65201803
submission
StartsWithABang writes:
Globular clusters are some of the oldest objects in the Universe, with typical ages ranging from 10 billion years to more than 13 billion years, approaching the age of the Universe itself. Intermediate mass black holes have been found in a few of them: small versions of the supermassive black holes found at the center of most galaxies. In 2012, astronomers identified two stellar mass black holes near (but not at) the center of Messier 22, the brightest globular cluster visible from Earth, and it's now believed that there are around 100 black holes in every single globular in the sky!
65184479
submission
StartsWithABang writes:
If you’ve ever participated in BOINC projects such as Einstein@home, SETI@home, Malaria Control or one of many protein folding projects, you recognize the power of using the idle cycles of your CPU (and GPU) for helping science. But that’s nothing compared to what the Charity Engine is doing to help science, charities and build the world’s largest cloud-based supercomputer for lease only by vetted, ethical companies! For those of you with tons of old hardware lying around, you've got no excuse not to do it.
65143481
submission
StartsWithABang writes:
When you look at a black hole from the outside, there are only a few quantities of it that you can measure: its mass, electric charge and angular momentum. Whether it was made of matter, antimatter or dark matter is lost to its history. But based on what we know of astrophysics and the Universe, we can calculate how much dark matter ought to be eaten by them over the Universe's history. As it turns out, black holes are born dark-matter-free, but can grow to have up to 0.004% of their mass originate from dark matter. Normal matter: not doing so bad for just 5% of the Universe!
65120993
submission
StartsWithABang writes:
The Universe as we know it (i.e., when it's filled with "stuff" like matter and radiation) has been expanding and cooling for 13.8 billion years, leading up to the present day. Does that mean we can see for 13.8 billion light years in all directions? Under the laws of General Relativity, it turns out that would be impossible, as the Universe must be either expanding or contracting. So how big is it? 46 billion light years in radius, with only a very small uncertainty!
65113805
submission
StartsWithABang writes:
One of the biggest questions in all of science is that of just how ubiquitous — or rare — life in the Universe is. With the sole exception of Earth, all the worlds in our Solar System seem devoid of life. Or at least, their detection has eluded us so far. But what of all the other planets, star systems and galaxies in the Universe? We all share the same common, cosmic history, and as far as we can tell, the ingredients for life are everywhere. But for the first time in human history, we may not need life to come and contact us; we can simply stay here and look for surefire signatures from afar. Come find out how we may be on the cusp of, for the first time, finding out we’re not alone in the Universe!
65073937
submission
StartsWithABang writes:
I wasn’t all that long ago — just 50 years — that we didn’t know where our Universe came from. A hot, dense early state? A cyclical, swirling past? Or perhaps a time-independent one, where the Universe back then was not so different from our own today? All that changed in 1964, quite by accident. With the first detection of the Cosmic Microwave Background, and its identification as the leftover glow from the Big Bang, we entered a new era of cosmology, one that wasn’t primarily based in speculative, theoretical calculations, but one that could distinguish between possible Universes from careful, progressively improved measurements of our Universe. Today, we’re on the precipice of taking the next step, and finding out what gravitational waves may have imprinted themselves from the earliest moments of our observable Universe. Come learn the status of where we are now, and how we're going to take the next step!
65064187
submission
StartsWithABang writes:
When it comes to physics, there sure are some strange theories — and even stranger phenomena — out there. The notion that particles don’t have fixed, intrinsic properties that are simultaneously measurable can only be described as weird, and the fact that you can add as much energy as you want to a particle but it will never accelerate to beyond a particular speed is certainly counterintuitive. Yet one theory has them all beat. For ninety-nine years, now, General Relativity has made a whole host of unique predictions, ranging from time slowing down in a gravitational field to the bending of starlight to the decay of pulsar orbits, that have been observationally confirmed each and every time. It's the strangest theory we know to be true, and we're on the brink of testing (and possibly confirming) its predictions to even better precision!
64909781
submission
StartsWithABang writes:
The next great leap in human spaceflight is a manned mission to a world within our Solar System: most likely Mars. But if something went wrong along the journey — at launch, close to Earth, or en route — whether biological or mechanical, would there be any way to return to Earth? A fun (and sobering) look at what the limits of physics and technology allow at present.
64874851
submission
StartsWithABang writes:
The greatest story ever told is the one the Universe tells us about itself: how it went from a state of empty and expanding spacetime to one containing the huge number of galaxies, stars, planets and atoms, not to mention you. Here is the shortest version of that story ever that is still accurate and comprehensive, with ten sentences covering the entire thing!
64873101
submission
StartsWithABang writes:
For all the aspiring supervillains out there, you may have heard that Stephen Hawking recently wrote about the possibility of the Higgs field destroying the Universe. As it turns out, that's not very likely to happen, not likely to affect us if it does happen, and not something we can control in any case. But there is something we can do if we were intent on destroying the Universe: restore the inflationary state that gave rise to the Universe (and the Big Bang) in the first place!
64793609
submission
StartsWithABang writes:
When you think of astrology today, you likely think of someone who makes false promises and proclaims either platitudes or fabrications as though they were preordained truths. That's not even an unfair judgment. For many millennia dating to just a few centuries ago, though, astrology was anything but. Our initial thoughts on the idea that what happens in the heavens affects what happens on Earth may have been flawed, but as it turns out, the simple idea of observing the Universe beyond our own world has been able to teach us more than the ancients would have ever dreamed! A fascinating look at the story of where science itself originated.
64782643
submission
StartsWithABang writes:
When you think of Einstein — beyond the quotable old guy with the crazy hair — you probably think of trains moving near the speed of light, matter converting into energy (and vice versa), the fabric of space and time or perhaps the equivalence principle. Yet all of these ideas, special and general relativity, E=mc^2 and so on, sprung from the same source, the gedankenexperiment, or thought-experiment. It's amazing what the human mind, all on its own, can accomplish, including knocking on the door of the newest frontiers in science!
64645939
submission
StartsWithABang 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!
64614359
submission
StartsWithABang 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!
64580403
submission
StartsWithABang 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.
