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Tag Archives: physics
Trio win Nobel physics prize for tiny light pulses that give snapshot of atoms – Reuters
- Trio win Nobel physics prize for tiny light pulses that give snapshot of atoms Reuters
- Nobel in medicine goes to 2 Penn scientists whose work enabled creation of mRNA vaccines 6abc Philadelphia
- Scientists Katalin Karikó and Drew Weissman win Nobel for mRNA vaccine: How their cutting edge technology helped us tame COVID-19 The Indian Express
- With Nobel Prize in medicine, a new laurel for ‘eds and meds’ in Philadelphia | Editorial The Philadelphia Inquirer
- Karikó and Weissman’s Nobel for mRNA Shows Power of Perseverance Bloomberg
Euclid Space Telescope To Shed Light on the Dark Universe – “A Revolution in Physics Is Almost Guaranteed” – SciTechDaily
- Euclid Space Telescope To Shed Light on the Dark Universe – “A Revolution in Physics Is Almost Guaranteed” SciTechDaily
- Euclid telescope, sent to illuminate the universe’s biggest mysteries, shares first test photos CNN
- We Just Got The First Test Images From Europe’s Dark Matter Telescope And We’re Psyched ScienceAlert
- ESA on Euclid’s first space image success..Tech & Science Daily Podcast Evening Standard
- Dark Universe Explorer: Euclid’s Large Halo Orbit Around Infinitesimal Point SciTechDaily
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Why More Physicists Are Starting to Think Space and Time Are ‘Illusions’
This past December, the physics Nobel Prize was awarded for the experimental confirmation of a quantum phenomenon known for more than 80 years: entanglement. As envisioned by Albert Einstein and his collaborators in 1935, quantum objects can be mysteriously correlated even if they are separated by large distances. But as weird as the phenomenon appears, why is such an old idea still worth the most prestigious prize in physics?
Coincidentally, just a few weeks before the new Nobel laureates were honored in Stockholm, a different team of distinguished scientists from Harvard, MIT, Caltech, Fermilab and Google reported that they had run a process on Google’s quantum computer that could be interpreted as a wormhole. Wormholes are tunnels through the universe that can work like a shortcut through space and time and are loved by science fiction fans, and although the tunnel realized in this recent experiment exists only in a 2-dimensional toy universe, it could constitute a breakthrough for future research at the forefront of physics.
But why is entanglement related to space and time? And how can it be important for future physics breakthroughs? Properly understood, entanglement implies that the universe is “monistic”, as philosophers call it, that on the most fundamental level, everything in the universe is part of a single, unified whole. It is a defining property of quantum mechanics that its underlying reality is described in terms of waves, and a monistic universe would require a universal function. Already decades ago, researchers such as Hugh Everett and Dieter Zeh showed how our daily-life reality can emerge out of such a universal quantum-mechanical description. But only now are researchers such as Leonard Susskind or Sean Carroll developing ideas on how this hidden quantum reality might explain not only matter but also the fabric of space and time.
Entanglement is much more than just another weird quantum phenomenon. It is the acting principle behind both why quantum mechanics merges the world into one and why we experience this fundamental unity as many separate objects. At the same time, entanglement is the reason why we seem to live in a classical reality. It is—quite literally—the glue and creator of worlds. Entanglement applies to objects comprising two or more components and describes what happens when the quantum principle that “everything that can happen actually happens” is applied to such composed objects. Accordingly, an entangled state is the superposition of all possible combinations that the components of a composed object can be in to produce the same overall result. It is again the wavy nature of the quantum domain that can help to illustrate how entanglement actually works.
