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In the last couple of decades, it’s become increasingly clear that massive galaxies like our own Milky Way host supermassive black holes (SMBHs) in their centres. How they became so massive and how they affect their surroundings are active questions in astronomy. Astronomers working with the James Webb Space Telescope have discovered an SMBH in the early Universe that is accreting mass at a very low rate, even though the black hole is extremely massive compared to its host galaxy.

What’s going on with this SMBH, and what does it tell astronomers about the growth of these gargantuan black holes?

The black hole, named GN-1001830, was discovered as part of JADES (JWST Advanced Deep Extragalactic Survey). It is one of the most massive SMBHs discovered by the JWST in the early Universe. While most present-day SMBHs account for about 0.1 % of the mass of their host galaxies, this one accounts for about 40% of its host galaxy’s mass.

The puzzling thing is that GN-1001830 is consuming the gas it needs to grow at a very low rate and is basically dormant. Is it taking a break? Did it experience accelerated bursts of growth in the past?

The findings are in new research published in Nature titled “A dormant overmassive black hole in the early Universe.” The lead author is Ignas Juodžbalis. Juodžbalis is a grad student at the Kavli Institute for Cosmology at the University of Cambridge.

“The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

Ignas Juodžbalis, Kavli Institute for Cosmology, University of Cambridge

The JWST has found many SMBHs already in place, only a few hundred million years after the Big Bang. Some of them are overmassive yet dormant, like GN-1001830. Researchers have developed multiple different models to explain them.

This image shows the JWST Advanced Deep Extragalactic Survey (JADES) region of study. It’s in the same region as the Hubble’s Ultra Deep Field. Image Credit:

One model is the ‘heavy seed‘ model, where primordial gas clouds directly collapsed into black holes that grew to become SMBHs. Another model proposes light seeds that experience powerful bursts of accretion. Both models hold promise, but there’s no certainty. “Yet, current datasets are unable to differentiate between these various scenarios,” Juodžbalis and his co-authors write in their research article.

These overmassive black holes that appear to be dormant are testing astrophysicists’ understanding of how SMBHs form and grow. It’s likely that they go through bursts of growth, and in between those bursts, they lie dormant. One of the problems is that it’s very difficult to spot an SMBH that isn’t actively accreting gas. They’re visible when accreting because the accretion disk heats up and emits light.

This one was only spotted because it’s so massive.

“Even though this black hole is dormant, its enormous size made it possible for us to detect,” said lead author Juodžbalis. “Its dormant state allowed us to learn about the mass of the host galaxy as well. The early universe managed to produce some absolute monsters, even in relatively tiny galaxies.”

The Eddington Limit (also known as Eddington Luminosity) is an important factor in the growth of SMBHs. It is a theoretical upper limit on the mass and luminosity of stellar objects, explaining the luminosity we observe in accreting black holes. The Eddington limit is reached when the outward pressure of radiation exceeds the object’s gravitational power, and it can’t accrete more matter. Objects can also exceed this limit, and when that happens, it’s called Super Eddington accretion. Some researchers suggest that Super Eddington accretion was more common in the early Universe and that it explains not only this overmassive black hole but all of the other massive black holes the JWST has discovered in the Universe’s early times.

“It’s possible that black holes are ‘born big’, which could explain why Webb has spotted huge black holes in the early universe,” said co-author Professor Roberto Maiolino from the Kavli Institute and Cambridge’s Cavendish Laboratory. “But another possibility is they go through periods of hyperactivity, followed by long periods of dormancy.”

“It’s likely that the vast majority of black holes out there are in this dormant state.”

Professor Roberto Maiolino, Kavli Institute and Cambridge’s Cavendish Laboratory

The research is based on the detection of broad H-alpha emissions from the SMBH. Those emissions showed that the overmassive black hole has an estimated mass of approximately 4 × 10? (40 million) solar masses. That’s extremely massive for an object only about 800 million years after the Big Bang. For comparison, Sagittarius A*, the SMBH in the Milky Way, has an estimated mass of about 4.3 million solar masses.

The SMBH in question is one of the most overmassive objects the JWST has found. Its mass is almost 50% of the stellar mass of its host galaxy. That’s about 1,000 times more massive than the relation in local galaxies.

