david attenborough is wonderful. i cherish 'life in the undergrowth' the most but i honestly love everything he does.
@BPD anon asked me about rare weather phenomena, and mentioned ice fog in particular, so here are a few of my favorite winter occurrences: ice fog Ice fog is a type of fog consisting of fine ice crystals suspended in the air. It occurs only in cold areas of the world, as water droplets suspended in the air can remain liquid down to −40 °C (−40 °F). It should be distinguished from diamond dust, a precipitation of sparse ice crystals falling from a clear sky.[1] It should also be distinguished from freezing fog, which is commonly called pogonip in the western United States. we get this maybe once or twice each winter here in minnesota; it's a lot more common in alaska and northern canada, but sometimes in january and february a plume of arctic air comes blasting down the center of the continent from the north pole all the way to the great plains, and then this crazy shit abounds. when the air is full of suspended ice crystals at -40 degrees, you stay the fuck indoors. D: sun dogs seen these many times, almost every day at the coldest part of the winter. ice crystals high in the atmosphere refract little segments of rainbow around the sun. they're patches rather than a full rainbow because the crystals are flat and tend to drift horizontally, like frisbees. snow rollers look at this goofy ass shit just look at it what the fuck nature these are pretty rare; you need sticky snow on top of powder, and a high wind. ice tsunami i'll take "things that make me glad i didn't buy lakeshore property" for 500, alex. no, nobody died. it wasn't a huge wave smashing down. it was just a slow, inexorable piling-up of lake ice by the wind, until it just... smooshed everything. the video's 6 minutes, you can p much skip most of it and still get the full effect, it's just interesting to listen to the lady go from "what is this, it's so funny, maybe i should move the table tho" to "IT'S GOING RIGHT THROUGH THAT FUCKING HOUSE" over the course of six minutes. and the ice kept piling up for hours after that. watermelon snow fun! it's an algae. don't eat it, it'll give you the shits. and finally, my absolute favorite winter phenomenon: THUNDER SNOW snowstorms usually don't have the kind of convection you need to get lightning. but sometimes... just sometimes... when thor is skiing or something... you get this amazing purplewhite world of snow and electricity, and it makes me feel alive. aLIVE I TELL YOU!!! MWAHAHAHAHA!!!!!
here's another interesting winter phenomenon: the superior mirage otherwise known as the optic trick that sank the titanic. @Vast Derp i know you're going to be interested in this if you haven't already heard about it: http://www.dailymail.co.uk/sciencet...-finds-freak-weather-hidden-iceberg-late.html it's not named for lake superior, but for the direction of the optic flip i guess. we've seen this effect on lake superior a bunch of times, though. we see ore tankers flying through the air and laugh about it like "hey there goes the S.S. Clipping Error!" -- but in the days before radio and radar, it could be deadly.
I don't think I've ever seen the two-spots sundogs, but I have seen full 22 halos around both the sun and the moon. See those arcs extending up and down from the bright spots in @jacktrash's pic up there? If the sun's at a slightly different angle with respect to the floating flat ice crystals, those join up to form an even halo all the way around the sun (the ring appears 22 degrees of arc away from the sun, hence the name. you can also get a second halo at 46 degrees of arc, but those are a lot rarer and I've never seen one). You can actually get both a full halo and brighter sundogs to the sides of the sun at once, although I've only seen pictures. There are a whole bunch of other rare arcs of light and whatnot produced by sunlight refracting through suspended ice crystals that can link up with 22 halos and sundogs. Like so: Also if there's not a magic gun called a .22 Halo in some story somewhere, there needs to be, stat. The other awesome atmospheric bullshit that I've had the privilege of seeing is something called a circumhorizontal arc, or fire rainbow. A full circumhorizontal arc runs parallel to the horizon, 46 degrees of arc below the sun (and thus lying tangent to a 46 halo, if there is one), but mostly you just see fragments of it in cirrus clouds along that line when the conditions are right. The above picture really doesn't do it justice, the colors are vivid, a lot more so than in iridescent clouds I believe, and they shift slowly as the sun moves. The one I saw was the only cloud in the sky, out in the Channeled Scablands of Eastern Washington that Jesse mentioned upthread, and it was shaped almost exatly like a feather, even with little non-rainbow downy wisps at the bottom. It remains a strong contender for the most beautiful thing I have ever seen.