Picture a perfectly calm, glassy sea on a windless day. Now ask yourself, how can such a plane be produced by overlaying two individual wave patterns? One possibility is that superimposing two completely flat surfaces results again in a completely level outcome. But another possibility that might produce a flat surface is if two identical wave patterns shifted by half an oscillation cycle were to be superimposed on one another, so that the wave crests of one pattern annihilate the wave troughs of the other one and vice versa. If we just observed the glassy ocean, regarding it as the result of two swells combined, there would be no way for us to find out about the patterns of the individual swells. What sounds perfectly ordinary when we talk about waves has the most bizarre consequences when applied to competing realities. If your neighbor told you she had two cats, one live cat and a dead one, this would imply that either the first cat or the second one is dead and that the remaining cat, respectively, is alive—it would be a strange and morbid way of describing one’s pets, and you may not know which one of them is the lucky one, but you would get the neighbor’s drift. Not so in the quantum world. In quantum mechanics, the very same statement implies that the two cats are merged in a superposition of cases, including the first cat being alive and the second one dead and the first cat being dead while the second one lives, but also possibilities where both cats are half alive and half dead, or the first cat is one-third alive, while the second feline adds the missing two-thirds of life. In a quantum pair of cats, the fates and conditions of the individual animals get dissolved entirely in the state of the whole. Likewise, in a quantum universe, there are no individual objects. All that exists is merged into a single “One.”
“I’m almost certain that space and time are illusions. These are primitive notions that will be replaced by something more sophisticated.”
— Nathan Seiberg, Princeton University
Quantum entanglement reveals to us a vast and entirely new territory to explore. It defines a new foundation of science and turns our quest for a theory of everything upside down—to build on quantum cosmology rather than on particle physics or string theory. But how realistic is it for physicists to pursue such an approach? Surprisingly, it is not just realistic—they are actually doing it already. Researchers at the forefront of quantum gravity have started to rethink space-time as a consequence of entanglement. An increasing number of scientists have come to ground their research in the nonseparability of the universe. Hopes are high that by following this approach they may finally come to grasp what space and time, deep down at the foundation, really are.
Whether space is stitched together by entanglement, physics is described by abstract objects beyond space and time or the space of possibilities represented by Everett’s universal wave function, or everything in the universe is traced back to a single quantum object—all these ideas share a distinct monistic flavor. At present it is hard to judge which of these ideas will inform the future of physics and which will eventually disappear. What’s interesting is that while originally ideas were often developed in the context of string theory, they seem to have outgrown string theory, and strings play no role anymore in the most recent research. A common thread now seems to be that space and time are not considered fundamental anymore. Contemporary physics doesn’t start with space and time to continue with things placed in this preexisting background. Instead, space and time themselves are considered products of a more fundamental projector reality. Nathan Seiberg, a leading string theorist at the Institute for Advanced Study at Princeton, is not alone in his sentiment when he states, “I’m almost certain that space and time are illusions. These are primitive notions that will be replaced by something more sophisticated.” Moreover, in most scenarios proposing emergent space-times, entanglement plays the fundamental role. As philosopher of science Rasmus Jaksland points out, this eventually implies that there are no individual objects in the universe anymore; that everything is connected with everything else: “Adopting entanglement as the world making relation comes at the price of giving up separability. But those who are ready to take this step should perhaps look to entanglement for the fundamental relation with which to constitute this world (and perhaps all the other possible ones).” Thus, when space and time disappear, a unified One emerges.
Courtesy Hachette Book Group
Conversely, from the perspective of quantum monism, such mind-boggling consequences of quantum gravity are not far off. Already in Einstein’s theory of general relativity, space is no static stage anymore; rather it is sourced by matter’s masses and energy. Much like the German philosopher Gottfried W. Leibniz’s view, it describes the relative order of things. If now, according to quantum monism, there is only one thing left, there is nothing left to arrange or order and eventually no longer a need for the concept of space on this most fundamental level of description. It is “the One,” a single quantum universe that gives rise to space, time, and matter.
“GR=QM,” Leonard Susskind claimed boldly in an open letter to researchers in quantum information science: general relativity is nothing but quantum mechanics—a hundred-year-old theory that has been applied extremely successfully to all sorts of things but never really entirely understood. As Sean Carroll has pointed out, “Maybe it was a mistake to quantize gravity, and space-time was lurking in quantum mechanics all along.” For the future, “rather than quantizing gravity, maybe we should try to gravitize quantum mechanics. Or, more accurately but less evocatively, ‘find gravity inside quantum mechanics,’” Carroll suggests on his blog. Indeed, it seems that if quantum mechanics had been taken seriously from the beginning, if it had been understood as a theory that isn’t happening in space and time but within a more fundamental projector reality, many of the dead ends in the exploration of quantum gravity could have been avoided. If we had approved the monistic implications of quantum mechanics—the heritage of a three-thousand-year-old philosophy that was embraced in antiquity, persecuted in the Middle Ages, revived in the Renaissance, and tampered with in Romanticism—as early as Everett and Zeh had pointed them out rather than sticking to the influential quantum pioneer Niels Bohr’s pragmatic interpretation that reduced quantum mechanics to a tool, we would be further on the way to demystifying the foundations of reality.