The researchers conducted computer simulations to probe the issue. Their research suggests that the SMBH’s periods of hyperactivity likely exceed the Eddington Limit. The SMBH’s long periods of dormancy and inactivity can last for 100 million years, where the accretion rate is only 0.02 times the Eddington Limit, and are punctuated by episodes of Super Eddington accretion that last for about five or ten million years.

“It sounds counterintuitive to explain a dormant black hole with periods of hyperactivity, but these short bursts allow it to grow quickly while spending most of its time napping,” said Maiolino.

Since these SMBHs spend far more time dormant than they do active, they’re more likely to be spotted during dormancy. However, they’re far more difficult to spot when they’re not actively accreting and emitting radiation from their accretion rings. That’s part of what makes this detection so valuable.

These results are agnostic when it comes to heavy or light seeds. Instead, they’re all about Super Eddington episodes. “It is tempting to speculate that our result favours light seed models. However, the same result would also hold if the models had started with heavy seeds. The key feature that allows the properties of GN-1001830 to be matched is the fact that accretion goes through super-Eddington phases, regardless of the seeding mechanism,” the authors explain.

This set of illustrations explains how a large black hole can form from the direct collapse of a massive cloud of gas a few hundred million years after the Big Bang. Panel #1 shows a massive gas cloud and a galaxy moving towards each other. If the formation of stars in the gas cloud is stalled by radiation from the incoming galaxy – preventing it from forming a new galaxy — the gas can instead be driven to collapse and form a disk and black hole. Panels #2 and #3 show the beginning of this gas collapse in the center of the cloud. A small black hole forms in the center of the disk (panel #4), and the black hole and disk then continue to grow (panel #5). This massive black hole “seed” and its disk then merge with the galaxy shown in panel #1. For a period of time, the black hole is unusually massive compared to the mass of the stars in the galaxy, making it an Overmassive Black Hole (panel #6). Stars and gas from the galaxy are pulled in by the black hole, causing the black hole and disk to grow even larger. Image Credit: NASA/STScI/Lea Hustak

“This was the first result I had as part of my PhD, and it took me a little while to appreciate just how remarkable it was,” said Juodžbalis. “It wasn’t until I started speaking with my colleagues on the theoretical side of astronomy that I was able to see the true significance of this black hole.”

“It’s likely that the vast majority of black holes out there are in this dormant state—I’m surprised we found this one—but I’m excited to think that there are so many more we could find,” said Maiolino.

The post An Early Supermassive Black Hole Took a Little Break Between Feasts appeared first on Universe Today.

Wastewater treatment plants in the US may discharge enough “forever chemicals” to raise concentrations in drinking water above the safe limit for millions of people

Lead records from Arctic glaciers indicate that people all over Europe would have been affected by pollution from metal smelting during the Roman era

Scientists have developed an advanced swarm navigation algorithm for cyborg insects that prevents them from becoming stuck while navigating challenging terrain. The new algorithm represents a significant advance in swarm robotics. It could pave the way for applications in disaster relief, search-and-rescue missions, and infrastructure inspection. Cyborg insects are real insects equipped with tiny electronic devices on their backs -- consisting of various sensors like optical and infrared cameras, a battery, and an antenna for communication -- that allow their movements to be remotely controlled for specific tasks.

Scientists have developed an advanced swarm navigation algorithm for cyborg insects that prevents them from becoming stuck while navigating challenging terrain. The new algorithm represents a significant advance in swarm robotics. It could pave the way for applications in disaster relief, search-and-rescue missions, and infrastructure inspection. Cyborg insects are real insects equipped with tiny electronic devices on their backs -- consisting of various sensors like optical and infrared cameras, a battery, and an antenna for communication -- that allow their movements to be remotely controlled for specific tasks.

Among the hundreds of thousands of chemical compounds produced by plants, some may hold the key to treating human ailments and diseases. But recreating these complex, naturally occurring molecules in the lab often requires a time-consuming and tedious trial-and-error process. Now, chemists have shown how new computational tools can help them create complex natural compounds in a faster and more streamlined way.

A recent study highlights a groundbreaking development in foldable molecular paths within solid-state frameworks, illuminating their potential for dynamic pore control and transformative applications in molecular metamaterials.

Collaborative work by amateur and professional astronomers has helped to resolve a long-standing misunderstanding about the composition of Jupiter's clouds. Instead of being formed of ammonia ice -- the conventional view -- it now appears they are likely to be composed of ammonium hydrosulphide mixed with smog.

