Black holes may be invisible, but their influence shapes galaxies, modern technology and humanity's understanding of its own limits.

That was the message shared last week by Priyamvada Natarajan, a theoretical astrophysicist at Yale University, during a session at the World Economic Forum in Davos, Switzerland. Natarajan, whose research focuses on cosmology, gravitational lensing and black hole physics, traced how decades of theoretical work on black holes have transformed scientists' understanding of the universe and quietly underpin everyday technologies.

"Black holes have a very intimate relationship with each and every one of you," she told attendees. "You got here to Davos because the same equations that govern and explain black holes actually guide GPS."

Those equations come from Albert Einstein's theory of general relativity, which describes how mass and energy curve space and time. While black holes represent the theory's most extreme manifestation, the same mathematics is essential for calculating the subtle but measurable time differences experienced by satellites orbiting Earth.

Clocks aboard GPS satellites tick slightly faster than clocks on the ground because they are farther from Earth's gravitational pull. Without correcting for these relativistic effects, navigation errors would quickly accumulate, rendering GPS unreliable.

For much of the 20th century, however, black holes were regarded largely as mathematical curiosities — solutions to Einstein's equations with no clear observational evidence. That began to change in the 1960s, when astronomers identified Cygnus X-1, a powerful X-ray source that became the first widely accepted black hole candidate.

Astronomers now know that most large galaxies, including the Milky Way, host central supermassive black holes whose masses are closely linked to the properties of their host galaxies.

This revised picture, however, has introduced a new puzzle. Telescope observations show that supermassive black holes formed remarkably early in cosmic history, when the universe was only a few hundred million years old. Their sheer size and rapid growth challenge conventional models, which predict that the behemoths grow gradually from the remnants of collapsed, sun-like stars that slowly devour surrounding matter. The origin story of early supermassive black holes therefore remains one of astrophysics' most persistent questions.

Natarajan and her colleagues proposed a pathway for the universe's first black holes to form without requiring stars. The team suggested that under specific primordial conditions, pristine gas clouds — which would typically fragment and form stars — instead collapsed wholesale into massive black holes. These objects, known as direct-collapse black holes, would have contained tens of thousands to hundreds of thousands of times the mass of the sun within a few hundred million years after the Big Bang. Starting from such unusually large "seeds" helps resolve the timing problem posed by the existence of billion-solar-mass black holes less than a billion years after the universe formed.

Such a system, Natarajan said, would be an "overmassive black hole galaxy whose light is dominated not by the stars but by a black hole that is growing in its center."

Her team predicted more than a decade ago that these early black holes would leave distinctive observational signatures detectable by future observatories, including the James Webb Space Telescope (JWST) and the Chandra X-ray Observatory. In recent years, those predictions have begun to bear out.

One striking example is UHZ1, which reveals that accreting supermassive black holes were already in place just 470 million years after the Big Bang, with masses roughly 10 million times that of the sun.

Another is the so-called Infinity Galaxy, where JWST observations revealed two compact galactic nuclei surrounded by ring-like structures that likely formed via a head-on collision between two disk galaxies. Embedded between them lies a supermassive black hole, not at the center of either galaxy but suspended in a vast reservoir of gas, suggesting it formed through the direct collapse of dense, turbulent gas triggered by the collision.

"It's a thrill," said Natarajan, "to be around and, within one career lifetime, to have had the fortune of making predictions that were testable, have been tested, and have been validated."

Beyond their scientific impact, black holes also carry philosophical weight, she added.

"Studying cosmology in general and black holes specifically really instills a sense of cosmic humility," Natarajan said.

"Looking out into the universe," she added, "is uniquely allowing us to look back in time and piece together this beautiful cosmic story that we are part of."

Little Red Dots, mysterious objects discovered by the James Webb Space Telescope (JWST), could be nurseries for massive black holes that didn't form from collapsing stars, but instead emerged directly from vast gas clouds.

If this is the case, then it could solve not only the puzzle of the nature of Little Red Dots, but also another mystery uncovered by the JWST since it began operations in 2022. That is the discovery of a large population of supermassive black holes as early as 500 million years after the Big Bang.