Adapted from The One: How an Ancient Idea Holds the Future of Physics by Heinrich Päs. Copyright © 2023. Available from Basic Books, an imprint of Hachette Book Group, Inc.
This Physicist Says Electrons Spin in Quantum Physics After All. Here’s Why : ScienceAlert
‘Spin’ is a fundamental quality of fundamental particles like the electron, invoking images of a tiny sphere revolving rapidly on its axis like a planet in a shrunken solar system.
Only it isn’t. It can’t. For one thing, electrons aren’t spheres of matter but points described by the mathematics of probability.
But California Institute of Technology philosopher of physics Charles T. Sebens argues such a particle-based approach to one of the most accurate theories in physics might be misleading us.
By framing the groundwork of matter primarily in terms of fields, he says, certain peculiarities and paradoxes that emerge from a particle-centric view melt away.
“Philosophers tend to be attracted to problems that have been unsolved for a really long time,” says Sebens.
“In quantum mechanics, we have ways of predicting the results of experiments that work very well for electrons and account for a spin, but important foundational questions remain unanswered: Why do these methods work, and what’s happening inside an atom?”
For the better part of a century, physicists have wrestled with the results of experiments that suggest the smallest pieces of reality don’t look or behave anything like objects in our everyday lives.
Spin is one of these qualities. Like a whirling cue ball colliding with the inner wall of a billiard table, it carries angular momentum and influences the direction of a moving particle. Yet, unlike the cue ball, a particle’s spin can never speed up or slow down – rather, it’s always confined to a set value.
To make the basic nature of matter even harder to picture, consider the fact an electron’s size is so small that it effectively lacks volume. If it were large enough to have volume, the negative charge spread throughout that space would push on itself, tearing the electron apart.
Significantly, even if we were to be charitable and grant the electron as a particle the largest radius experiments would allow for, its rotation would overtake the speed of light – something which might or might not be a deal-breaker on this scale, but for many physicists is enough to dismiss talk of rotating electrons.
One way to make the tapestry of fundamental physics a little easier to map is to describe points of matter as actions embedded into the weave of a field and then interpret these actions as particles.
Quantum field theory (QFT) does this successfully, weaving together aspects of Einstein’s special theory of relativity, classical field theory, and the particle propositions of quantum physics.
It’s not a controversial theory, yet there is still debate over whether those fields are fundamental – existing even if the blips that ripple through them were to fall silent – or if particles are the main actors that represent the vital information and fields are just a convenient script.
To us, it might seem like a trivial distinction. But to philosophers like Sebens, the consequences are worth exploring.
As he explained in a 2019 article featured in Aeon magazine: “Sometimes progress in physics requires first backing up to reexamine, reinterpret, and revise the theories that we already have.”
That reexamination of quantum field theory emphasizes several significant advantages to making fields a priority in physics over a particle-first approach, including a model that re-imagines electrons in ways that might give us better insights into their behavior.
“In an atom, the electron is often depicted as a cloud showing where the electron might be found, but I think that the electron is actually physically spread out over that cloud,” Sebens says.
By being physically spread out through a field rather than confined to a point, an electron might actually rotate in ways that are less mathematical constructs and more a physical description.
Although it would still not be anything like a tiny planet in a solar system, this rotating electron would at least move at a speed that doesn’t challenge any laws.
Just how this diffuse spread of negatively charged matter resists blowing itself apart is a question Sebens doesn’t have an answer for. But by focusing on the field aspects of a spread-out electron, he feels any solutions would make more sense than issues that arise from particles of infinite confinement.
There’s a quote that has become folklore in the halls of quantum theorists – “Shut up and calculate.” It’s become a saying synonymous with the aphantasic landscape of the quantum realm, where imagery and metaphor fail to compete with the uncanny precision of pure mathematics.
