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What could provide the ultimate solution to energy challenges for an advanced civilization? Freeman Dyson, a celebrated British-American physicist, postulated such a solution: a massive shell made up of mirrors or solar panels surrounding a star, capturing all of its energy output.

“Within a few thousand years of industrialization, one should find any intelligent species inhabiting an artificial biosphere completely encompassing its parent star,” Dyson argued in a 1960 paper introducing this concept.

Though it sounds like science fiction, that’s because it is: Dyson took inspiration from Olaf Stapledon’s 1937 novel “Star Maker,” something he openly acknowledged. Dyson, now a late professor emeritus at Princeton’s Institute for Advanced Study, was well-known for such creative thinking.

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Despite its sci-fi roots, the idea gained traction, especially given that some colleagues believe Dyson’s early work could have earned him a Nobel Prize. These hypothetical massive structures became labeled “Dyson spheres,” though Dyson clarified that they would more likely consist of “a dispersed collection or swarm of objects, each in individual orbits around the star.”

Dyson also suggested that such structures would radiate waste heat detectable as infrared emissions and proposed searching for extraterrestrial life by finding such emissions. However, he noted that infrared radiation doesn’t automatically indicate advanced life; it might also point to new types of astronomical objects.

“Scientists (of the time) weren’t counting on discovering alien civilizations; they were more interested in the idea that waste heat was a good lead to follow,” said George Dyson, a technology historian and Dyson’s son, in an email. “While science fiction embraced the Dyson sphere idea, social critics saw it as a metaphor for questioning uncontrolled technological expansion.”

The elder Dyson himself maintained that searching for intelligence directly would be more rewarding, though technology was "the only thing we might actually detect.”

In the 1960s, there was no real way of seeking Dyson spheres. Yet, modern researchers have taken up the charge, including teams at the SETI Institute and Fermilab. A recent study, surveying 5 million stars in our galaxy, uncovered seven possible Dyson sphere candidates—findings now undergoing rigorous scrutiny.

Exploring Potential Candidates

The study, published in the journal Monthly Notices of the Royal Astronomical Society on May 6, searched specifically for Dyson spheres by seeking unexplainable infrared heat from stars.

The team analyzed data from telescopes designed to detect infrared light and focused on stars located less than 1,000 light years from our solar system. “We began with a dataset of 5 million stars and applied filters to minimize data contamination,” said lead researcher Matías Suazo, a doctoral student at Uppsala University, Sweden.

“So far, we have seven sources emitting infrared light, but we don’t yet know why, so they’re intriguing,” Suazo continued.

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Suazo cautioned that definitive proof that these stars house Dyson spheres remains elusive.

“We’re struggling to find concrete explanations for these sources. They could align with our Dyson sphere models, but there’s also a chance they are something unexpected,” he said, adding that possibilities such as coincidental alignments with distant galaxies, planetary collisions, or young stars surrounded by debris could explain the findings.

The research utilized data from the NASA-led Wide-field Infrared Survey Explorer (WISE) and Europe’s ESA Gaia satellite, as well as The Two Micron All Sky Survey (2MASS), a collaboration between NASA’s Jet Propulsion Laboratory and the University of Massachusetts.

Interestingly, all Dyson sphere candidates are red dwarf stars, the most prevalent type of star in the Milky Way. Red dwarfs are smaller and dimmer than the Sun, complicating follow-up observations. It’s not yet clear if these stars host planets, but red dwarfs often have orbiting exoplanets, many of which could be in habitable zones.

Another study, conducted in March using the same datasets, also found anomalous infrared sources among 5 million stars.

Future Observations with the Webb Telescope

“We detected 53 suspect sources with unexplained anomalies, but not all are Dyson sphere candidates,” said Gabriella Contardo, a postdoctoral fellow leading the prior March study at Italy’s International School for Advanced Studies. She plans to compare her findings with Suazo’s models.

“Before claiming they’re Dyson spheres, all other potential explanations—such as debris disks or planetary collisions—must be ruled out scientifically. Doing so could advance other areas of astronomy as well,” Contardo added.

Both researchers agree that more investigation is essential, and NASA’s James Webb Space Telescope could potentially provide the needed insights—with its capacity to study these stars in greater detail. However, gaining access to Webb is highly competitive, so further study may take time.

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So, assuming Dyson spheres exist, what could they be used for? “If we tapped into the sun’s entire energy output, we could achieve extraordinary things,” Suazo remarked. “Perhaps even interstellar travel or moving our solar system…”

But the construction requirements make this an unlikely near-future achievement. “The necessary scale is unimaginable—Freeman Dyson even suggested dismantling Jupiter for raw materials,” Suazo explained.

Given their immense scale, Dyson spheres, if real, are probably rare.

“This study’s true significance lies in showing there aren’t vast numbers of Dyson spheres in our galaxy, despite some expectations that they would be the natural endpoint of advanced civilizations,” said co-author Jason Wright, a professor at Penn State University. “Suazo’s candidates are worthy of further investigation due to their uniqueness, with the James Webb Space Telescope potentially providing answers.”

A Legacy of Bold Theories

Dyson passed in 2020 without confirming the existence of his namesake spheres, although several ideas that shaped science still bear his name.

“As a young scholar, Dyson unified three rival quantum theories, ending decades of debate,” said William Press of UT Austin, explaining Dyson’s initial impact. “He then applied his brilliance to diverse fields—from cosmology to nuclear disarmament. By his end, he was acknowledged as a thought-provoking visionary.”

George Dyson echoe​d his father's wide-reaching influence. “Thanks to a short attention span and distaste for bureaucracy, he left his mark on physics, biology, engineering, literature, and beyond,” wrote George. “Many of his ideas were controversial, but he found value in being wrong rather than vague.”

The study’s unique approach to seeking intelligent life may hold promise, noted Tomotsugu Goto, an astronomer at Taiwan’s National Tsing Hua University. However, he added, “Contamination from circumstellar debris, which mimics Dyson signatures, remains a concern. Still, these rare candidates deserve deeper exploration.”

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In response to the May study, a paper released on May 23 argues that at least three of the seven Dyson sphere candidates might be misclassified and are instead “hot DOGs” (dust-shrouded galaxies). The remaining candidates may also have natural explanations.

Because this research touches on whether humanity is alone, it spans disciplines—sparking interest in fields such as philosophy and religion. “It could prompt new generations of scientists to explore these big questions,” said Zaza Osmanov, a SETI affiliate.

But Osmanov also pointed out that these infrared signals might be naturally created. “Before concluding an artificial origin, we need to exhaust all possible natural causes first. Further studies are required.”

If Freeman Dyson were still here, his son believes he would remain skeptical that these candidates represent alien technology. “Still, the discovery of astronomical phenomena beyond technology is precisely why he thought we should be searching in the first place,” George concluded.