Rubin Observatory Data Flood Will Let the Universe Alert Astronomers 10 Million Times a Night
The Rubin Observatory released its first images last week, and they're stunning—vast, glittering star fields that show off the telescope's massive field of view and spectacularly deep vision. But two of the endeavor's most compelling aspects are difficult to convey in any individual image, no matter how spectacular: the sheer amount of data Rubin will produce and the speed with which those data will flood into astronomers' work.
'We can detect everything that changes, moves and appears,' says Yusra AlSayyad, an astronomer at Princeton University and Rubin's deputy associate director for data management. Any time something happens in Rubin's expansive view, the observatory will automatically alert scientists who may be interested in taking a closer look. The experience will be like receiving personalized notifications from the universe.
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That sounds straightforward enough—until you hear the numbers. 'We're expecting approximately 10,000 alerts per image and 10 million alerts per night,' AlSayyad continues. 'It's way too much for one person to manually sift through and filter and monitor themselves.' AlSayyad compares Rubin's data stream to a dashcam or a video doorbell that constantly films everything in its view. 'You can't just sit there and watch it,' she says. 'In order to make use of that video feed, you need data management.'
For Rubin, that means building a static image of the sky—a background template, so to speak—against which any changes will be easy to spot. The telescope will construct this static view within the first year or so of regular operations.
Once the background image for a particular section of the sky is ready, the real flood will begin. As the telescope snaps its gigantic photographs, algorithms will first automatically correct for effects such as stray light from the sky and image-blurring atmospheric turbulence. Then the algorithms will compare those tweaked images with the static template, marking every little difference—an expected 10,000 in each snapshot. There will be approximately 1,000 images per night, night after night, for as long as Rubin remains in operations.
Astronomers love data, but no one has that kind of time in a day. So each individual scientist (amateurs can sign up, too) must first enroll with the Rubin Observatory's so-called alert brokers. Users can request alerts about supernovae or asteroids, for example, then set constraints on just how interesting an event should be to trigger a notification.
Such limitations are important because, again, fielding 10 million alerts per night is an untenable prospect for anyone. 'It really is a kind of overwhelming scale of data,' says Eric Bellm, an astronomer at the University of Washington and Rubin's alert production science lead.
And that flood will continue for 10 years straight as the Rubin Observatory executes its signature project, dubbed the Legacy Survey of Space and Time (LSST). During this period, the telescope will zip its view across the sky in a carefully choreographed dance that will ultimately produce the best high-definition movie of the heavens that humanity has ever conceived.
Rubin's scientists have already sketched the basic survey, says Federica Bianco, an astronomer and data scientist at the University of Delaware and deputy project scientist at the Rubin Observatory. But many details will be worked out along the way, which will let them program the telescope to adapt to the astronomical community's interests, as well as any sudden celestial surprises.
'Ten years ago we were not really seriously thinking of gravitational-wave counterparts, which is all the rage today,' Bianco says. (These counterparts are the light-emitting sources of gravitational waves, the ripples in spacetime that scientists first measured in September 2015 using the twin Laser Interferometer Gravitational-Wave Observatory (LIGO) detectors.)
'We truly believe that LSST itself will discover new things, will transform the way in which we think about the universe,' she adds. That means making the observatory responsive to the cosmos. 'If that is true, then we need to enable changes that allow us to capture these new physics, these new phenomena.'
For some science, the discoveries will be limited by whatever the sky is gracious enough to give—a star must explode for the Rubin Observatory to spot a new supernova, for example. But a particularly intriguing case comes from planetary science within our own solar system. For centuries, astronomers have snagged observations of asteroids and comets—respectively, rocky and icy objects that swarm between and around the planets as all orbit the sun.
All that effort has put more than 1.3 million asteroids in our catalogs, but astronomers expect Rubin to identify perhaps three times that many new objects—practically without trying. When the LSST survey is running at full capacity, alerts for potential newfound asteroids will be sent straight to an international group called the Minor Planet Center, which tends a database of all such space rocks.
'We just sort of sit back and these objects will be discovered and reported to us,' says Meg Schwamb, an astronomer at Queen's University Belfast. Schwamb co-chairs the LSST Solar System Science Collaboration and has worked to estimate what the telescope will find in our cosmic neighborhood.