Engineers have utilized quantum sensors to realize a groundbreaking variation of nuclear quadrupolar resonance (NQR) spectroscopy, a technique traditionally used to detect drugs and explosives or analyze pharmaceuticals. The new method is so precise that it can detect the NQR signals from individual atoms -- a feat once thought unattainable. This unprecedented sensitivity opens the door to breakthroughs in fields like drug development, where understanding molecular interactions at the atomic level is critical.

Engineers have utilized quantum sensors to realize a groundbreaking variation of nuclear quadrupolar resonance (NQR) spectroscopy, a technique traditionally used to detect drugs and explosives or analyze pharmaceuticals. The new method is so precise that it can detect the NQR signals from individual atoms -- a feat once thought unattainable. This unprecedented sensitivity opens the door to breakthroughs in fields like drug development, where understanding molecular interactions at the atomic level is critical.

Researchers have developed a way of detecting circulating tumor cells in the bloodstream of pancreatic cancer and lung cancer patients.

Comet C/2024 G3 ATLAS may put on a quick show this month.

Comet G3 ATLAS on December 30th. Credit: Alan C. Tough

What ‘may’ be the best anticipated comet of 2025 is coming right up. Right now, there’s only one comet with real potential to reach naked eye visibility in 2025: Comet C/2024 G3 ATLAS. This comet reaches perihelion at 0.094 Astronomical Units (AU, 8.7 million miles or 14 million kilometers, interior to the orbit of Mercury) from the Sun on January 13th, and ‘may’ top -1st magnitude or brighter. At magnitude +4 in late December, Comet G3 ATLAS could become a fine object low in the dawn sky for southern hemisphere observers… if (a big ‘if) it holds together and performs as expected.

The comet actually produced an outburst over the first weekend of 2025, jumping from magnitude +4 to +1 (a sixteen-fold increase in brightness in a few short days). This could be a harbinger for good (or bad) things to come shortly.

“The comet has had an outburst in the last few days,” Nicolas Lefaudeux told Universe Today. “If the outburst is linked to disintegration, there would probably be nothing to see after perihelion. If the outburst is linked to new active areas or splitting of a large nucleus, the display could be much better than in the simulations.”

The prospects for the tail of Comet G3 ATLAS, around perihelion. Credit: Nicolas Lefaudeux

A recent International Astronomical Union Central Bureau for Astronomical Telegrams message suggests an optimistic peak of -3rd magnitude near perihelion post outburst, ‘if’ the comet holds together.

Comet G3 ATLAS low at dawn versus Mercury on January 11th. Credit: Starry Night. The Discovery

The comet was discovered by the Asteroid Terrestrial-Impact Last Alert System (ATLAS) survey as a +19th magnitude object in the southern hemisphere constellation Apus the Bee on the night of April 5th, 2024.

The orbital path for Comet G3 ATLAS through the inner solar system. Credit: NASA/JPL

The orbital period for this one is around 160,000 years. It’s unclear if Comet G3 ATLAS is a first-time visitor to the inner solar system, or a new denizen coming from the distant Oort Cloud. The last time the comet swung by the inner solar system (assuming it has done so in the past), wearing clothing was the hot new thing among our homo sapiens ancestors.

Comet G3 ATLAS from January 2nd. Credit: iTelescope/Tara Prystavski. Comet G3 at Perihelion: Perish or Prosper?

Prospects for seeing this comet will be tricky. Unlike last year’s Comet C/2023 A3 Tsuchinshan-ATLAS which unfurled a magnificent tail for its evening apparition, G3 ATLAS will be a timid one both before and after perihelion, as it departs our solar neighborhood hugging the southern horizon in the dusk sky.

Comet G3 ATLAS, post perihelion on January 15th at dusk. Credit: Starry Night.

A daytime comet could be in the offing if G3 ATLAS over-performs at perihelion… but it will be a challenging view, very near the Sun. Be sure to block the dangerous glare of the Sun fully out of view behind a building or structure if you attempt to spot the comet in daylight. Like A3 T-ATLAS, the joint NASA/ESA SOHO observatory will see the comet near perihelion crossing through its LASCO C3 viewer.

