Good point. However, I consider the ones I find in my shower in the morning very uncute. In the morning I just want to take a shower, not end up constantly on spider rescue duty!
The only thing I have that I didn't find by googling it is a special issue of National Geographic, which is of the "Hey, general public! Look at how awesome space is!" type, and has less info in it than I have up there. (sorry for taking so long to respond; apparently the 'email me when topic updates' checkbox doesn't work) PS: your member number is 64 and I am slightly jealous. Complete change in topic: wormholes. Spoiler: images! Everyone's seen the representation of the wormhole in 2d: Unfortunately, in the public consciousness this image has been cut-and-pasted into three dimensions, giving us movie wormholes that are ordinary 3d tunnels with 2 circular cross sections, with no explanation as to what the 'walls' are. What the heck is this? Where is the blue light coming from? What happens if I stick my hand in it? Do I fall out of the universe? Does it just stop there, at the edge of space? Nonsense. Fortunately, universities are awesome.
Here, have some fucking awesome science facts I learned in the past few weeks. So y'know Komodo dragons, right? And you know mosasaurs? If you do not know mosasaurs, they were prehistoric relatives of Komodo dragons that lived in the oceans in the Cretaceous and got like 18 meters long and may have looked something like this: Spoiler have some bones, too Anyways, turns out that some degree of venom is ancestral to the lineage of lizards that include Komodo dragons, snakes and these guys. Which means that they may have had at least a weakly venomous bite on top of everything else. Okay, I have no idea what the general background level of info people have on plate tectonics and mid-ocean rifts is (being a geologist-in-training who was raised by a marine biologist), so lemme know if I need to back up and explain some basics if you need context for this, but: There are literally places along ocean rifts that are pulling apart so slowly that instead of a bunch of rock melting and erupting out as lava to make new crust along the rift, the mantle is getting pulled out from under the crust and exposed on the seafloor. Like, that shit's deep, but there's still these giant turtleback-shaped "core complexes" on the ocean floor, where the mantle has been pulled up onto the surface. That's fucking awesome. (there's also some mantle exposed on land, in these things called "ophiolites" -- literally "snake stones," on account of they've got a bunch of serpentine in 'em -- which is where a massive fault has just taken a section of seafloor, oceanic crust, and sometimes the top bit of the mantle and thrown all of it in a stack onto the land. There are some ophiolites where you can go up to where they've been thrown and walk along the boundary between the crust and mantle. These things are also where we get a lot of our information about what the oceanic crust looks like under the surface.) Spoiler: okay this one gets a spoiler because pregnancy squick and some seriously body horror shit So one of the proposed explanations for menstruation in humans and relatives (and in the few bats and shrews where it also occurs; most mammals don't menstruate at all) is that the embryo is so invasive and aggressive the mother has to grow the uterus lining on a schedule (versus in response to the start of a pregnancy, like other mammals) so it's already there to preemptively defend her from her own offspring. And then hormonal changes cause said uterus lining be shed if there's no pregnancy. And then another one gets made. Human reproduction is horrifying. Those mom-skin-eating caecelians ain't got shit on us. If you want more info, here's a science blog article and here's the original paper (which should be publicly accessible via PubMed)
hello I am someone who can 'sperg on brain function and cognitive biases and stuff but I am not good at just pulling out facts on demand so I guess you can ask me questions?
TURBIDITY CURRENT TIME Tagging @jacktrash in this so he can find it when he gets back to the forum, because I think he mentioned that he was interested. So without further ado: What the hell is a turbidity current, anyways? Bit like an underwater landslide. Quite a bit more like an underwater avalanche (actually avalanches are basically just turbidity currents where the surrounding fluid is air). Essentially what happens is you get a bunch of sediment mixed into a volume of water, enough that it stops acting as a bunch of sediment drifting in water and starts acting as a denser-than-water slurry. Being denser than water, this slurry then immediately sets off down the nearest slope. This is where the "turbidity" in the name comes from, actually. Turbidity is a measure of the murkiness of a fluid (a proxy for the amount of sediment and assorted junk in it, basically). It's unrelated to "turbulent," although turbidity currents are also very turbulent (it's part of what keeps all that sediment suspended as a sediment-water slurry), so that gets confusing. Anyways, turbidity currents are super important because they transport a lot of sediment from the continental shelf (where it was originally transported to by rivers and streams) down to the ocean basin (there's these huge delta-like fans all around the bases of all the continental shelves because of them) and make these really distinctive deposits called turbidites in the rock record which have some economic importance (read: oil) and can tell you useful things about the history of the surrounding rock . Oh, and also they've got a bad habit of snapping transcontinental telecommunication lines. They may also be responsible for carving out submarine canyons, but more on that later. Unfortunately, they're really hard to study because A) they're at the bottom of the fucking ocean B) they're hard to predict and over in a few hours, so you can't wait until one's already started and then go try to measure it, and C) if they snap telecommunication lines on the regular, the fuck do you think they're going to do to your delicate, expensive scientific instruments? So this means that we generally have to rely on laboratory models in relatively small tanks, which introduces all sorts of gnarly scaling issues, mathematical models that are hard to double-check except against those laboratory models, maybe some analysis of the turbidite deposits left behind, and the occasional single-point measurement of some variable or another in a turbidity current, generally because some unlucky instrument or cable was in its way. Tune in probably tomorrow for the next installment, featuring Monterey Submarine Canyon and actual goddamn field data (!) Feel free to ask questions. Actually, please please please ask questions. no i'm not using this as an early troubleshooting draft for a paper, that's absurd
Oh man, you know how to catch attention. Your formatting fills me with joy - I saw the bold all-caps title and immediately my brain (which has been trained by three years of reading research studies) went "oh man oh man I am interested" On research methods: people have probably tried this before, but I'm wondering if, say, a bunch of tiny data-recorder things were just tossed out into a turbidity current, if that would gain any useful info? 1. I just realized that I got that from Twister, which is not about the ocean at all 2. I bet enough machines to get any data, with a high amount of loss, would have to be incredibly cheap 3. I should stop borrowing research ideas from movies Now I'm really interested in past research attempts. Are turbidity currents a different temperature from the rest of the ocean?