And because these space rocks are already out there, rattling through the solar system, Rubin will rack up discoveries quickly, Schwamb and her colleagues predict—with some 70 percent of new objects discovered during the survey's first two years.
'That, I think, is mind-blowing. That really allows us to start being able to watch these objects,' Schwamb says. 'There's instant gratification.'
Not everything Rubin will study is so speedy and unsubtle; the observatory will also be an astonishingly powerful tool for probing the enigmatic dark matter that produces no light yet holds galaxies together and outweighs the normal, familiar matter we know in our daily lives. One way astronomers study this lightless stuff is to measure how dark matter gravitationally warps light from more distant objects. Researchers use that telltale effect to map the enigmatic substance's distribution across the universe.
Decades ago Anthony Tyson, now an astrophysicist at the University of California Davis, wanted to do just that. 'I proposed a project to [what was then] the biggest telescope, the biggest camera that was in existence, and got turned down,' he recalls. In the long run, that failed proposal sent him down the path to build his own superlative telescope, which boasts the biggest digital camera in the world, at the Rubin Observatory, where he was founding director and is now chief scientist.
In the short run, however, he took an approach that now seems prophetic. 'I decided maybe I should make another application to take the same data but for a different purpose,' he says. He and his colleagues wrote up a different proposal for the same telescope, this time pitching a study of radio-bright plasma jets emanating from around the supermassive black holes at the core of galaxies. He got the observing time—as well as the warped light from invisible clumps of dark matter strewn along the telescope's line of sight. 'That was the scam,' he quips.
Now, decades later, the Rubin Observatory is opening astronomers' eyes to a new view of the universe. And while it won't observe radio light, it certainly will observe oodles of active galactic nuclei—by the tens of millions, in fact, repaying Tyson's slyly earned telescope time many times over.
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How NASA's Juno Probe Changed Everything We Know about Jupiter
The Juno spacecraft has rewritten the story on Jupiter, the solar system's undisputed heavyweight The NASA spacecraft tasked with uncovering the secrets of Jupiter, king of the planets, is running out of time. The Juno probe has already survived far longer than anticipated—its path around the solar system's largest planet has repeatedly flown it through a tempest of radiation that should have corroded away its instruments and electronics long ago. And yet here it is: one of the greatest planetary detectives ever built, still pirouetting around Jupiter, fully functional. But it may not be for long. September 2025 marks the end of Juno's extended mission. Although it could get another reprieve—an extended-extended mission—the spacecraft cannot carry on forever. Eventually the probe is fated to plunge into Jupiter's stormy skies, to lethal effect. Regardless of when that happens, the spacecraft's legacy is indelible. It revealed a whole different Jupiter than scientists thought they knew. Oddly geometric continent-size storms, in strange yet stable configurations, dance around its poles. Its heaviest matter seems to linger in its skies, while its abyssal heart is surprisingly light and fuzzy. Its innards don't resemble the lasagnalike layers found in rocky worlds; they look more like mingling swirls of different kinds of ink. [Sign up for Today in Science, a free daily newsletter] And Juno wasn't simply trying to understand Jupiter. It set out to uncover how the entire solar system was born. Jupiter, after all, was the first planet to piece itself together after the sun exploded into existence. Hidden underneath the planet's cloud tops, there is a recording of the beginnings of everything we see around us. 'That's the story behind why Juno was created: to go and look inside Jupiter every way we knew how, to try to figure out what happened in the early solar system that formed that planet—and what role that planet had in forming us,' says Scott Bolton, the mission's principal investigator at the Southwest Research Institute in San Antonio, Tex. Whenever a mission studies a planet or moon up close, 'you're going to be surprised' at what it finds, says Juno project scientist Steve Levin of NASA's Jet Propulsion Laboratory. But what you really want is 'to make the theorists throw everything out the window and start over.' Juno has torn up more textbooks than any other planetary science mission. 