This is problematic because the merger-driven process, thought to give rise to supermassive black holes with masses millions of even billions of times that of the sun, had previously been theorized to take at least a billion years to forge these cosmic titans that sit at the heart of large galaxies

That problem could be solved if supermassive black hole mergers begin with a "heavy seed", a direct collapse black hole, created when vastly overdense regions within primordial gas clouds collapse. This contrasts with a "light seed", formed when stars reach the end of their lives and explode as supernovae, leaving behind stellar-mass black holes

Not only would heavy seeds remove mass restrictions on the black holes that begin this merger process, but they would also allow it to get underway before the first generation of massive stars had even lived and died.

"All galaxies likely harbor a supermassive black hole at their centre, whose origin represents one of the frontier mysteries of modern astrophysics. One theoretical pathway to the formation of the heaviest black holes is that of direct collapse," research team leader Elia Cenci of the University of Geneva told Space.com. "In this scenario, black holes form following the collapse of a short-lived supermassive star that in turn forms from pristine gas that collapses at the centre of dark matter haloes that satisfy a number of stringent criteria. These criteria are mostly concerned with avoiding the formation of molecular hydrogen, which can efficiently cool the gas at high redshift, favoring the formation of smaller stars."

Cenci explained that Little Red Dots are weird sources of light that mostly emerged when the universe was less than a billion years old. Discovered through deep extragalactic surveys carried out with the JWST, they appear red and exceptionally compact, hence their name.

Little Red Dots are unusual for a number of other reasons, from the pattern of the light they emit, their spectra, to their physical properties, and the fact that they disappear early in the history of the 13.8 billion-year-old universe.

"A popular explanation for these objects is that we are looking at an abundant population of faint massive black holes of the early universe surrounded by very dense gas and stars that we would not been able to discover with previous instrumentation," Cenci said.

Cenci and colleagues connected Little Red Dots and direct collapse black holes while running high-resolution simulations of cosmic evolution in the early universe.

"Our results show that direct-collapse black holes that are newly formed naturally match the overall abundance and key physical characteristics inferred for the enigmatic Little Red Dots discovered with the JWST," Cenci said. "It is exciting to think that, if future studies confirm our proposed connection with direct-collapse black holes, Little Red Dots may represent the first direct observational evidence of the birth of the most massive black holes in the universe.

"For the first time, we would have real laboratories to understand the conditions under which giant black holes have formed."

Supermassive black holes could get a head start in Little Red Dots

Cenci explained that the advantage of direct collapse black holes is that they can act as so-called heavy seeds for black hole formation. This means that they can already be tens of thousands to a million times the mass of the sun when they form, unlike black holes formed via the death of stars, the mass of which is limited by the mass of the progenitor stars.

That provides a significant head start in growing supermassive black holes.

"Compared to lighter black hole seeds, they can grow more easily to the giant black holes that we observe in the short time available since the Big Bang, in astronomical terms at least," Cenci said.

The University of Geneva researcher also explained why direct collapse black holes and their nurseries aren't found in the local, modern-day universe, saying that the conditions needed include a lack of elements heavier than hydrogen and helium. Elements that are forged by stars and seeded in galaxies are released when these stars reach the end of their lives and explode as supernovae.

"In order to form direct collapse black holes, the gas should not form stars on its way to collapse in a monolithic fashion. Therefore, their 'nursery' environment must be pristine, not forming heavier molecules nor being polluted by the heavy elements produced by stellar evolution," Cenci said. "Practically speaking, these conditions are only possible in the early universe."

One of the most curious aspects of Little Red Dots is that they appear to vanish from the universe around 1.5 billion years after the Big Bang — or, as astronomers like Cenci describe it, at around redshift z~6. She believes this disappearance can be explained if Little Red Dots are hubs for direct collapse black hole formation.