Every now and then, though, it’s important to pause our calculations and indulge in challenging a few old assumptions – and maybe even turn around for a new perspective on the fundamentals of physics.
This paper was published in Synthese.
Why This Universe? Maybe It’s Not Special—Just Probable
Cosmologists have spent decades striving to understand why our universe is so stunningly vanilla. Not only is it smooth and flat as far as we can see, but it’s also expanding at an ever-so-slowly increasing pace, when naive calculations suggest that—coming out of the Big Bang—space should have become crumpled up by gravity and blasted apart by repulsive dark energy.
To explain the cosmos’s flatness, physicists have added a dramatic opening chapter to cosmic history: They propose that space rapidly inflated like a balloon at the start of the Big Bang, ironing out any curvature. And to explain the gentle growth of space following that initial spell of inflation, some have argued that our universe is just one among many less hospitable universes in a giant multiverse.
But now two physicists have turned the conventional thinking about our vanilla universe on its head. Following a line of research started by Stephen Hawking and Gary Gibbons in 1977, the duo has published a new calculation suggesting that the plainness of the cosmos is expected, rather than rare. Our universe is the way it is, according to Neil Turok of the University of Edinburgh and Latham Boyle of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, for the same reason that air spreads evenly throughout a room: Weirder options are conceivable but exceedingly improbable.
The universe “may seem extremely fine-tuned, extremely unlikely, but [they’re] saying, ‘Wait a minute, it’s the favored one,’” said Thomas Hertog, a cosmologist at the Catholic University of Leuven in Belgium.
“It’s a novel contribution that uses different methods compared to what most people have been doing,” said Steffen Gielen, a cosmologist at the University of Sheffield in the United Kingdom.
The provocative conclusion rests on a mathematical trick involving switching to a clock that ticks with imaginary numbers. Using the imaginary clock, as Hawking did in the ’70s, Turok and Boyle could calculate a quantity, known as entropy, that appears to correspond to our universe. But the imaginary time trick is a roundabout way of calculating entropy, and without a more rigorous method, the meaning of the quantity remains hotly debated. While physicists puzzle over the correct interpretation of the entropy calculation, many view it as a new guidepost on the road to the fundamental, quantum nature of space and time.
“Somehow,” Gielen said, “it’s giving us a window into perhaps seeing the microstructure of space-time.”
Imaginary Paths
Turok and Boyle, frequent collaborators, are renowned for devising creative and unorthodox ideas about cosmology. Last year, to study how likely our universe may be, they turned to a technique developed in the ’40s by the physicist Richard Feynman.
Aiming to capture the probabilistic behavior of particles, Feynman imagined that a particle explores all possible routes linking start to finish: a straight line, a curve, a loop, ad infinitum. He devised a way to give each path a number related to its likelihood and add all the numbers up. This “path integral” technique became a powerful framework for predicting how any quantum system would most likely behave.
As soon as Feynman started publicizing the path integral, physicists spotted a curious connection with thermodynamics, the venerable science of temperature and energy. It was this bridge between quantum theory and thermodynamics that enabled Turok and Boyle’s calculation.
The South African physicist and cosmologist Neil Turok is a professor at the University of Edinburgh.Photograph: Gabriela Secara/Perimeter Institute
The physics behind building an enduring soap bubble
Blowing soap bubbles, besides being a favorite pastime for children, also happens to be an art form and a subject of interest for physicists. Emmanuelle Rio, François Boulogne, Marina Pasquet, and Frédéric Restagno from the Laboratory of Solid State Physics at the University of Paris-Saclay have been studying bubbles for years, trying to understand the different processes at play in these innocuous-looking structures.
“Bubbles are important as they appear in many places, including washing products, cosmetics, building materials, and also in nature. For example, sea foam plays a role in terms of the exchanges between the atmosphere and the sea,” Boulogne said.
Now, the team has described a key event in the life of bubbles: when they pop.
Taking the temperature
In a recent study, Boulogne and Rio established the role played by the temperature of the bubbles’ surface in their stability. “In some cases, the aging of the bubbles and their bursting has been associated with the thickness of the soap film. Recently, researchers began associating the thinness of the soap film with evaporation. However, in our study, we pointed out that heat transfer, which is associated with evaporation, wasn’t taken into account,” Boulogne said.
