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Draw an iceberg and see how it would float in water

joshdata.me

161–170 of 179 posts

Re: Draw an iceberg and see how it would float in water

#164

So without any further knowledge about how icebergs should orient and how scientists draw them: Icebergs in 3D will generally have different mass distributions than the corresponding 2D projections that we are drawing here. For example, there will generally be higher "2D mass density" in the center. Consequently, it is possible that the scientists "drawing icebergs wrong" are actually right and it just looks/"behaves…

This kind of drawing matches early year mechanical engineering courses.

The generalizations are to add density distributions and the 3rd dimension.

The math generalizes just fine for picking points that are stable. The motion on how it gets there relies on the full Navier Stokes vs the simplifications, so I wouldn't trust that you've actually gotten to the right stability point

Re: Draw an iceberg and see how it would float in water

#165
post #89

The algorithm doesn't seem to be complete, it can't handle concave shapes with trapped water or trapped air. But that's probably too much to ask. Edit: to illustrate the point, this iceberg had trapped air before it stabilized and removed all air, which is physically impossible: https://imgur.com/a/uiaW1qN

on the one hand, this is clearly a 2D simplification of a 3D problem.

on the other... if you imagine your spiral as projecting outward a non-infinite distance, how could it possibly "trap" air? the air would flow toward (and away from) the viewing plane very quickly.

Re: Draw an iceberg and see how it would float in water

#166
post #89

The algorithm doesn't seem to be complete, it can't handle concave shapes with trapped water or trapped air. But that's probably too much to ask. Edit: to illustrate the point, this iceberg had trapped air before it stabilized and removed all air, which is physically impossible: https://imgur.com/a/uiaW1qN

on the one hand, this is clearly a 2D simplification of a 3D problem. on the other... if you imagine your spiral as projecting outward a non-infinite distance, how could it possibly "trap" air? the air would flow toward (and away from) the viewing plane very quickly.

Yes but surely concavities with trapped air are possible in real life? Not necessarily in the form of a spiral.

Re: Draw an iceberg and see how it would float in water

#170

Earlier quoted context omitted.

I think this was patched just now. On my last visit a few minutes ago the bug still worked, now it removes any larger bits where the lines intersect. Also, the code has been amended right where this comment is: // People like to draw shapes with kinks, which results // in part of the polygon being treated as negative area. // turf.unkinkPolygon can be used to find the kinks and // separate the polygon into multiple p…

You may want to revert the (tedious) patch about intersections. Here is a simple workaround: > turf.unkinkPolygon=(x)=>x; Press F12, click 'Console', copy-paste the above one and press Enter.

I'm having so much fun with the before-the-fix version, you can make it "jump" out of the water, if you draw a figure 8 under water, and when the negative lobe is at the top and around 75% of the size of the positive one

Even more optimal: https://imgur.com/7gCEJ0T

I've had more extreme versions of this shape teleport off-screen, when starting them under water: https://imgur.com/ymVtTWq

And here's someone holding a balloon: https://imgur.com/8O4rib8

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