'It's been quite a ride,' Levin says. And scientists will never look at Jupiter, or the solar system, in the same way again. Jupiter, the Roman god, was often up to no good. According to myth, he obscured his mischief with a blanket of clouds so that nobody could see what he was up to. His wife, though, had the power to see through these clouds and monitor his shenanigans. Her name was Juno. In the late 1970s the two Voyager space probes gave humanity its first spectacularly detailed look at the gas giant. Unlike the deific Juno, they couldn't see Jupiter's buried secrets—but they were sufficiently inspiring for Bolton, who was a college student at the time. 'I had been a huge Star Trek fan and had fantasized about traveling around and wondering what the rest of the universe was like,' he says. When someone from JPL gave a talk at his school and showcased Voyager 1's jaw-dropping shots of Jupiter and its maelstroms, he was sold. 'I'd never seen anything like it.' In 1980 Bolton got a job at JPL, just as Voyager 1 was about to greet Saturn. Later he became part of the Galileo project, a mission to study Jupiter's atmosphere and magnetic field that orbited the planet from 1995 to 2003. It was the first spacecraft to orbit an outer planet and the first to drop a probe through its atmosphere. Although Galileo began to paint a picture of Jupiter in three dimensions, so much about the world—especially its core, the depth and nature of its storms, and its unseen polar regions—remained a mystery. Bolton ultimately came to an inescapable conclusion: science needed to make the mythical Juno real. As the new millennium dawned a spacecraft took shape, to the tune of $1.1 billion. A triumvirate of solar panels powered a suite of cloud-piercing instruments, some able to pick up on different types of radiation emanating from deep within the planet. One piece of tech can measure how the spacecraft is affected by small changes in the planet's gravitational field, allowing scientists to determine Jupiter's inner structure. Because every bit of added weight counts for a lot in spaceflight, the earliest Juno plans lacked a visual camera. It didn't need one to achieve its scientific objectives. But Candice Hansen-Koharcheck, a Juno team member and a senior scientist at the Planetary Science Institute in Tucson, Ariz., recalls Bolton saying: 'We can't fly to Jupiter without a camera.' The mission may be all about sensing what's below those clouds. But who doesn't want to catch a glimpse of alien hurricanes and vaporous whirlpools, too? JunoCam, led by Hansen-Koharcheck, was added to the payload. The biggest issue mission designers faced was figuring out how to shield the probe. The space environment enveloping Jupiter is thoroughly unpleasant. A torus of radiation, not only deadly to humans but also highly degrading to any electronics, zips around the planet's equator. Eventually this radiation will murder any spacecraft in its wake. To delay the inevitable, Juno deploys two radiation-dodging tricks. The first is to orbit in a way that repeatedly takes it over Jupiter's poles, where radiation is minimal. During each circuit, Juno gets as close as 3,100 miles to the planet's cloud tops, allowing it to conduct detailed scientific observations while spending a limited time bathed in aggressive radiation. The second is that its most vital electronics are encased inside a titanium vault. The spacecraft's hull is showered by more than 100 million dental x-rays' worth of radiation. Anything inside the vault receives about 800 times less. Juno's mission team hoped these strategies would keep the spacecraft alive for at least a year, but the scientists had only educated guesses to work with. 'No one's ever done a polar orbit. No one's ever slipped between the radiation belts,' says Heidi Becker, a researcher at JPL and the member of the Juno team responsible for monitoring the radiation environment. The only way to know was to go. 'I've been looking up at Jupiter for a very long time,' Becker says. She felt like the planet was teasing the Juno team before launch: 'Okay, bring it. Let's see if you can do it.' Juno left Earth in 2011 and reached Jupiter after a 1.7-billion-mile journey. It quickly took up a polar orbit of the elephantine world, and Becker and the team were overwhelmingly relieved when they realized that the radiation hadn't immediately exterminated the spacecraft. The scientists were also glad they'd packed that camera. The moment Juno opened its eyes, it witnessed a parade of colors rushing about with unrelenting force. The ever-changing landscapes weren't just painterly. 'They're like works of art,' says Bolton—impressionistic-looking spirals and streams, folding, arching and blooming in full view. Juno may be a scientific mission, but it also revealed Jupiter as a living van Gogh painting hanging in the sky. Within moments of falling into orbit, Juno revealed wonders—starting with the planet's freakish atmosphere and its gargantuan storms. When the probe peeked at Jupiter's poles, 'we saw something nobody's seen before,' Levin says. JunoCam and Juno's infrared mapping instrument, JIRAM, spied an octagonal collection of eight storms surrounding a central cyclone at the north pole. The south pole, meanwhile, had a pentagonal group of five storms circling another one in the middle. Each cluster of cyclones is larger than the U.S. The JIRAM image of the northern circumpolar cyclones resembled a 'beautiful, gigantic jack-o'-lantern in space,' Becker says. These geometric storms didn't just look striking—they had no precedent. 