To explore this aspect, the researchers measured the temperature of the bubbles’ surface and found a significant difference compared to room temperature. “The temperature of bubbles’ surface can decrease by up to 8° Celsius,” Boulogne said.
Boulogne stated that although there is a link between temperature and aging of the bubbles, the impact of low temperatures on when the bubbles pop remains to be understood—and is likely to stay that way for a while. “So far, we have no model that can make this prediction. Understanding the stability of bubbles is a challenge that will take several decades,” he said.
He reasoned there are several factors that need to be considered when it comes to the stability of bubbles. “This includes temperature, rate of evaporation, film-thinning, marginal regeneration (the phenomenon of small patches, which are thinner and lighter than the surrounding film, rising toward the top), and geometry. To have all these factors in a single model is very challenging.”
Building the perfect bubble
While predicting the stability of bubbles in different scenarios may take some time, Rio identified an optimal combination of ingredients to make bubbles last longer while at the same time being easy to create.
The key to longevity is glycerol. The other ingredients include a long polymer like the naturally occurring guar gum and “optimum proportion” of dishwashing liquid. “If you add more dishwashing liquid, creating bubbles becomes easier. However, their life time is shortened. That’s why you need to find the right amount of dishwashing liquid to ensure bubbles last long enough and are easy to generate,” Rio said.
Working with the French artist Pierre-Yves Fusier, who specializes in bubbles art, Rio and her colleagues developed the recipe, which consists of 40 milliliters of dishwashing liquid, 100 milliliters of glycerol, and 1 gram of long polymer such as the naturally occurring guar gum mixed in 1 liter of water. Using this recipe, Rio created 5 cm-diameter bubbles in her laboratory that lasted an hour.
While adding glycerol may make the bubbles more stable, Rio said the impact of other ingredients on the bubbles’ stability is still an open question. “Glycerol is a hydroscopic molecule which can help condensate water. But we know the surfactant (dishwashing liquid) and the polymer also impact evaporation. The next step in our study, therefore, is to find out how our recipe impacts the evaporation,” Rio said.
Rio added that evaporation, which is yet to be completely understood, is just one phenomenon that plays a role in bubble bursting. “You also have to consider gravity, which contributes to thinning of the surface that leads to the fluctuation of film thickness. All of this makes it extremely difficult to predict when a bubble will burst,” Rio said.
Dhananjay Khadilkar is a journalist based in Paris.
Scientists steer lightning bolts with lasers for the first time | Physics
Scientists have steered lightning bolts with lasers for the first time in the field, according to a demonstration performed during heavy storms at the top of a Swiss mountain.
The feat, which involved firing powerful laser pulses at thunderclouds over several months last year, paves the way for laser-based lightning protection systems at airports, launchpads and tall buildings.
“Metal rods are used almost everywhere to protect from lightning, but the area they can protect is limited to a few metres or tens of metres,” said Aurélien Houard, a physicist at École Polytechnique in Palaiseau. “The hope is to extend that protection to a few hundred metres if we have enough energy in the laser.”
Lightning bolts are huge electrical discharges that typically spark over two to three miles. The charge carried in a bolt is so intense that it reaches 30,000C, about five times hotter than the surface of the sun. More than a billion bolts strike Earth each year, causing thousands of deaths, 10 times as many injuries, and damage that runs into tens of billions of dollars.
Traditional lightning rods date back to Benjamin Franklin who used to chase thunderstorms on horseback before his famous kite experiment in 1752. But in more recent times, scientists have looked for other ways to protect buildings and objects from damaging strikes.
Writing in the journal Nature Photonics, Houard and colleagues in Switzerland describe how they carted a powerful laser to the top of the Säntis mountain in north-eastern Switzerland and parked it near a 124m-high telecoms tower that is struck by lightning about 100 times a year.
The scientists waited for storms to gather and between July and September last year, fired rapid laser pulses at thunderclouds for a total of more than six hours. Instruments set up to record lightning strikes showed that the laser diverted the course of four upward lightning discharge over the course of the experiments.
Only one strike, on 21 July, happened in clear enough conditions for the researchers to film the path of the lightning from two directions using high speed cameras several kilometres away. The footage shows that the lightning bolt followed the laser path for about 50 metres, suggesting that the pulses helped steer the strike.