"After z~6, the non-linear interplay of processes such as stellar evolution and feedback will make haloes hostile environments for the formation of direct collapse black holes, being more polluted with heavy elements and experiencing less intense inflows of gas that would favour the monolithic collapse scenario," Cenci said. "The decline in the population of newborn direct collapse black holes after z~6 is a natural consequence of the criteria determining where these objects can form."

Observational evidence confirming Little Red Dots as direct collapse black hole nurseries will require higher-resolution astronomical data and a more complete spectral coverage, Cenci explained. This would put additional constraints on the importance of the role black holes and stars play in Little Red Dots, as well as confirming the dynamics and physical state of their dense gas reservoirs. Until then, she and her team will continue to simulate conditions in the early universe to better understand this potential relationship.

"We are running a large suite of high-resolution simulations to test the implications of a number of different formation conditions for direct collapse black holes," "Our work will focus on understanding and characterising the population of direct collapse black holes in a cosmological context, and we will definitely be able to provide further insights on to what extent we can relate direct collapse black holes and Little Red Dots.

The team's research was published in the journal Monthly Notices of the Royal Astronomical Society.

Scientists may have solved a cosmic mystery that has been troubling them since the James Webb Space Telescope (JWST) began observations back in 2022.

When astronomers started looking back into the early days of the universe with the cutting-edge observatory, they discovered supermassive black holes that appear to have formed prior to the universe being 1 billion years old, something our current models of the cosmos can't explain But a new study has found that a black hole "feeding frenzy" may explain how these cosmic monsters were born so early in the universe's history.

"We found that the chaotic conditions that existed in the early universe triggered early, smaller black holes to grow into the super-massive black holes we see later, following a feeding frenzy which devoured material all around them," research leader Daxal Mehta of Maynooth University said in a statement. "We revealed, using state-of-the-art computer simulations, that the first generation of black holes – those born just a few hundred million years after the Big Bang grew incredibly fast, into tens of thousands of times the size of our sun."

Performing complex computer simulations, this team of researchers found that the turbulent and dense-gas-rich conditions in the first galaxies may have allowed black holes to enter into brief phases of mega-gluttony, exceeding a barrier known as the "Eddington limit." This limit determines how much material can fall to a body like a star or black hole before the radiation generated by that accretion pushes further matter away, emptying the central object's larder of gas and dust, thus cutting off its food supply.

Periods of super-consumption that defy this limit are known as "super-Eddington accretion" and serve as the missing link between black holes that form when massive stars die in supernova explosions and monstrous supermassive black holes.

Supermassive black holes are like six-foot toddlers

Supermassive black holes with masses millions or even billions of times that of the sun sit at the heart of all large galaxies in the modern 13.8 billion-year-old universe, which isn't troubling to explain at all, as they have had plenty of time to grow.

The issue is the discovery of supermassive black holes as early as 500 million years after the Big Bang, a population that the JWST has routinely been uncovering for the last three and a half years. That is because the merger and feeding processes that are thought to allow black holes to achieve supermassive status are thought to take at least 1 billion years.

"It's like seeing a family walking down the street, and they have two six-foot teenagers, but they also have with them a six-foot-tall toddler," research team member and Maynooth University scientist John Regan previously told Space.com. "That's a bit of a problem. How did the toddler get so tall? And it's the same for supermassive black holes in the universe. How did they get so massive so quickly?"

The team's simulations suggest that a super-Eddington feeding frenzy could have allowed the first generation of black holes to gorge on the dense gas of the early cosmos to reach masses of tens of thousands of times that of the sun. While that doesn't get us to supermassive black holes, it provides a significant head start on the merger process that would see black holes of increasing size collide and fuse together to birth an even more massive black hole.

"These tiny black holes were previously thought to be too small to grow into the behemoth black holes observed at the center of early galaxies," Mehta said. "What we have shown here is that these early black holes, while small, are capable of growing spectacularly fast, given the right conditions."

The team's research could help scientists determine whether early supermassive black holes started out as "light seeds," with ten to a few hundred times the mass of our sun, or as "heavy seeds," with as much as 100,000 times the mass of the sun. Previously, it had been theorized that only heavy seeds would be massive enough to facilitate the rapid growth of supermassive black holes.