Comet G3 ATLAS versus SOHO through the month of January. Credit: Starry Night. Best Bets For Comet G3 ATLAS

Perihelion on Monday, January 13th, 2025 will see the comet just four degrees from the Sun. The comet also makes its closest approach to Earth at 0.938 AU distant on the same date. The comet ‘could’ reach -4th magnitude (about as bright as Venus) around the same time… if it manages to hold together at perihelion.

Here’s a recent remote telescope image of the comet taken from late December by Nick James:

Comet G3 ATLAS from December 15th. Credit: Nick James/BAA Comet Section/iTelescope.

Comet G3 ATLAS has been elusive thus far. The comet has been bashful, skimming just five degrees above the dawn horizon leading up to perihelion in early January for northern hemisphere observers. The comet reemerges low to the west after dusk, but again, folks up north only get a very brief view 5-10 degrees above the horizon at dusk, as the comet runs parallel with the horizon southward. As usually seems to be the case with comets, the southern hemisphere gets the better view.

Here’s a blow-by-blow of what to expect in the coming months from the comet. (Note that ‘passes near,’ denotes a conjunction of a degree or less):

January

6-Near the Lagoon Nebula (Messier 8)

7-Near the globular cluster (Messier 28)

8-Crosses the ecliptic plane northward

11-Enters SOHO LASCO C3 view

13-At perihelion, less than 5 degrees from the Sun

14-Crosses into the constellation Capricornus

15-Exits SOHO LASCO C3 view, and crosses the ecliptic plane southward

21-Nicks the corner of the constellation Microscopium

22-Crosses into the constellation Piscis Austrinus

The light curve for comet G3 ATLAS. Adapted from Seichii Yoshida’s Weekly Information About Bright Comets. February

1-May drop back down below +6th magnitude

6-Crosses into the constellation Grus

21-Nicks the corner of the constellation Sculptor

25-Crosses into the constellation Phoenix

March

March 1st: May drop back down below +10th magnitude.

Observing and imaging the comet will be challenging, owing to two main factors: first, it will never really leave the low-contrast, twilight sky for northern hemisphere observers. Second, said quoted magnitude for a comet gets ‘smeared out’ over its apparent surface area, knocking the comet’s apparent brightness down a notch or two. We can hope that Comet G3 ATLAS is an over-performer in this regard. My strategy is to find high ground to observe from and the lowest, flattest horizon (like, say, the ocean as seen from a beach) that you can find, and sweep the horizon at low power with binoculars for the fuzzball of a comet.

Good luck and clear skies on this, the first comet quest of 2025.

The post Will Comet G3 ATLAS Perform at Perihelion? appeared first on Universe Today.

Throat vibrations made by people who find it difficult to speak, such as after a stroke, can be analysed by AI and used to create sentences

One powerful way to study the galaxies is to study individual stars. By looking at the ages, types, and distribution of stars in the Milky Way, we’ve captured a detailed snapshot of how our galaxy formed and evolved. The only problem with this approach is that we can only do this for a handful of galaxies. Even with the most powerful telescopes, we can only see individual stars in the Milky Way and nearby galaxies such as Andromeda. For galaxies billions of light years away, individual stars blur together, and the best we can do is observe the overall spectra of galaxies, not individual stars. But thanks to a chance alignment, we can now observe dozens of stars in a galaxy so distant we see it at a time when the Universe was half its present age.

The results are published in Nature Astronomy, and they focus on JWST observations of a cluster of galaxies known as Abell 370. This galactic cluster is famous because it acts as a gravitational lens for more distant galaxies behind it. You can see them as arcs of light in the image above. One prominent arc, highlighted in the image, is known as The Dragon. It is made up of the lensed and magnified images of several galaxies, the light of which has traveled 5 to 7 billion years to reach us.

The Dragon has been studied before using observations from the Hubble Space Telescope, and from these studies astronomers have been able to see a handful of blue supergiant stars, which are the largest and brightest main sequence stars. But identifying individual stars is notoriously difficult. In this new study, the team used JWST observations of The Dragon from 2022 and 2023. Since the Webb is capable of capturing high-resolution images in the infrared, it’s perfectly suited to study the spectra of redshifted stars in the cosmic middle age.