'The first time we saw the storms, I was with a bunch of people from the science team,' Levin says. 'Somebody literally said: 'Are you sure you got the right planet?' And they were only half joking.' The arrangement at each pole seemed oddly stable: storms moved around and jostled one another, but none disappeared. And to date, no one has a definitive explanation for why the number of storms at each pole differs, nor why their dance routine never seems to change. 'The way those cyclones are stable at the poles is still a mystery,' says Alessandro Mura, a researcher at the National Institute for Astrophysics in Rome and the lead for Juno's infrared mapping instrument. The most famous storm on Jupiter is its Great Red Spot—a rust-hued monster large enough to encompass the entire Earth. First seen a couple of centuries ago, it's known to change shape over time, and one day it may vanish. But until Juno arrived, astronomers' knowledge of it was surficial. By probing the radiation emitted by the spot's churning gases and by measuring its gravitational pull, the Juno team realized it reached a depth of about 300 miles below the cloud tops—almost 55 times deeper than Mount Everest is tall. Unsurprisingly, for a planet wreathed in storms, Jupiter experiences a lot of lightning; the Voyager missions caught bolts flashing through its clouds back in 1979. But Juno 'discovered a type of lightning that doesn't exist on Earth,' Becker says, which seemingly defied the laws of physics. Like many spacecraft, Juno has a star camera, an instrument that uses those diamantine dots to determine its orientation in space and aid its navigation. The camera can also spot lightning, which appears as bright specks. When Juno looked at the dark side of Jupiter, it spied tiny little flashes made by very high-altitude lightning bolts. That didn't make any sense. To produce lightning, liquid water needs to collide with ice crystals to create a spark. In 1979 the Voyager mission detected lightning coming from deep water clouds, where the suffocating pressure of the overlying atmosphere created temperatures high enough for liquid water to exist. But the lightning flashes picked up by Juno came from the upper echelons of Jupiter's atmosphere, a location so frigid that only ice crystals should exist there. After studying Jupiter's titanic clouds for a time, the Juno team worked out what was happening. The planet's cloud tops contain plenty of ammonia, and storms can launch ice into the sky that then binds to that ammonia. The chemical acts like antifreeze on the water-ice, causing it to turn into liquid droplets. And when those droplets smash into the upwardly propelled ice crystals, you get electricity—and vertiginous lightning. But this epiphany brought another mystery into focus. Sure, ammonia-ice clouds likely dominate Jupiter's skyline—but Juno found that some parts of the uppermost atmosphere have a dearth of ammonia. That didn't track: Jupiter's atmosphere looks incredibly turbulent—like a thoroughly whisked raw egg—so all its components should be mixed up, with a more or less even distribution of gases. How can many parts of the planet have 90-mile-deep wells lacking ammonia? 'There was no theory that could even remotely explain this,' says Chris Moeckel, a planetary scientist at the University of California, Berkeley. His first thought was that 'there's no way this is right.' But the data were sound. A complicated idea arose to make sense of the phenomenon. When the sky-high ammonia turns upwelling water-ice into liquid, the water and ammonia bond to form a peculiar slush with a water-ice shell. Ultimately softball-size globules of slush encased in ice fall back into the planet, where they melt at depths thought to be too extreme for Juno's instruments to detect. For a few years this theory seemed a bit too baroque to be true. But Moeckel and his colleagues became convinced thanks to the power of Juno's microwave radiometer. The instrument can measure radio waves that betray the presence of different chemical compounds. During one of its orbits, Juno noted a burst of ammonia production at an exceptional depth within the planet. According to Moeckel, this was a telltale sign that icy orbs had rained down from the sky and thawed, releasing their trapped water-ammonia slush. Researchers referred to this unique weather phenomenon as mushballs. 'It's such a stupid name,' Moeckel says. 