"Now we're not so sure," Regan said. "Heavy seeds are somewhat more exotic and may need rare conditions to form. Our simulations show that your 'garden variety' stellar mass black holes can grow at extreme rates in the early universe."

The team's research doesn't just suggest a new avenue for supermassive black hole growth, but it also shows how important high-resolution simulations are in our investigation of the early cosmos.

"The early universe is much more chaotic and turbulent than we expected, with a much larger population of massive black holes than we anticipated, too," Regan said.

As for collecting evidence of this theory, that may be a job not for the JWST or any other traditional astronomical device, but for instruments designed to detect the tiny ripples in space known as gravitational waves that mergers such as this radiate. Of particular importance could be the first space-based gravitational wave detector, the Laser Interferometer Space Antenna (LISA), a joint European Space Agency/ NASA mission set to launch in 2035.

"Future gravitational wave observations from that mission may be able to detect the mergers of these tiny, early, rapidly growing baby black holes," Regan concluded.

The team's research was published on Wednesday (Jan. 21) in the journal Nature Astronomy.

Using the James Webb Space Telescope (JWST), astronomers have discovered an oddball galaxy, dubbed the Infinity Galaxy, that could be host to a "direct collapse black hole." That is, a black hole originally created directly from a vast cloud of collapsing gas and dust rather than a dying star.

The Infinity Galaxy gets its name from the fact that its shape resembles an infinity symbol (a sideways 8) with two red lobes or "nuclei." This shape is thought to have arisen because the Infinity Galaxy was formed as two disk galaxies engaged in a head-on collision.

What makes this highly unusual is the fact that this black hole sits between the two colliding galaxies in a vast cloud of gas, rather than in either respective nucleus. From its perch between these galaxies, the black hole now feeds greedily on that gas, but researchers think that same cloud also once birthed it. That would make this the first observational evidence of the direct collapse pathway of black hole birth.

The researchers behind these findings uncovered the Infinity Galaxy while examining images from the JWST's 255-hour treasury COSMOS-Web survey. In addition to the suspected direct collapse black hole that sits between the colliding galaxies, the team found that each nucleus of those galaxies also contains a supermassive black hole!

"Everything is unusual about this galaxy. Not only does it look very strange, but it also has this supermassive black hole that's pulling a lot of material in," team leader and Yale University researcher Pieter van Dokkum said in a statement. "The biggest surprise of all was that the black hole was not located inside either of the two nuclei but in the middle.

"We asked ourselves: How can we make sense of this?"

van Dokkum explained that finding a black hole not in the nucleus of a massive galaxy isn't, in itself, unusual. What is strange is the question of how that black hole got there.

"It likely didn't just arrive there, but instead it formed there," van Dokkum said. "And pretty recently. In other words, we think we're witnessing the birth of a supermassive black hole – something that has never been seen before."

This discovery could solve an intriguing mystery regarding the observation of supermassive black holes with masses millions or billions of times that of the sun, less than 1 billion years after the Big Bang.

Black holes could skip stellar deaths and supernovas

Since it began operating three years ago, the JWST has delivered something of a conundrum to cosmologists; observations that show supermassive black holes seem common as early as 500 million years after the Big Bang.

That's a problem because it was previously proposed that supermassive black holes form through successive mergers of smaller black holes. However, beginning this process with so-called stellar-mass black holes would require waiting for the first generation of stars to form, live their lives, then collapse in supernova explosions. The resulting black holes would have to undergo a series of mergers and periods of intense feeding upon interstellar gas and dust.

This process would take at least a billion years to "grow" a black hole to supermassive status. Thus, seeing a multitude of supermassive black holes before the universe was 1 billion years old is problematic.

That is, unless these bodies got a head start by skipping the stellar life and birth stage of this process.

"How supermassive black holes formed is a long-standing question. There are two main theories, called 'light seeds' and 'heavy seeds.' In the light seed theory, you start with small black holes formed when a star's core collapses and the star explodes as a supernova," van Dokkum explained. "That might result in a black hole weighing up to about 1,000 suns. You form a lot of them in a small space, and they merge over time to become a much more massive black hole."