Individual stars identified in the Dragon arc in 2022 and 2023. Credit: Yoshinobu Fudamoto, et al

But even the Webb would be hard-pressed to identify more than a few bright stars within The Dragon, were it not for a second effect of gravitational lensing known as microlensing. Within the distant galaxy, two stars can line up just so, and the more distant star is gravitationally magnified for a short time, like a flare. This allows astronomers to study the spectra of the distant star. So a galaxy from 7 billion years ago is lensed into a bright arc of light by the Abell 370 cluster, and within that galaxy stars are further microlensed by a stellar alignment.

The team was able to identify more than 40 microlensing events, and was therefore able to capture the spectra of more than 40 individual stars in the distant galaxy. Based on the spectra, these stars are red supergiants similar to Betelgeuse. The study shows that microlensing events such as these are common, so we should be able to see lots more stars in this distant galaxy in the future.

We know a great deal about red supergiants in the Milky Way. Since they are dying stars, red giants play a significant role in enriching the available elements in a galaxy, which determines things such as the formation of stars and even life. But by studying these distant red giants, we will be able to see how they impacted the chemical diversity of younger galaxies. It could even help us understand what the Milky Way was like when the Sun and Earth began to form.

Reference: Yoshinobu Fudamoto, et al. “Identification of more than 40 gravitationally magnified stars in a galaxy at redshift 0.725.” Nature Astronomy (2025).

The post A Dragon Reveals Individual Stars From A Time When the Universe Was Half Its Present Age appeared first on Universe Today.

Many people decide to give up alcohol during January. But is this actually helpful in the long-term and are there better, easier ways to change our drinking habits, asks Ian Hamilton

Simulations suggest Pluto and its largest moon may have gently stuck together for a few hours before Charon settled into a stable orbit around the dwarf planet

A velvet ant sting is like “hot oil spilling over your hand” – now, scientists have identified molecules in its venom that let it deliver excruciating pain to a variety of other animals

The many-worlds interpretation of quantum mechanics invokes alternative realities to keep everything in balance. Has solving a century-old paradox now undermined their existence?

Getting a spacecraft to another star is a monumental challenge. However, that doesn’t stop people from working on it. The most visible groups currently doing so are Breakthrough Starshot and the Tau Zero Foundation, both of whom focus on a very particular type of propulsion-beamed power. A paper from the Chairman of Tau Zero’s board, Jeffrey Greason, and Gerrit Bruhaug, a physicist at Los Alamos National Laboratory who specializes in laser physics, takes a look at the physics of one such beaming technology – a relativistic electron beam – how it might be used to push a spacecraft to another star.

There are plenty of considerations when designing this type of mission. One of the biggest of them (literally) is how heavy the spacecraft is. Breakthrough Starshot focuses on a tiny design with gigantic solar “wings” that would allow them to ride a beam of light to Alpha Centauri. However, for practical purposes, a probe that small will be able to gather little to no actual information once it arrives there—it’s more of a feat of engineering rather than an actual scientific mission.

The paper, on the other hand, looks at probe sizes up to about 1000kg—about the size of the Voyager probes built in the 1970s. Obviously, with more advanced technology, it would be possible to fit a lot more sensors and controls on them than what those systems had. But pushing such a large probe with a beam requires another design consideration—what type of beam?

Fraser discusses how we might get to Alpha Centauri.

Breakthrough Starshot is planning a laser beam, probably in the visible spectrum, that will push directly on light sails attached to the probe. However, given the current state of optical technology, this beam could only push effectively on the probe for around .1 AU of its journey, which totals more than 277,000 AU to Alpha Centauri. Even that minuscule amount of time might be enough to get a probe up to a respectable interstellar speed, but only if it’s tiny and the laser beam doesn’t fry it.

At most, the laser would need to be turned on for only a short period of time to accelerate the probe to its cruising speed. However, the authors of the paper take a different approach. Instead of providing power for only a brief period of time, why not do so over a longer period? This would allow more force to build up and allow a much beefier probe to travel at a respectable percentage of the speed of light. 

There are plenty of challenges with that kind of design as well. First would be beam spread—at distances more than 10 times the distance from the Sun to the EartSunhow would such a beam be coherent enough to provide any meaningful power? Most of the paper goes into detail about this, focusing on relativistic electron beams. This mission concept, known as Sunbeam, would use just such a beam.

Fraser discusses another interstellar probe – Project Dragonfly

Utilizing electrons traveling at such high speeds has a couple of advantages. First, it’s relatively easy to speed electrons up to around the speed of light—at least compared to other particles. However, since they all share the same negative charge, they will likely repel each other, diminishing the beam’s effective push.