'But it works.' Juno also trained its instruments on Jupiter's magnetic field, the largest structure in the solar system, which reaches at least as far as its neighboring planet, Saturn. But Juno discovered that Jupiter's magnetic field is wonky and asymmetric—more messy in the northern hemisphere than the south. There is also an intense concentration of magnetism near the equator, a patch (confusingly) called the Great Blue Spot. These characteristics are odd, but the existence of such a gargantuan field at all is the really strange part because Jupiter lacks the sloshing liquid iron and nickel responsible for Earth's magnetic field. Instead Jupiter contains an ocean of hydrogen, one under so much pressure that electrons are torn off individual hydrogen atoms, transforming it into an exotic, metal-like electrical fluid that generates its mighty magnetic field. Below the hydrogen sea lies an even bigger mystery—the question of what's inside the planet's innermost core. What Juno found there left scientists reeling. Before the spacecraft arrived, there were two prevailing notions about Jupiter's interior. The first was that the planet may have a compact core of rocky and metallic matter, not dissimilar to the cores of other worlds. If such a core exists, then Jupiter likely formed through the gradual clumping together of gas and solid matter, like the planets of the inner solar system. The second hypothesis was that there is no core at all. Instead Juno might find a ball of hypercompressed gas, suggesting Jupiter's formation was a bit like a failed star, one that didn't gather enough gas to trigger a thermonuclear ignition. 'Actually neither of those was true,' Bolton says. Juno used gravitational detective work to sense the core. The spacecraft is constantly communicating with Earth using radio waves. Jupiter's uneven mass means that Juno speeds up at times and slows down at others, depending on the strength of the gravitational pull it's experiencing. These speed changes cause subtle shifts in the wavelengths of the radio transmissions Juno sends and receives—effects that scientists can use to determine the internal structure of Jupiter. What they found was at first nonsensical. Deep within the metallic hydrogen ocean Juno detected an innermost core of, well, something; it's probably solid, but researchers can't tell. 'It's blending gradually into the surrounding layers,' says Ryan Park, a researcher at JPL and one of the leads on the gravity experiment on Juno. The hydrogen and the core material seem to mingle. The situation is very different from Earth's depths, where a lighter rocky mantle floats atop a denser iron and nickel core, between which is a distinct and definitive boundary. 'We frankly don't know how to explain that,' Levin says. And it gets weirder still. The sun and Jupiter are rich in both hydrogen and helium but are also expected to contain a smattering of heavier elements. Jupiter, a huge planet that most likely ate up rocky and icy planet-size shards during its formation, should contain far more heavy elements than the sun. And indeed, Juno found that Jupiter has three to four times as many heavy elements as our star. The problem, though, is that these elements appear to be found in the upper atmosphere—and the innermost core is comparatively lacking. All that heavy stuff should sink, via gravity, into the core. But apparently it hasn't. If the core is so light, then what could it possibly be made of? Scientists are scrambling for answers. This fuzzy core doesn't fit with anyone's model for planetary formation. Some scientists have suggested a giant meteor crashed into a once solid core, smashing it up and forcefully mixing it with the metallic hydrogen ocean. Levin wonders whether we simply don't understand the physics yet. 'We're talking about temperatures and pressures much higher than anything we're used to,' he says—conditions so severe that it's difficult to create them in laboratories. Other blockbuster findings from Juno concern Jupiter's moons. The probe's reconnaissance of two icy orbs—the pockmarked Ganymede and the ocean-concealing Europa (the target of a recently launched NASA habitability mission)—created breathtaking portraits of these dynamic worlds while also revealing some unusual chemistries. But a moon named Io got most of Juno's attention—and, consequently, generated the most shocking surprise. 