The laser diverts lightning bolts by creating an easier path for the electrical discharge to flow down. When laser pulses are fired into the sky, a change in the refractive index of the air makes them shrink and become so intense that they ionise air molecules around them. This leads to a long chain of what the researchers call filaments in the sky, where air molecules rapidly heat up and race away at supersonic speeds, leaving a channel of low density, ionised air. These channels, which last for milliseconds, are more electrically conductive than the surrounding air, and so form an easier path for the lightning to follow.
The laser is powerful enough to be a risk to the eyes of overflying pilots, and during the experiments air traffic was closed over the test site. But the scientists believe the technology could still be useful, as launchpads and airports often have designated areas where no-fly restrictions apply. “It’s important to consider this aspect of safety,” said Houard.
More powerful lasers that operate at different wavelengths could guide lightning over longer distances, he added, and even trigger lightning before it becomes a threat. “You avoid it going somewhere else where you cannot control it,” Houard said.
“The cost of the laser system is very high compared with that of a simple rod,” said Professor Manu Haddad, director of the Morgan-Botti Lightning Laboratory at Cardiff University. “However, lasers could be a more reliable way to direct the lightning discharge, and this may be important for the lightning protection of critical ground installations and equipment.”
Physicist Says the Laws of Physics Don’t Actually Exist
“Like peeling an infinite onion, the more we peel, the more there is to peel.”
Galaxy Brain
The majority of physicists live under the assumption of a strict and immutable set of laws that govern the universe — but not all.
“What we often call laws of physics are really just consistent mathematical theories that seem to match some parts of nature,” theoretical physicist Sankar Das Sarma writes in the beginning of a must-read new column in New Scientist column. These laws of physics are meant to describe our shared reality, even if they “evolve as our empirical knowledge of the universe improves.”
“Here’s the thing,” Sarma continues. “Despite many scientists viewing their role as uncovering these ultimate laws, I just don’t believe they exist.”
Prior to Albert Einstein’s groundbreaking — and ultimately unfinished — attempts to create a theory of everything, and all the leaps in fields like quantum mechanics that followed, the physicist argues, such an assertion wouldn’t have seemed outlandish.
Indeed, Sarma says he finds it “amazing” that humans “can make sense of some aspects of the universe through the laws of physics” at all.
“As we discover more about nature, we can hone our descriptions of it, but it is never-ending,” he writes. “Like peeling an infinite onion, the more we peel, the more there is to peel.”
Multiverse Madness
Pointing to the concept of the multiverse, or an infinite number of universes, Sarma ponders how humans could have such hubris as to imagine that the apparent rules that seem to govern our reality would apply in every universe.
Raising a theoretical argument, Sarma adds that even in the face of a theory as substantial as quantum mechanics, which he describes as being “more like a set of rules that we use to express our laws rather than being an ultimate law itself,” there remain too many mysteries and variables to ever consider this so-called fundamental theory sacrosanct.
“It is difficult to imagine that a thousand years from now physicists will still use quantum mechanics as the fundamental description of nature,” he continues. “Something else should replace quantum mechanics by that time just as quantum mechanics itself replaced Newtonian mechanics.”
What that replacement may be, Sarma declines to speculate. But he nevertheless sees “no particular reason that our description of how the physical universe seems to work should reach the pinnacle suddenly in the beginning of the 21st century and become stuck forever at quantum mechanics.”
“That would,” he adds, “be a truly depressing thought!”
More on physics: Those Headlines About Scientists Building a Wormhole Are Total Nonsense, People
Scientists Propose Mind-Bending Plan to Look for Dark Matter, New Physics Near the Sun
The Sun. Image: NASA via Getty Images
ABSTRACT breaks down mind-bending scientific research, future tech, new discoveries, and major breakthroughs.
Physicists have proposed a mind-boggling space mission that might finally expose the true nature of dark matter, an enigmatic substance that is considered one of the biggest unsolved mysteries in science, reports a new study.