As mentioned above, the problem with that is the time this process would take and the JWST's discovery of incredibly massive black holes at early stages of our 13.8 billion-year-old universe.

Black holes could have heavy seeds

Alternatively, the heavy seed theory sees supermassive black hole growth kickstarted with a much larger black hole, maybe up to one million times the mass of the sun. This forms directly from the collapse of a large gas cloud.

"You immediately form a giant black hole, so it's much quicker. However, the problem with forming a black hole out of a gas cloud is that gas clouds like to form stars as they collapse rather than a black hole, so you have to find some way of preventing that. It's not clear that this direct-collapse process could work in practice," van Dokkum said. "By looking at the data from the Infinity Galaxy, we think we've pieced together a story of how this could have happened here."

The researchers suggest that as the two disk galaxies collided, a ring structure of stars, visible in the JWST image, was formed. During this collision, gas within these two galaxies would have been shocked and compressed. They think this compression may have been so extreme that it formed a "dense knot" in the gas, which then collapsed into a black hole.

As van Dokkum explained, there is a wealth of circumstantial evidence for this formation channel for the black hole in the Infinity Galaxy.

"We observe a large swath of ionized gas, specifically hydrogen that has been stripped of its electrons, that's right in the middle between the two nuclei, surrounding the supermassive black hole," he continued. "We also know that the black hole is actively growing – we see evidence of that in X-rays from NASA's Chandra X-ray Observatory and radio from the Very Large Array. Nevertheless, the question is, did it form there?"

There are two possible explanations that don't involve a direct collapse black hole forming at the intersection of these merged galaxies.

"First, it could be a runaway black hole that got ejected from a galaxy and just happens to be passing through," van Dokkum said. "Second, it could be a black hole at the center of a third galaxy in the same location on the sky. If it were in a third galaxy, we would expect to see the surrounding galaxy unless it were a faint dwarf galaxy. However, dwarf galaxies don't tend to host giant black holes.

"If the black hole were a runaway, or if it were in an unrelated galaxy, we would expect it to have a very different velocity from the gas in the Infinity Galaxy."

To test this, the team intends to measure the velocity of the gas and the velocity of the black hole and compare them. Should those velocities be close, within around 30 miles per second (50 kilometers per second), then van Dokkum asserts that it will be hard to argue that the black hole is not formed from that gas.

"Our preliminary results are exciting. First, the presence of an extended distribution of ionized gas between the two nuclei is confirmed. Second, the black hole is beautifully in the middle of the velocity distribution of this surrounding gas, as expected if it formed there. This is the key result that we were after!" van Dokkum continued. "Third, as an unexpected bonus, it turns out that both galaxy nuclei also have an active supermassive black hole."

Though the team can't say definitively that they discovered a direct collapse black hole, they can state with confidence that this JWST data strengthens the case for this being a newborn black hole, while eliminating some of the counter-explanations to the direct collapse pathway.

"This system has three confirmed active black holes: two very massive ones in both of the galaxy nuclei, and the one in between them that might have formed there," van Dokkum said. "We will continue to pore through the data and investigate these possibilities."

A bright galaxy in the early universe likely contains a mysterious kind of black hole that had previously existed only in theory, a new study suggests.

This probable "direct-collapse" black hole may help explain how supermassive black holes — the light-gobbling behemoths that lurk at the hearts of most, if not all, galaxies — got their start, researchers said.

"The special aspect of this [direct-collapse] process is that it leads to the formation of a very massive 'seed' black hole in one go," study co-author Avi Loeb, chair of the astronomy department at Harvard University, told Space.com via email. "It is difficult to make such a giant black hole over such a short time if they start from low-mass seeds." [Images: Black Holes of the Universe]

Death by gluttony

When a massive star reaches the end of its lifetime, it can collapse inward on itself to form a black hole. These dense objects then grow by feeding on surrounding gas and dust, but the process can take time. 