'Io is a very peculiar moon because it's the most volcanic body of all,' Mura says. Its surface, an amalgam of burnt orange, sickly yellow and crimson hues, is covered in rocky cauldrons filled with lava, as well as volcanoes whose explosions propel magmatic matter into space. Up there the material is ionized by sunlight before plunging into Jupiter's skies, creating extremely bright auroral lights. Since the 1970s scientists have understood that Io's volcanism is powered by its elliptical orbit around Jupiter. When it's closer to Jupiter, it gets a bigger pull from the planet's gravity; when it's farther away, that pull is weaker. This back-and-forth kneads the moon like putty, creating tides in solid rock more than 300 feet high. All that motion creates a lot of friction, an abundance of heat—and a plethora of magma. Many thought that this mechanism, known as tidal heating, was so powerful that it created a continuous ocean of magma under the surface rather than the smaller, individual magma reservoirs that fuel Earth's volcanoes. The Galileo mission seemed to back that idea up: it detected an electrically conductive layer under Io's crust suggestive of a magma sea. But when Juno flew perilously close to Io on two occasions, getting within 900 miles of the violent surface, it found no trace of a shallow magma ocean. Mura now suspects Io's magma is partitioned into a maze of rocky tunnels, occasionally bubbling up into open rocky maws wherever the tunnels reach the surface. Nobody knows for sure; in typical Juno style, the observations have raised more questions than answers. But at least while scientists ponder possible solutions, they can marvel at Io's unbound ferocity. 'We discovered the largest eruption ever recorded,' Bolton says. In December 2024 Juno's infrared instrument detected a heat spike in the moon's southern hemisphere that briefly blinded the spacecraft's JIRAM instrument: a paroxysmal outpouring of lava spread over 40,000 square miles, enough to cover a quarter of California. It's producing more energy than the total annual energy output of humanity. 'And we still see it going on,' Bolton adds. By all accounts, Juno should be dead by now. The radiation should have already broken it or at least one of its instruments. Somehow it lasted well beyond its prime mission timeline, which ended in 2021. If an additional three-year extension is approved, Juno could get a better look at the planet's ghostly ring system, and some of its lesser-known innermost moons. But there's no telling how long the aging spacecraft could survive. 'It could grow old, and something could fail,' Bolton says. Perhaps 'the radiation will kill something so important that we can't function anymore.' Whenever the vehicle's end comes, it will go out in flames, spiraling toward the gas giant it spent its entire life interrogating. 'Eventually Juno will crash into Jupiter on its own,' Bolton says. But the spacecraft's legacy is already clear. Juno revealed Jupiter to be a far more confounding place than anyone dared imagine, forcing scientists to throw out reams of outdated ideas about planetary formation. It's also revealed how future spaceflight missions can defend themselves from the worst radiation in the solar system. The Juno team, having emulated its namesake's god-defying powers, is openly proud, Becker says. 'What an amazing success story for NASA.' Solve the daily Crossword
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The Universe Keeps Rewriting Cosmology
The universe has a habit of disproving 'unassailable' facts To astronomers in the 1990s, these three facts were self-evident: The universe is expanding; all the matter in the universe is gravitationally attracting all the other matter in the universe; therefore, the expansion of the universe is slowing. Two scientific collaborations assigned themselves the task of determining the rate of that deceleration. Find that rate, they figured, and they would know nothing less than the fate of the universe. Is the expansion slowing just enough that it will eventually come to a halt? Or is it slowing so much that it will eventually stop, reverse itself and result in a kind of big bang boomerang? The answer, which the two teams reached independently in 1998, was precisely the opposite of what they expected. [Sign up for Today in Science, a free daily newsletter] The expansion of the universe isn't slowing down. It's speeding up. Cosmology has often lent itself to unthinking assumptions that turned out to be exactly wrong. The ur-example is geocentrism. Over the couple of millennia before the invention of the telescope in the early 1600s, the occasional philosopher suggested Earth orbits the sun and not the other way around. But the vast majority of astronomers could simply look up and see for themselves. The sun orbits Earth. The evidence was, well, self-evident. But then, most of the history of astronomy had relied on an unthinking assumption: The heavens would always be out of reach. Like the prisoners in Plato's parable, we would forever be at the mercy of our perceptual limitations, trying to make sense of the motions in a two-dimensional celestial realm that was the cosmic equivalent of a cave wall. The invention of the telescope in the first decade of the 17th century overturned both those assumptions: Earth orbits the sun; the heavens are at our fingertips. More telescopic discoveries followed that, to varying extents, contradicted one self-evident 'fact' after another: mountains on the moon, moons around Jupiter, new stars, new planets. Some assumptions