Well, that runs into point B of Why Turbidity Currents Are Really Fucking Annoying To Study: once you know there's a turbidity current it's generally too late to get out there and take data. Gotta have your instruments/unlucky installations about to be impromptu instruments already in place. (I feel that I should clarify that this is a lit review. I'm not doing original research just yet.) Depends! Usually the temperature's the same as the water around wherever the turbidity current was triggered, because that water just gets entrained into the flow. I suppose if your turbidity current's triggered in shallow, warm water the water within it could be warmer than the surrounding water when it got to depth, but I haven't seen much discussion of that. You apparently sometimes get turbidity currents with flood outwash from rivers that's so loaded with sediment that it's denser than the surrounding seawater, despite fact that the water in the current is warmer and fresher. I think this means you get plumes of buoyant water escaping from the current and rising upward, and dispersing really fine sediments up into the water column that way, but I can't find my source for that right now.
i am indeed fascinated by turbidity currents, and really any large geological processes, particularly erosive ones like glaciers and floods. i assume you've seen this vid already:
That video's actually why I decided to look at turbidity currents for my sed/strat paper! Speaking of which, I should probably get the Monterey Canyon part of that up here too soonish. Also, I dunno if you are familiar with it, but "mass wasting" is the general term for a lot of those those big erosive processes, and also sounds metal as shit. :D
i'm currently getting my BEng (in aerospace!!!!! go space) so my knowledge is less natural things & more tech stuff but here goes: Spoiler: lotta links + large image wearable robotics (in the near future, it looks like)!! nanoscale objects brought to macroscale for your viewing pleasure! superfast helicopter goes very very slowly 3d printer repurposed for pancakes really big jellyfish (over a meter across!) they've also found stone tools that predate the previous oldest ones by 70000 years! the turbidity currents look super cool. i know next to nothing about fluid dynamics, so the answer to this question might be way out of my league, but what kind of scaling issues are there when studying the lab models?
they're so cool & also creepy, somewhere there's a photo of a diver next to one and it dwarfs him (i can't find it for the life of me though) a different kind was filmed trying to grab science equipment: linky (also unrelated but here's a vid of a deepstaria)
how about some archaeology? redheaded mummies in china! what were europeans doing in the tarim basin? why did they go there? were they running from something, or were they nomadic and then decided to settle, or did the silk road start in 2k bc? i find their textiles especially fascinating. so colorful! look at his stripey felt socks! look at his maroon robe! they got that purply red by dyeing red over natural gray wool. textbook images of prehistoric people tend to show them wearing shapeless garments of brown sacking, but whenever we find a well-preserved bit of early textile, it's brightly colored and skillfully made. i think we need to revise our assumptions about what ordinary people wore even in the stone age. it's not as if joe random goat-herder couldn't easily pick enough yarrow or walnut husks or whatever to dye his coat with. and anywhere that has winter is going to have a textile tradition, because you can't go naked and you can't sleep 18 hours a day when it's cold and dark so you have to do something to pass the time.
@jacktrash That is one fashionable mummy. It's really interesting to think about. Why does everybody think of ancient people just wearing boring stuff?
i think the image of the standard brown clothing came from the clothes not always retaining the original colours or being well preserved (maybe also an assumption that really early people wore leather/furs/hides all the time?). the well preserved sections of the cloths should have dispelled that, though, but ?? i dunno. sometimes things just stick despite there being evidence to the contrary. no idea where the idea of shapeless clothes being the norm in prehistory came from. i do 100% agree that we need to revise assumptions! also, i want some socks like that. they look very warm & fuzzy even now
maybe No Concept of Fashion makes prehistoric times seem more prehistoric too... like, "so long long ago, they haven't invented style yet"
Sorry, I've been meaning to respond to this for a bit, but I kept not getting around to it. I should also post the Monterey Canyon bit of my turbidity current paper up here sometime. :x The most obvious issue is that your grain sizes with respect to your flow are wayyy different. So silt in a lab tank is a lot coarser grained with respect to the size of the flow when compared to silt in a 200m high turbidity current, but it still settles out of suspension like silt, and not like a cobble in the big turbidity current that's proportionally the same size with respect to the size of the flow. If that makes sense? So if you try to go for the right proportional size you fuck up your settling rate and if you try to go for the right settling rate you fuck up your concentrations, particle sizes relative to the flow and particle-particle interactions and whatnot. Turbulence also apparently behaves differently at different scales, although I don't know the details of that. I do know that viscosity and whatnot starts behaving really differently at small scales. Zooplankton like copepods don't really swim through water, they crawl. Also, bedforms don't scale well. Would those ripples you got in your lab tank be larger dunes in a full-sized turbidity current, or just ripples of about the same size? (given that dunes vs ripples is controlled mostly by current velocity) Essentially, laboratory models will get you the basic shape/physics/fluid dynamics of turbidity currents, but don't really tell you anything about sediment transport or deposition. Which is what I'm actually interested in, given that I'm looking at this as a sedimentologist. #there may also be some shenanigans with the froude number and reynolds number #but that's a bit out of my depth when it comes to fluid dynamics
The LHC is back in action! Live monitoring: https://op-webtools.web.cern.ch/op-webtools/vistar/vistars.php (warning: terrible graphic design)
