StartsWithABang (3485481) writes "When we look out into the Universe, we can see fainter and farther than ever before simply by building larger telescopes and having them take longer exposures: in other words, by gathering more light. But even in principle, there's a limit to what we can see, thanks to the fact that, beyond a certain point, the Universe was an ionized plasma, randomizing whatever information was contained in the light passing through it. But that doesn't mean we can't see beyond that point, it just means we can't use light to do it! Gravitational waves are the future of astronomy, and can even tell us how the Universe got its start!"
StartsWithABang (3485481) writes "The Big Bang has, among its predictions, three cornerstones: the Hubble Expansion of the Universe, the Cosmic Microwave Background, and the abundance of the Light Elements due to Big Bang Nucleosynthesis. The first one has been confirmed to spectacular accuracy, and with the COBE, WMAP and Planck satellites, the spectrum and fluctuations in the CMB rule out almost every other feasible alternative. But detecting the abundance of the light elements directly has always run into a difficulty: the formation of stars in the Universe pollutes the intergalactic medium, ruining our ability to see anything "pristine." We'd have to get incredibly lucky, to find a region of molecular gas that had never formed stars in-between our line-of-sight to a quasar or bright galaxy. For nearly 70 years, that didn't happen, and then all of a sudden, we found two. The Big Bang stands tall after all!"
StartsWithABang (3485481) writes "Sure, the idea of destroying an entire planet may sound like an unachievable dream of a pathological teenager, as the energy required would be tremendous. To simply overcome the gravitational potential energy binding an Earth-sized planet together would require the entire energy output of the Sun added up over more than a week! But if we could harness a relatively small amount of antimatter — just 0.00000000002% the mass of the planet in question — that would be enough to do it."
StartsWithABang (3485481) writes "During sunset, the Sun appears to redden, dim, and eventually sink below the horizon. Every once in a while, a rare phenomenon emerges along with it: a green flash, where a greenish-colored beam of light appears just over the Sun. What causes it? One of the most beautiful natural phenomena our planet has to offer, explained in glorious detail."
StartsWithABang (3485481) writes "You may have just heard that we’ve mapped out our supercluster of galaxies — Laniakea — to unprecedented accuracy, identifying a region 500 million light-years in diameter that’s responsible for our local group’s motion through space. While it's an amazing feat of astronomical mapping and cluster identification, calling a structure like this a “supercluster” implies that, in some way, the galaxies, galactic groups and galaxy clusters that make this up are in some way bound together. But this is in no way the case! Come find out why “superclusters” aren’t so super after all."
StartsWithABang (3485481) writes "In 1992, scientists discovered the first planets orbiting a star other than our Sun. The pulsar PSR B1257+12 was discovered to have its own planetary system, and since then, exoplanet discoveries have exploded! But before that, in 1963, decades of research led to the much-anticipated publication and announcement of the first exoplanet discovered: around Barnard's star, the second-closest star system to Earth. Unfortunately, it turned out to be spurious, and that in itself took years to uncover, an amazing story which is only now fully coming to light!"
StartsWithABang (3485481) writes "Tonight marks the third-and-final Supermoon of the year, but the physics governing the Moon will be no less super or spectacular all year long. Next month, a total lunar eclipse awaits us, while lunar libration allows us to see up to 59% of the Moon's surface over the course of the month, not a mere 50% like you might expect. What's the physics (and astronomy) governing the Moon? Summer Ash has the entire, comprehensive story."
StartsWithABang (3485481) writes "Hydroelectric dams are one of the best and oldest sources of green, renewable energy, but — as the Three Gorges Dam in China exemplifies — they often cause a host of environmental and ecological problems and challenges. One of the more interesting ones is how to coax fish upstream in the face of these herculean walls that can often span more than 500 feet in height. While fish ladders might be a solution for some of the smaller dams, they're limited in application and success. Could Whooshh Innovations' Salmon Cannon, a pneumatic tube capable of launching fish up-and-over these dams, finally restore the Columbia River salmon to their original habitats?"