turned out to have been not just unthinking but unthinkable. How could anyone in the history of civilization ever have looked at Saturn and thought, 'I'm assuming it doesn't have rings'? That the universe is expanding—the major premise leading to the 1990s search for the deceleration rate—was a revelation that nobody saw coming, including the two theorists who made the discovery not only conceivable but inevitable. The first, Isaac Newton, would have had to make two counterintuitive leaps of logic to reach such a shocking conclusion. He would have needed to imagine that the universe was capable of doing what it self-evidently was not doing: collapsing. Then he would have needed to conceive of it as doing the opposite: getting bigger. Albert Einstein, the second theorist who paved the way for the expansion discovery, did conceive of it. In November 1915 he presented the equations underlying his general theory of relativity; 15 months later he applied those equations to, as he phrased the topic in the paper's title, 'cosmological considerations.' According to his math, the universe should be volatile over time, either expanding or contracting. To avoid that unsettling implication, he introduced a variable, L, the Greek symbol for lambda, to balance his equation. The value of lambda would be whatever it needed to be to satisfy Einstein's preference for a universe in perfect balance. Each theorist's 'blunder,' as Einstein characterized his own refusal to trust his math, was understandable. Newton and Einstein, however intellectually exceptional, were still only human. The universe was static. If evidence to the contrary existed, it certainly wasn't obvious. And then it was. In the early 1920s American astronomer Edwin Hubble deployed the new 100-inch telescope atop Mount Wilson in California to observe some of the nebulous smudges at the farthest reaches of previous telescopes. Using Cepheid variables (stars that brighten and dim with clockwork regularity) as a measure of distance, he inferred that at least some of those nebulae were actually 'island universes'—galaxies—beyond our own Milky Way. Next he used the redshifts of those galaxies to infer not only that the galaxies are moving away from us and from one another—itself a science-redefining discovery—but also their rate. When Hubble plotted those distances against those velocities on an x/y graph, he found a direct correlation: the more distant the galaxies, the faster they were moving away from us. Thus, the universe must be expanding. Belgian astronomer Georges Lemaître independently reached the same conclusion, working not from his own data but from Einstein's equations. Trace the expansion backward, he argued, and you would arrive at a 'primeval atom.' Evidence supporting the existence of such a 'big bang' didn't come until 1964, in the form of a background of microwave radiation that seems to pervade all of space. Theorists had predicted the existence of such a background as the relic of an explosive origin, although the two Bell Labs astronomers who first detected the radiation initially dismissed it as noise, possibly the result of pigeon droppings lining the giant horn of their radio antenna. Four physicists at nearby Princeton University, however, recognized that the observation matched the key prediction of the big bang theory. Six years later American astronomer Allan Sandage cast cosmology as 'the search for two numbers.' One number was the 'rate of expansion' now. The other, however, harbored the unthinking assumption that would motivate two teams of researchers a quarter of a century later: 'the deceleration in the expansion' over time. Both teams trying to measure cosmic deceleration followed Hubble's methodology of plotting velocity versus distance on a graph (using the magnitudes of a type of exploding star, or supernova, rather than Cepheid variables). Both collaborations expected to find the same direct correlation that Hubble did—at least at first. At some distance, though, they assumed that the line would depart from its 45-degree trajectory and dip, indicating that the apparent magnitudes of the supernovae were brighter, and therefore nearer, than they would be in a universe expanding at a constant rate. And depart from its 45-degree trajectory the line did. Only it didn't dip. It rose. The supernovae were dimmer, and thus farther away, than they would be in a universe expanding at a constant rate. The expansion of the universe, the rival teams concluded, isn't slowing down. It's somehow speeding up. Dark energy—as cosmologists came to call whatever was causing the acceleration—soon became part of the standard cosmological model, along with dark matter and 'regular' matter, the stuff of us. Observations of the same cosmic microwave background that, back in the 1960s, helped to validate the big bang interpretation of cosmology have revealed the universe's ingredients. By studying the patterns in the