s in the “thousands.” “We’ve probably saved a lot,” she added.

So it’s little wonder that prisons across the country and the world are calling Nadkarni about her work. One prison in Shelton, Wash., has already copied the program. And judging by the testimonial of some of the inmates who have used the Blue Room, they’ll keep calling.

“I’m about to get out of prison in 26 days,” one inmate said. “And it helped me get through my 10 months in [solitary]. Every time I’m in the Blue Room, it’s like I forget I’m in prison. And all my stress is gone.”