That is not as much of an issue at relativistic speeds due to a phenomenon discovered in particle accelerators known as relativistic pinch. Essentially, due to the time dilation of traveling at relativistic speeds, there isn’t enough relative time experienced by the electrons to start pushing each other apart to any meaningful degree.

Calculations in the paper show that such a beam could provide power out to 100 or even 1000 AU, well past the point where any other known propulsion system would be able to have an impact. It also shows that, at the end of the beam powering period, a 1,000kg probe could be moving as fast as 10% of the speed of light – allowing it to reach Alpha Centauri in a little over 40 years.

Multi-stage ships could be the key to interstellar travel – as Fraser discusses.

There are plenty of challenges to overcome for that to happen, though – one of which is how to get that much power formed into a beam in the first place. The farther a probe is from the beam’s source, the more power is required to transmit the same force. Estimates range up to 19 gigaelectron volts for a probe out at 100 AU, a pretty high energy beam, though well within our technology grasp, as the Large Hadron Collider can form beams with orders of magnitude more energy.

To capture that energy in space, the authors suggest using a tool that doesn’t yet exist, but at least in theory could – a solar statite. This platform would sit above the Sun’s surface, using a combination of force from the push of light from the star and a magnetic field that uses the magnetic particles the Sun emits to keep it from falling into the Sun’s gravity well. It would sit as close as the Parker Solar Probe’s closest approach to the Sun, which means that, at least in theory, we can build materials to withstand that heat. 

The beam forming itself would happen behind a massive sun shield, which would allow it to operate in a relatively cool, stable environment and also be able to stay on station for the days to weeks required to push the 1000kg probe out as far as it would go. That is the reason for using a statute rather than an orbit—it could stay stationary relative to the probe and not have to worry about being occluded by the Earth or the Sun.

Fraser discusses interstellar travel with Avi Loeb, a Harvard professor and expert in interstellar travel.

All this so far is still in the realm of science fiction, which is why the authors met in the first place – on the ToughSF Discord server, where sci-fi enthusiasts congregate. But, at least in theory, it shows that it is possible to push a scientifically useful probe to Alpha Centauri within a human lifetime with minimal advances to existing technology.

Learn More:
Greason & Bruhaug – Sunbeam: Near-Sun Statites as Beam Platforms for Beam-Driven Rockets
UT – Researchers are Working on a Tractor Beam System for Space
UT – A Novel Propulsion System Would Hurl Hypervelocity Pellets at a Spacecraft to Speed it up
UT – A Concentrated Beam of Particles and Photons Could Push Us to Proxima Centauri

Lead Image:
Depiction of the electro beam statite used in the study.
Credit – Greason & Bruhaug

The post Pushing A Probe To Alpha Centauri Using A Relativistic Electron Beam appeared first on Universe Today.

How close are we to having fusion reactors actually sending electric power to the grid? This is a huge and complicated question, and one with massive implications for our civilization. I think we are still at the point where we cannot count on fusion reactors coming online anytime soon, but progress has been steady and in some ways we are getting tatalizingly close.

One company, Commonwealth Fusion Systems, claims it will have completed a fusion reactor capable of producing net energy by “the early 2030’s”. A working grid-scale fusion reactor within 10 years seems really optimistic, but there are reasons not to dismiss this claim entirely out of hand. After doing a deep dive my take is that the 2040’s or even 2050’s is a safer bet, but this may be the fusion design that crosses the finish line.

Let’s first give the background and reasons for optimism. I have written about fusion many times over the years. The basic idea is to fuse lighter elements into heavier elements, which is what fuels stars, in order to release excess energy. This process releases a lot of energy, much more than fission or any chemical process. In terms of just the physics, the best elements to fuse are one deuterium atom to one tritium atom, but deuterium to deuterium is also feasible. Other fusion elements are simply way outside our technological capability and so are not reasonable candidates.

There are also many reactor designs. Basically you have to squeeze the elements close together at high temperature so as to have a sufficiently high probability of fusion. Stars use gravitational confinement to achieve this condition at their cores. We cannot do that on Earth, so we use one of two basic methods – inertial confinement and magnetic confinement. Inertial confinement includes a variety of methods that squeeze hydrogen atoms together using inertia, usually from implosions. These methods have achieved ignition (burning plasma) but are not really a sustainable method of producing energy. Using laser inertial confinement, for example, destroys the container in the process.

