65792875
submission
StartsWithABang writes:
Every once in a while, a river develops a sandbar island in the middle. Normally, this happens because it carves a small tributary through one of its banks, creating an isolated island. Unfortunately, over time, the rushing water erodes the island in the middle, something that happens very quickly if there isn't a large, complex root system to fight the erosion processes. For those of you who feel that once person can't make a difference, meet the ultimate counterexample: the man who planted an entire forest, saved an island, and defended herds of wildlife from would-be poachers.
65772737
submission
StartsWithABang writes:
It's a phenomenon we've all experienced: you've got a roaring fire going and you're excited to keep it burning for longer, so you throw an extra two or three large logs on it. A half hour later, all you've got left are coals. It might not make intuitive sense, but you would have been better off just putting a single log on — in other words, adding less fuel — if you wanted your fire to last longer. Here's the science of why.
65727029
submission
StartsWithABang writes:
Handing your health and fitness over to a reality show, where the goal is to lose as much of your weight as possible in the shortest amount of time, might not be the healthiest long-term option, but for a chance at a quarter of a million dollars, it's worth it for some. Imagine how frustrated you'd be, though, if you learned that you should have been the winner, but weren't, all because of the rounding errors inherent to the format of the show. They not only often send the wrong person home, but may have crowned the wrong winner as a result of this common math mistake!
65701011
submission
StartsWithABang writes:
It’s such a part of our cosmic and scientific history, that it’s difficult to remember that it’s only been for the past 50 years that the Big Bang has been the leading theory-and-model that describes our Universe. Ever since the 1920s, when Edwin Hubble discovered the apparent expansion of our Universe, we’ve recognized that it’s a much bigger place than simply what’s in the Milky Way. But the Big Bang was hardly the only game in town. Yet the discovery of not only the Cosmic Microwave Background, but the detailed measurement of its temperature and spectrum, was able to rule out every single alternative as a non-viable model.
65657447
submission
StartsWithABang writes:
The Universe exists as it does; we exist in the Universe; therefore, the Universe needed to have such properties that at least allowed for the possibility of us arising. Is that a trivially true statement? Is that simply a useless tautology? Or can something like this actually be informative, and guide us in a useful direction when it comes to our understanding of the Universe? Theoretical physicist Sabine Hossenfelder explores these and other issues, including the multiverse, in this fascinating look into the anthropic principle.
65630215
submission
StartsWithABang writes:
The formation of new stars happens in stages: cold molecular gas clouds contract and collapse under their own gravity, forming proto-stars in the densest regions that grow to undergo nuclear fusion. The new stars then emit ionizing radiation, and burn off the rest of the nebula, leaving a young star cluster behind. For the most part, we observe this story in different stages when we look at different objects, but there's one place in our galaxy where the entire story is being told all at once. It's the Eagle Nebula: the one place in our galaxy that showcases all the stages of star formation simultaneously!
65608443
submission
StartsWithABang writes:
We like to think of the Mercury 7 — the very first group of NASA astronauts — as the "best of the best," having been chosen from a pool of over 500 of the top military test pilots after three rounds of intense physical and mental tests. Yet when women were allowed to take the same tests, one of them clearly distinguished herself, outperforming practically all of the men. If NASA had really believed in merit, Jerrie Cobb would have been the first female in space, even before Valentina Tereshkova, more than 50 years ago. She still deserves to go.
65559395
submission
StartsWithABang writes:
The past century saw a revolution in the way we perceive the nature of the Universe. Rather than being made up of fixed space and time, general relativity brought along with it spacetime, and the idea that it wasn't fixed at all but rather dynamical. We discovered that the fabric of this spacetime itself is expanding over time, and by measuring multiple independent lines of evidence, we determined that the expansion itself is accelerating. This general phenomenon is due to dark energy, but what exactly is this dark energy we speak of so frequently? The observations are good enough now that we can (preliminarily) say that it's a cosmological constant, or the energy inherent to space itself, or the non-zero zero-point-energy of the quantum vacuum. There's still a little wiggle room, but not much!
65531065
submission
StartsWithABang writes:
If you can reach the fabled "breakeven point" of nuclear fusion, you’ll have opened up an entire new source of clean, reliable, safe, renewable and abundant energy. You will change the world. At present, fusion is one of those things we can make happen through a variety of methods, but — unless you’re the Sun — we don’t have a way to ignite and sustain that reaction without needing to input more energy than we can extract in a usable fashion from the fusion that occurs. One alternative approach to the norm is, rather than try and up the energy released in a sustained, hot fusion reaction, to instead lower the energy inputted, and try to make fusion happen under “cold” conditions. If you listen in the right (wrong?) places, you'll hear periodic reports that cold fusion is happening, even though those reports have always crumbled under scrutiny. Here's why, most likely, they always will.
65491903
submission
StartsWithABang writes:
Last week, outlets reported an independent test of the E-cat, an alleged cold fusion device that could revolutionize energy for our world. Or, alternatively, it could simply be a hoax perpetrated by a charlatan and a team of either accomplices or incompetents. How would you distinguish between the two? When you look at the scientific standards, the results of the "independent test" leave a lot to be desired.
65419715
submission
StartsWithABang writes:
4.6 billion years ago, a large molecular cloud collapsed in the Milky Way, giving rise to around a thousand or so new stars and star systems, one of which just happened to become our home. But those early days showcased a violent time for our Solar System, and wasn't so different from what's currently taking place in the Omega Nebula, just 5,500 light years away in our own galaxy. Take an in-depth look inside, and catch a glimpse of what our Solar System's environment was like back during its earliest days!
65363645
submission
StartsWithABang writes:
Nothing in this Universe lasts forever: not life, planets, stars, atoms or even galaxies. But the longest-lived thing of all — black holes — have a limit on their lifetime, too! The phenomenon of Hawking radiation ensures that even they will decay and evaporate after a long enough time. But the popular picture — of particle-antiparticle pairs created outside the event horizon, with one falling in and the other escaping — is wildly oversimplified, and creates the misconception that Hawking radiation is particles-and-antiparticles escaping. It isn't; it's a blackbody spectrum of photons, and here's what you need to know about what actually goes on!
65308729
submission
StartsWithABang writes:
If you want to take the best-ever images of objects in deep space, you build the largest possible telescope, you equip it with the best possible camera equipment, and you send it up to space. Right? Only, the "large" part and the "send it to space" part are mutually exclusive! We can build much larger telescopes on the ground than we can send to space, so how, then, could ground-based observatories ever compete with something like Hubble? You need to find a way to adapt to the ever-changing, turbulent atmosphere. Believe it or not, that's exactly what the lasers these observatories shoot allow us to do!
65305201
submission
StartsWithABang writes:
If you want an electron to be free, all you have to do is put in enough energy to ionize an atom. If you want a mass to be free, all you need is enough energy to overcome its gravitational binding. But a quark is a tricky thing: as much as we might try, we can never free it from being bound to other quarks (or antiquarks). The reason is tricky, and its explanation won the Nobel Prize exactly 10 years ago. Here's a great explainer o the physics behind it.
65247377
submission
StartsWithABang writes:
Yes, the 2014 Nobel Prize in Physics went to the invention of the blue LED, which came about through a new technique in diode creation that has been used, copied and improved upon over the past 20 years. Many people have been outraged that such a mundane discovery won the Nobel Prize, but the physics behind it is undeniably groundbreaking, not to mention the applications.