StartsWithABang (3485481) writes "Now that dark energy is firmly in place as the dominant source of energy in the Universe, the race is on to figure out exactly what its properties are, and what that will mean for the Universe's fate. If it's truly a cosmological constant, we're in for a Big Freeze, as galaxies expand away from one another faster and faster, leaving only our gravitationally-bound local group behind. But if dark energy changes over time, we might yet see a Big Crunch or the most horrifying of all fates: a Big Rip, where galaxy-by-galaxy, star-by-star and eventually atom-by-atom, everything is torn apart!"
StartsWithABang (3485481) writes "When you think of the most recognizable collections of stars: the Big Dipper, Cassiopeia, the “Teapot” in Sagittarius and the Southern Cross, they might have prominent stars, but none of them crack the top 10 in terms of brightness. Who, then, are the brightest stars in the sky? Come see how many you know, and find what makes them shine so brightly, and why they're not representative of most stars in the Universe!"
StartsWithABang (3485481) writes "Convinced that the risks of nuclear power are too great for the world? That air travel is unsafe? That GMOs are poisoning our world and our bodies? That fluoridated drinking water causes long-term harm? That climate change isn't a manmade thing? Or that vaccines cause more harm than good? Unless you're willing to drop your ideology and completely cast it aside, you'll never accept what science says about these issues, and therefore you're preventing us all from making a better world. Cut it out!"
StartsWithABang (3485481) writes "When you think about the stars in the sky, it takes some study to realize that the bluest, brightest stars are also the shortest lived. So when we look at a cluster of stars — or any stellar population — we can figure out how old it is by looking at the color and magnitude of the brightest, bluest main-sequence stars that are still alive. In general, the oldest objects are the reddest globular clusters, which formed when the Universe was only a few hundred million years old. Because the Universe was mostly hydrogen and helium at the time, enriched by relatively few generations of stars, these clusters tend to have very small amounts of heavy elements like iron, sometimes as little as 1% of what’s in our Sun. So when a star cluster has a color/magnitude diagram that says it's very old but a heavy element abundance that says it's relatively young, who wins? We all do, by learning more about how, when and where atomic riches accumulate in galaxies!"
StartsWithABang (3485481) writes "Although dark energy has always been present in the Universe, it didn't come to dominate the Universe's energy content until recently. But even before that, its effects on the Universe's expansion rate could be felt, and it caused distant galaxies to begin accelerating away from us. Thanks to the precision measurements that have come out since the Planck satellite, we're now able — for the first time — to pinpoint with tremendous accuracy exactly when the Universe transitioned from a decelerating to an accelerating state. Come have your misconceptions about dark energy and cosmic acceleration cleared up here. (And no, the expansion rate itself isn't increasing; it's still going down!)"
StartsWithABang (3485481) writes "Labor Day is this coming Monday, and that means the new school year is about to start. Whether you are or whether you know a young person, say in middle-or-high school, you’re likely very close to someone facing a lot of uncertainty about not only their future, but about their present. Who can be expected to know exactly what they want to do and exactly how to get the most out of it when they’re only a teenager? Yet that’s what we expect most students to do. For students that are interested in STEM — science, technology, education and mathematics — the pressure is even greater. So what advice should you give them? Here’s a great start, from someone who’s been there and who’s helped a generation of kids go through it!"
StartsWithABang (3485481) writes "When you look out into the Universe at distant galaxies, at clusters of galaxies or at the Universe on the largest scales, what you see is the luminous stuff, which is pretty exclusively stars and stellar-related objects. But based on what we know about gravitation on those scales, we know there’s got to be much more mass than that, most of which doesn’t emit light: dark matter. It seems like a great leap to presume that there’s a new type of matter out there accounting for these observations. Could normal, non-luminous matter possibly account for all the dark matter? No, and here’s why it can't!"