By far the best method, and the one favors by physics, is magnetic confinement. Here too there are many designs, but the one that is closest to the finish line (and the one used by CFS) is called a tokamak design. This is torus shaped in a specific way to control the flow of plasma just so to avoid any kind of turbulence that will prevent fusion.

In order to achieve the energies necessary to create sustained fusion you need really powerful magnetic fields, and the industry has essentially been building larger and larger tokamaks to achieve this. CFS has the advantage of being the first to design a reactor using the latest higher temperature superconductors (HTS), which really are a game changer for tokamaks. They allow for a smaller design with more powerful magnets using less energy. Without these HTS I don’t think there would even be a question of feasibility.

CFS is currently building a test facility called the SPARC reactor, which stands for the smallest possible ARC reactor, and ARC in turn stand for “affordable, robust, compact”. This is a test facility that will not be commercial. Meanwhile they are planning their first ARC reactor, which is grid commercial scale, in Virginia and which they claim will produce 400 Megawatts of power.

Reasons for optimism – the physics all seems to be good here. CFS was founded by engineers and scientists from MIT – essentially some of the best minds in fusion physics. They have mapped out the most viable path to commercial fusion, and the numbers all seem to add up.

Reasons for caution – they haven’t done it yet. This is not, at this point, so much a physics problem as an engineering problem. As they push to higher energies, and incorporate the mechanisms necessary to bleed off energy to heat water to run a turbine, they may run into problems they did not anticipate. They may hit a hurdle that will suddenly throw 10 or 20 years into the development process. Again, my take is that the 2035 timeline is if everything goes perfectly well. Any bumps in the road will keep adding years. This is a project at the very limits of our technology (as complex as going to the Moon), and delays are the rule, not the exception.

So – how close are they? The best so far is the JET tokamak reactor which produced 67% of net energy. That sounds close, but keep in mind, 100% is break even. Also – this is heat energy, not electricity. Modern fission reactors have about a 30% efficiency in converting heat to electricity, so that is a reasonable assumption. Also, this is fusion energy efficiency, not total energy. This is the energy that goes into the plasma, not the total energy to run the reactor.

The bottom line is that they probably need to increase their energy output by an order of magnitude or more in order to be commercially viable. Just producing a little bit of net energy is not enough. They need massive excess energy (meaning electricity) in order to justify the expense. So really we are no where near net total energy in any fusion design. CFS is hoping that their fancy new HTS magnets will get them there. They actually might – but until they do, it’s still just an informed hope.

I do hope that my pessimism, born of decades of overhyped premature tech promises, is overcalling it in this case. I hope these MIT plasma jocks can get it done, somewhere close to the promised timeline. The sooner the better, in terms of global warming. Let’s explore for a bit what this would mean.

Obviously the advantage of fusions reactors like the planned ARC design if it works is that it produces a lot of carbon-free energy. They can be plugged into existing connections to the grid, and produce stable predictable energy. They produce only low level nuclear waste. They also have a relatively small land footprint for energy produced. If the first ARC reactor works, we would need to build thousands around the world as fast as possible. If they are profitable, this will happen. But the industry can also be supported by targeted regulations. Such reactors could replace fossil fuel-based reactors, and then eventually fission reactors.

Once we develop viable fusion energy, it is very likely that this will become our primary energy source literally forever. At least for hundreds if not thousands or tens of thousands of years. It gets hard to predict technology that far out, but there are really no candidates for advanced energy sources that are better. Matter-antimatter theoretically could work, but why bother messing around with antimatter, which is hard to make and contain. The advantage is probably not enough to justify it. Other energy sources, like black holes, are theoretically and extremely exotic, perhaps something for millions of years advanced beyond where we are.

Even if some really advanced energy source becomes possible, fusion will likely remain in the sweet spot in terms of producing large amounts of energy cleanly and sustainable. Once we cross the line to being able to produce net total electricity with fusion, incremental advances in material science and the overall technology will just make fusion better. From that point forward all we really need to do is make fusion better. There will likely still be a role for distributed energy like solar, but fusion will replace all centralized large sources of power.

The post Plan To Build First Commercial Fusion Reactor first appeared on NeuroLogica Blog.