i dunno, that was just the most concise print article i've seen about it. i first heard about the finding from smithsonian and national geographic.
i used to live in northern ontario, so we got quite a few weird weather occurrences (i've seen ice fog & sun dogs, also once i got to see thunder snow & it blew my 8 yr old mind), but i think the best one i've seen is a funnel cloud: tiny cloud dick one of these knocked out power to the city for 3 days, right before i moved (can i just say that all these weather phenomena are really really pretty? because they are. the thunder snow deserves to be on a heavy metal album cover. maybe more than one. so does the rainbow cloud)
Pluto reminds me of the moon a bit, only smoother. What a good planet. (Shush, pluto is always gonna be a planet to me) Hello science nerds, I haz question: WTF even is ball lightening, and how does it happen?
short answer: nobody knooooooows! slightly less short answer: there are a lot of theories, and it's really hard to test them, so the field hasn't been narrowed down much. the wiki page is actually a pretty decent starting point: https://en.wikipedia.org/wiki/Ball_lightning it seems to like to travel along power lines, as seen here:
KINTSUGIJIN, LET'S TALK ABOUT PLUTO! (Or rather, I'm going to talk about Pluto. I will neither confirm nor deny rumors that I may have teared up at my desk at work watching the press conferences because I fucking love science, okay?) In case you've been living under a rock this week, the New Horizons spacecraft made its closest approach to Pluto on Tuesday the 14th. New Horizons was launched on January 19th, 2006. After a gravitational slingshot from Jupiter in 2007, the spacecraft went into hibernation for the long coast to the outer solar system. It was brought back online in December 2014 and began the approach to Pluto in January. New Horizons carries a bunch of instruments, intended to make high-resolution elevation maps, study the composition of the surface and the atmosphere, measure the solar wind and the dust particle density in Pluto's vicinity, and of course, take some really stunning pictures. It whipped past Pluto at 30,800 mph (49,600 km/h) and most of the data collection is now complete, but because the bandwidth it has available for streaming data back to Earth is extremely limited (1 kbit/s or less), we will be receiving the data in little bits and pieces over the next few months. But what we've already got is amazing. Pluto, showing the "heart" feature, now called the Tombaugh Region after the discoverer of Pluto. Mountains near Pluto's equator. The mountains are as much as 11,000 feet high and are made (probably) of water ice. Nitrogen ice covers most of Pluto's surface, with some carbon monoxide and methane ice found in places. Pluto also has a thin mostly-nitrogen atmosphere, formed as nitrogen ice sublimates into a gas. Pluto's moon Charon, showing large canyons and a prominent (and mysterious) dark spot. Here's the mission website with lots and lots of shiny stuff. And an article in Wired with some explanations.
@WithAnH, you forgot to mention the weirdest thing! >:C Those ice mountains there? Judging my the number of craters on them (not many), they are probably not older than 100 million years. That's younger than the Appalachians. That's only a little older than the Rockies. Meaning Pluto is geologically active in some way.