radiation, scientists have refined the contributions to the mass-energy density of the universe to an exquisite level of precision: 4.9 percent of it must be ordinary matter, 26.8 percent dark matter, 68.3 percent dark energy. The model, cosmologists believe, is solid. But not flawless. Not even complete. What is dark energy? What is dark matter? Indeed, even after all these years: What is the fate of the universe? Just this year the Dark Energy Spectroscopic Instrument in Arizona provided evidence that dark energy may have changed over the course of the evolution of the universe. Cosmologists have found the evidence compelling, though its meaning—let alone its implications for the standard model of cosmology—remains elusive. So: Is cosmology on the precipice of another reversal? Another revolution? If history is any guide, the answer is: Maybe. For all today's cosmologists know, they might be laboring under a seemingly unassailable, self-evident, yet incorrect assumption. Perhaps even an unthinking one. It's happened before. Solve the daily Crossword
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Age of happiness? Oh to be blissfully young or older and wiser
There is disagreement among researchers regarding the age and stage of life when people are most happy. It is a complicated issue with many factors – but a number of studies have come to the same basic conclusion: Older adults are happier than younger adults. The following is from a Psychology Today publication titled 'Happiness Over the Lifespan:' 'The happiness curve refers to the trajectory that happiness tends to follow as we age. People begin life fairly happy. Around age 18, their happiness begins to decrease, reaching a low point in their 40s. But after age 50, happiness begins to rise again. This U-shaped happiness curve has emerged consistently in large studies of Western societies.' An excerpt from a Princeton University report on research completed (along with two other universities) on the topic is as follows: 'When looking at life satisfaction scores across regions, the researchers confirmed a well-known 'U-shaped curve' that bottoms out between the ages of 45 and 54 in high-income, English speaking countries. These countries include the United States, Canada, the United Kingdom, Ireland, Australia and New Zealand. This curve indicates that, in these countries, middle-age residents report the lowest levels of life satisfaction, which eventually bounces back up after age 54.' The increase in happiness with age was again reflected in a study at the School of Social Ecology at University of California, Irvine. UCI researchers followed 1,000 people age 22 to 95, over two decades. Participants were asked about their emotional well-being (positive and negative emotions they were feeling) that day, in the past week and in the past month. The study, which was titled 'Growing Old and Being Old: Emotional Well-Being Across Adulthood,' and published in the Journal of Personality and Social Psychology, concluded that older people were, in general, happier (more positive) and less negative than younger adults. Susan Charles, UCI professor of psychological science and nursing science, was quoted as follows: 'We found that when looking at all responses across all participants, older adults reported the highest level of well-being compared to all other age groups. They reported the lowest levels of distress (great sadness and anxiety) as well as the lowest level of reported negative emotions (feeling lonely, afraid and upset). They also reported the highest levels of positive emotions (being calm, enthusiastic and cheerful) than younger adults.' The findings should come as no big surprise. Not many of us zoom through high school and college, find the perfect life partner, get the perfect job, then live happily ever after with perfect children. The middle years are often fraught with disappointments – bad relationships, unmet expectations, financial difficulties. In contrast, it sometimes doesn't take much to produce happiness in the very young – although studying this population would seem to be a challenge. A survey consisting of questions, for instance, might not work with toddlers since many are not yet able to talk. To 'happy-assess' a toddler, the parents or grandparents would most likely need to be surveyed. 'Right now, (2-year-old) Benjamin (Azahares Vazquez) seems happiest when he is throwing things,' said his grandmother, Anabel Perez, laughing. 'Maybe one day he'll throw a baseball 100 miles an hour, make a fortune in the major leagues, and share the money with his family.' There is no definitive age of peak happiness. But if the experts are correct, living beyond the 50s age range may provide the answer. Benjamin's baseball career would be over by then. Mark Ryan is a Tallahassee RN. This article originally appeared on Tallahassee Democrat: Happiest years? Researchers find young adults struggle Solve the daily Crossword