Indeed, it probably takes quite a while for such a small seed to grow into a supermassive black hole, which can contain billions of times more mass than the sun, scientists say. This poses a puzzle: Where, then, did the supermassive black holes in the early universe come from?

Some of these monsters existed only 750 million years after the Big Bang that created the universe, Loeb said. (Scientists know this because they have spotted quasars — incredibly bright galactic cores powered by supermassive black holes — of this vintage.)

"It is difficult to make such a giant black hole over such a short time if they start from low-mass seeds," Loeb said.

In 2003, Loeb and Volker Bromm of the University of Texas at Austin (UT Austin) — also a co-author of the new study — theorized that clouds of dust and gas in the early universe were so hot that they failed to fragment into multiple clumps of thousands of stars. Instead, such clouds likely created just a single massive star at the center, roughly 1 million times larger than "normal" stars, Loeb said.

Such gigantic stars would quickly consume all of the nearby gas and dust. Overeating would lead to a rapid demise; these stars would last only a few million years before collapsing into midsized black holes that could continue to feed, ultimately growing into the giants that lie at the centers of galaxies.

To stay so superhot, the gas at the heart of this process would need to be almost purely hydrogen and helium, without "heavier" elements to help cool it down. Since heavy elements are produced in the hearts of stars and then released during a supernova, such "direct-collapse black holes" could only form in the early universe, the researchers said. [The Universe: Big Bang to Now in 10 Easy Steps]

But there hadn't been much evidence for this idea — until now.

From prediction to reality

Last year, astronomers spotted a strange signal from a galaxy known as CR7, one of the most luminous objects in the early universe. Although the galaxy showed signs of temperatures greater than 180,000 degrees Fahrenheit (100,000 degrees Celsius) and signatures of helium atoms gaining and losing electrons — a process known as ionization — there were no signs of other elements.

"That makes the galaxy that we have discovered really unique, and ticks all the boxes for predictions for both first-generation stars or a direct-collapse black hole," David Sobral, an astrophysicist at the University of Lisbon in Portugal, told Space.com.

Sobral led the team of astronomers that identified irregularities in CR7 last year and other similar galaxiesmore recently. In their paper, they argued that, while CR7 could contain a direct-collapse black hole, the unusual signal favored a cluster of the universe's first stars.

"Regardless, the actual material — pristine gas — to make either first-generation stars or a direct-collapse black hole is essentially the same, and it is extremely exciting to finally start asking actual physical questions about the nature of the very early galaxies," Sobral said. "This goes way beyond the traditional approach of simply counting distant galaxies."

Sobral and other scientists will continue to observe CR7, with instruments such as NASA's Hubble Space Telescope and the Atacama Large Millimeter/submillimeter Array in Chile. But other research teams are investigating the galaxy's origin and evolution via computer modeling and other work.

Fabio Pacucci, a Ph.D. student at Scuola Normale Superiore in Italy, was part of one such team, whose research argued for the black-hole theory in a paper last year. But those researchers' observations of CR7 weren't definitive.

"Unfortunately, we do not see any X-ray emission from this source, which would be a smoking gun to say that it is a black hole," Pacucci said.

That's where Loeb and Volker come in. They're members of another research team, led by Aaron Smith of UT Austin, that sought to solve the mystery.

Smith and his colleagues developed what Smith called "a novel code" to simulate both the black-hole and the first-star scenarios using a supercomputer at UT Austin. The star scenario "spectacularly failed," Smith said in a statement, while the direct-collapse model held up.

"The evidence [for a black hole] is conclusive," Loeb told Space.com.

After predicting the existence of direct-collapse black holes more than a decade ago, Loeb is excited to see them confirmed by observations.

"It feels good to come up with an idea about how nature might work, but it is exhilarating to find out that nature really behaves the way you thought it does," Loeb said. "The experience is as rewarding as getting love back from a person you love."

Smith and his colleagues published their results last week in the journal Monthly Notices of the Royal Astronomical Society.

Follow Nola Taylor Redd on Twitter @NolaTRedd or Google+. Follow us at @Spacedotcom, Facebook or Google+. Originally published on Space.com.