7 ms·
Not that large
by stoops 7y ago
Not that large
- 40four 7y agoI don’t know the earth is pretty big :) It is a near perfect circle, as are all the other planets & moons we observe. Maybe the rings of Saturn? Just kidding around really, but I have to imagine that pockets of circular water currents like this, are more common than we would think. We just can’t easily observe the dynamics of water flow until something like this happens, where a bunch of ice builds up and makes it obvious.
- ergothus 7y agoThe earth is pretty lumpy, what with mountains and oceans, and the earth is where I learned the term "oblate spheroid".
- Talanes 7y agoLess lumpy than a billiard ball. The mountains and trenches only seem significant because the whole thing is so big. Totally not a perfect sphere though, yeah.
- scbrg 7y ago> Less lumpy than a billiard ball. Well, no: https://ourplnt.com/earth-smooth-billiard-ball/ https://ourplnt.com/earth-smooth-billiard-ball/ The myth is springs from the fact that if you had a smooth earth with a radius of center to Mariana Trench, and another smooth earth with a radius of center to Mt. Everest, you could shrink both of them by the same factor and fall within allowed billiard ball specifications. That says nothing about smoothness, only about the allowed size of ball. If you actually shrunk the earth we're living on, the ball would still be rejected as quite too rough.
- djmips 7y agoIf you shrunk the earth down to the size of a billiard ball and the imperfections where only as rough as the bumps in medium sandpaper then that's still pretty darn round even if it wouldn't be acceptable under official billiard ball specifications. I never could get behind the idea that it would be smooth as a billiard ball but to know you could feel the ridges is pretty neat and yet it's very very round.
- danwills 7y agoA near-perfect sphere? sure! Only looks-like-a-circle from some distant projection. Vortices in a near-2d-flow like a river will absolutely be circular, vortices need to be coherent in some plane in order to sustain themselves. The specific circumstances here must be that that the water is on the edge of freezing during downstream flow and there is a naturally-very-long-lived vortex in one region for it to initially form the ice-disc. Must also be followed by some very-gently-bounceing-off-the-edges, and the river never getting too thin for it to get stuck.
- fctorial 7y agoEarth is a disk?
- imron 7y agoOn the back of 4 elephants, then it's turtles all the way down.
- saalweachter 7y agoOne turtle, and everyone is very worried about the order a second would be added in.
- cgriswald 7y agohttps://en.m.wikipedia.org/wiki/Saturn's_hexagon https://en.m.wikipedia.org/wiki/Saturn's_hexagon > Saturn's hexagon is a persisting hexagonal cloud pattern around the north pole of the planet Saturn, located at about 78°N.[1][2][3] The sides of the hexagon are about 14,500 km (9,000 mi) long,[4][5][6][7] which is more than the diameter of Earth[8] (about 12,700 km (7,900 mi).
- codetrotter 7y agoWhy do the two photos at the top of that article look so weird? They look like 3D renders almost. Is that what it actually looks like to the eye too, if one looked at Saturn from a spacecraft orbiting around it?
- yorwba 7y agoThey look like bad 3D renders because there are no walls and no sky in space, so all the light comes directly from the sun and shadows are absolutely black. The image looks different than with the naked eye though, because they filtered certain wavelengths. https://www.nasa.gov/jpl/cassini/pia18274 https://www.nasa.gov/jpl/cassini/pia18274
- est31 7y agoThe question is legitimate though as sometimes we do get 3D renders, e.g. when it comes to this image of the Korolev crater on Mars: https://www.esa.int/var/esa/storage/images/esa_multimedia/images/2018/12/perspective_view_of_korolev_crater/18938178-1-eng-GB/Perspective_view_of_Korolev_crater_pillars.jpg https://www.esa.int/var/esa/storage/images/esa_multimedia/im... They even added the fog (the fog in the picture is white and while there is dust on mars it's rather brown as the planet's surface https://mars.nasa.gov/imgs/mep/weather/PIA22520-600.jpg https://mars.nasa.gov/imgs/mep/weather/PIA22520-600.jpg ).
- mkl 7y agoShadows in space are often very high contrast, as there's no ambient light. Simple 3D renderers don't handle ambient light either, as simulating it can be very computationally expensive (instead of e.g. one light source, pretty much everything in the scene acts as a light source with the light it reflects). These images in particular are also in near-infrared, so they may look a little different to colour images of Saturn you've seen.
- fctorial 7y agoMilky way?
- JoBrad 7y agoIt’s kind of difficult for any human to observe the circular shape of the Milky Way.
- _bxg1 7y agoI think what you mean is "not that medium". You can find this sort of shape at the astronomic and the microscopic scales, just not usually at human scale.