@Wiwaxia I didn't forget! Don't make glare faces at me! I'm doing my research to make sure I don't completely screw up my geophysics before I post about why it's so surprising to find geological activity on Pluto and Charon. :)
WHO WANTS TO SEE AN 18TH CENTURY SEX TOY FOUND IN AN ANCIENT LATRINE IN POLAND??? ARCHAEOLOGY, EVERYBODY (Im so sorry)
Pluto post, part 2! To explain why scientists are so surprised to find young mountains on Pluto, we have to take a brief detour into geophysics. (Note that I am not a geophysicist - anyone more knowledgeable about the subject matter should feel free to correct me if I make mistakes!) All of the geological processes on Earth, from volcanism to plate tectonics, are driven by Earth's internal heat. This heat comes from two sources: primordial heat, which is the leftover energy from the collisions that formed Earth, and radiogenic heat, which is heating due to the decay of radioactive isotopes. Both of these sources of heat are decreasing with time, so Earth now is much less geologically active than it was 4 billion years ago. So what happens on a body much smaller than the Earth? Say, the Moon? The Moon is a little more than 1% of the mass of the Earth. It has a core, mantle, and crust like the Earth, but unlike the Earth, it has no plate tectonics and no active volcanoes. From approximately 4 billion years ago all the way up to 1 billion years ago, there was volcanic activity on the Moon - the maria (the dark areas that you can see with the naked eye) are made of volcanic basalt - but volcanism has ceased and in fact the Moon is shrinking as it cools. The reasons that the Moon is so geologically different from the Earth come down to mass. Less mass means less primordial heat trapped in the body as it forms, smaller amounts of radioactive isotopes to generate internal heat, and faster cooling. But wait, I hear you saying. Aren't there active volcanoes on Jupiter's moons? Yes, yes there are. In fact, Jupiter's fourth largest moon, Io, is the most geologically active object in the Solar System, despite being only a little bit bigger than Earth's Moon. But Io is subject to tidal heating - it is in a non-circular orbit around Jupiter, so the changing gravitational forces cause the moon to stretch and squish, which creates friction that heats the interior.* This gives Io a huge amount of internal heat relative to its size. Pluto, on the other hand, is tiny - less than 1/5 the mass of the Moon. Furthermore, it is tidally locked with its largest moon, Charon, so even if either body was large enough to gravitationally deform the other, their orbital configuration makes it impossible. Most scientists were expecting something more like Callisto, I think. Finding out that there are processes operating that are creating new surface layers less than 100 million years old on Pluto has blown people's minds. Where is the heat coming from? Are there cryovolcanoes on Pluto and Charon?** Is there a layer of liquid water under the icy surface? How did these 11,000ft ice mountains form? We don't know. And that's fantastic! *This is a really approximate description of tidal heating, and there's some other interesting physics going on with the interaction of Jupiter's moons. Maybe I'll talk about Laplace resonances later. **When the high-res images come in, they are going to be looking very carefully for plumes from cryogeysers. There was one image that was suggestive, but the guy at the press conference was very careful to say that it was not conclusive evidence.
the only reasons i can think of for pluto to have enough heat to be geologically active would be radioactive material, or a fairly recent major impact that heated everything up and it's still cooling off from that. so fun to think about!
*FALLS HEADFIRST INTO THE THREAD IN MY GENERAL EXCITEMENT* hello science thread!!! resident new biologist-in-training-type here! i'm in the second year of my phd studies, and i'm currently working with the early formation of blood. the general plan is that if we understand how blood develops naturally, we'll have a good way to grow a patient's own marrow in lab conditions, to overcome some of the issues of matching people with the donor pool. this also opens the possibility for genetic modification of the precursory marrow stem cells, giving us a chance to repair genetic conditions and then give people back a healthy version of their own cells. it's pretty rad, and also very sci-fi. this might sound intense but the day-to-day work is fairly eh. i do a lot of dna extractions, and i dissect lots and lots of mouse embryos, hunting for tiny little clusters of cells that are produced in the early aorta. i'm really interested in the role that a cell called megakaryocytes might have in this. these are the cells that produce platelets, and they show up really early in development (~7 days after fertilization, in the mouse). i dunno, i think it's cool. i might be a little bit of a mad scientist.
Oh man, it's not even the oldest one either! http://www.livescience.com/9971-stone-age-carving-ancient-dildo.html And let's not even bring ancient egypt into this. I'm just sporfling at the idea of someone accidentally dropping it while using it.