Dark matter is about five times more plentiful in the universe than the familiar stuff that makes up stars, planets, and even our bodies, distinguishing it as a fundamental component of the universe. But despite its abundance, dark matter has proved completely inscrutable to our instruments, and it has never been directly detected; we only know that it exists due to indirect observations of its gravitational influence over luminous bodies, such as galaxy clusters.
Scientists have developed many sophisticated techniques to snag the first direct detection of dark matter, a milestone that could answer a whole host of open questions about our universe, but all have come up short so far.
Now, a team led by Yu-Dai Tsai, a physicist at the University of California, Irvine, has proposed a fascinating space mission that would use the most accurate clocks ever invented to search for dark matter that might be bound to the Sun. In this way, the concept mission, which the team calls SpaceQ, could potentially uncover “new physics” and “study many fundamental physics topics,” according to a study published in Nature Astronomy on Monday.
“Dark matter is one of the most important remaining mysteries in astronomy and cosmology, given its unknown and elusive nature,” Tsai said in an email to Motherboard. “If we could find dark matter and understand its properties, we can understand the evolution of our universe, and understand many astrophysical measurements better, including the velocity distribution of these objects in the small scale (from small galaxies to galaxy clusters).”
“This will also be one of the most significant breakthroughs in particle physics as it is one of the final remaining ingredients to our understanding of particle physics as well,” he added.
The SpaceQ mission concept is built around the incredible accuracy of what the team calls “quantum clocks,” a category that includes existing atomic clocks, which are ultra-precise instruments that use oscillations within atoms to tell time, as well as molecular and nuclear clocks that are currently in development, and are expected to be even more sensitive. In addition to telling time, these clocks can measure incredibly subtle changes in atomic frequencies.
To that end, Tsai started thinking about the possibility of using these clocks to search for a hypothetical version of dark matter, known as ultralight dark matter (ULDM), which theories suggest could become bound to the Sun in a structure called a dark matter halo. A space mission to the Sun might be able to detect ULDM particles, assuming they exist, by measuring tiny changes in the frequencies of the atomic transitions in quantum clocks that expose ULDM’s interactions with other forms of matter.
“We show that the projected sensitivity of space-based clocks for detection of a Sun-bound [dark matter] halo exceeds the reach of Earth-based clocks by orders of magnitude,” Tsai and his colleagues said in the study.
“At present, to our knowledge, this is the only proposal capable of reaching these target sensitivities in our parameter space of interest,” they added.
Since 2020, Tsai has been developing the concept with study co-authors Marianna Safronova, an expert in atomic physics at the University of Delaware, and Joshua Eby, a dark matter expert at the Kavli Institute for the Physics and Mathematics of the Universe.
“The solar probe mission would allow the atomic clocks to study enhanced dark matter density close to the Sun, and probe very interesting and motivated target models detailed in our paper,” Tsai noted. “In addition, we can also test the variation of the fundamental constants, with the change of gravitational potential, when we go close to the Sun. This has been one of the main fundamental physics motivations for developing precise clocks.”
The trio were inspired, in part, by two pioneering NASA missions: the Deep Space Atomic Clock, a test of an unprecedented space navigation clock launched in 2019, and the Parker Solar Probe, which was launched in 2018 and has since traveled closer to the Sun than any other mission. SpaceQ is a dazzling mashup of these two trailblazing missions that combines the Sun-grazing maneuvers of Parker with the sensitive atomic measurements of the deep space clock.
“The Deep Space Atomic Clock (DSAC) is a technology for us to realize space travel, and the Parker Solar Probe is an amazing mission for us to study the Sun,” Tsai said. “Both are existing and cutting-edge technologies with practical purposes. It is amazing to utilize them to study fundamental physics, not to mention the combination of them.”
At this point, the mission is still just an idea, but it offers a novel approach to search for dark matter that could potentially be much more effective than existing techniques. Plus, on a pure gut level, how wild would it be to search for dark matter—one of the biggest missing links in the universe—around our Sun using a daredevil probe carrying ludicrously precise clocks?
“A network of clocks in space and on Earth can study many fundamental physics topics, including transient topological dark matter and multimessenger signatures of exotic particles,” the researchers concluded in the study. “In our consideration, if a signal were to be present, the comparison of ground- and space-based clocks could help to map the density of [dark matter] in the vicinity of Earth to further constrain the bound [dark matter] scenario.”