Draw an iceberg and see how it will float

[xg15]

Got a bit frustrated because I couldn't get anything except a flat surface above the water, then read the tweets below and realised that's the entire point:

https://threadreaderapp.com/thread/1362557149147058178.html

(Many thanks to Elon for making it impossible to read more than the first tweet on x.com without an account...)

[ajb]

Here's a non-flat one:

https://imgur.com/a/7KANxOn

Very unlikely to occur in nature I guess :-)

[HarHarVeryFunny]

My mental model is of each side (think left/right in 2-D) of the iceberg competing with the other side to float to the surface by rotating the iceberg around it's center of gravity. The only stable positions are where these left/right rotational forces are balanced.

If an iceberg is currently floating in a vertical orientation where more of it's mass to one side of it's center of gravity (bottom half) is underwater compared to the mass on the other side (top half), then it's going to tend to rotate until both sides are equally above water, so (depending on mass distribution) horizontal orientations are likely to win over vertical ones.

Of course an iceberg could balance vertically, but that's like balancing a pencil on your finger - not the most stable, and any disturbance (such as the initial calving event) is likely to rotate it into a more stable horizontal orientation.

[kazinator]

https://i.imgur.com/ixBkSsV.png

[JadeNB]

> (Many thanks to Elon for making it impossible to read more than the first tweet on x.com without an account...)

https://threadreaderapp.com/thread/1362557149147058178.html

[WhitneyLand]

Try something that has no flat surfaces. For example a five pointed star.

[RobertRoberts]

I drew an equilateral triangle and it floats flat on top.

[furyofantares]

Hexagons work

[joshdata]

Author here. Glad to see this making the rounds again after a few years.

Go science! Support your local climate scientist!

[cscurmudgeon]

Great education simulation! Thanks for working on this.

Curious about this: I am hitting a boundary-condition like behavior drawing a straight line at a 45 degree angle similar to the sibling comment.

Curious if it is due to physics or due to the simulation.

[_Microft]

This is very cool.

I found shapes that do not work well with the simulation: a very wide and narrow shape (like a needle) oscillates wildly and does not seem to stop or to even slow down.

[jackspratts]

nice job. these simulations are 2d. does 3d make a difference? i'm almost about to start carving styrofoam to see.

- js.

[sinuhe69]

I got a design which wobbles infinitely! :D The clip was live recorded, not looped.

https://streamable.com/0a9zmb

[sinuhe69]

My son even beat me with a better design, which is wobbling and bobbing like crazy :)

https://jmp.sh/s/ARfqurF7BYQExwIQmWXZ

[Dunati]

It seems to have trouble with long skinny shapes, I had one that would keep moving and occasionally flip over

[madcaptenor]

A version which has some preloaded shapes and shows the forces explicitly, inspired by the same tweet: https://engaging-data.com/iceberger-remixed/

This is all from 2021 and I feel like I’d seen this prior to that but I can’t find it.

[sa46]

The HTML source code is a well-commented, fun read.

- There's a fair bit of math to model drag, mass, and density using the specific gravity of ice and seawater (with tweaks to make it more realistic for 2d).

- Try adding a polygon that overlaps itself (self-intersects).

- You can paste images! The code traces the image and picks the most complex polygon.

[GeorgeRichard]

This is great fun--and accurate. My lettuce floated just like the picture I drew when I tested it in the bath.

[xg15]

I know you should wash lettuce before eating, but that seems like overkill...

(jk)

[jsnell]

(2021)

https://news.ycombinator.com/item?id=26201160

[squarefoot]

No idea if others at Twitter suggested this as I can't read the thread (and have no intention to subscribe) but a nice add on would be a score inversely proportional to the travel an iceberg would need to obtain a stable floating position, with ideally the very hard goal to draw it already in a perfect stable way, waterline height included.

[Someone]

It isn’t too hard to get fairly close to that by drawing something that’s extremely stable, for example something very wide but not tall or an equilateral triangle, with one corner facing down.

Then, use your first attempt to correct for the correct height.

⇒ I think a good game would need some other constraint, maybe score more for max height above the surface, or for how long a polar bear can keep their feet dry while it melts (a very wide but not tall stripe will melt faster than something resembling a ball)

[arun-mani-j]

Very cool (literally) stuff. I drew a straight line and it keeps spinning :D

[miduil]

Kinda funny to draw the classic examples of "tip of the iceberg" to see them ending up flipping :D

[praptak]

The center of displacement is always below the center of mass, so the iceberg never gets the stability of a rock hanging on a thread (ships can do that with ballast).

The only way for an iceberg to achieve stability is "differential" - every infinitesimal movement needs to move the center of displacement in a way which counters the movement. This basically means flat bottom.

[kazinator]

https://i.imgur.com/z7mQVWq.png

https://i.imgur.com/YLPYITL.png

https://i.imgur.com/Q7T0zns.png

[tedunangst]

Not so easy to get just the tip of the iceberg to stand out.

[o11c]

Try drawing a "^" shape. The fundamental constraint is that the iceberg hates going too deep; with the two legs, any rotation would force that and is thus forbidden.

A flat bottom can almost work but is highly prone to accidental asymmetry.

[navane]

A very flat triangle with convex flanks does the job

[ant6n]

Draw a fat boat with a very thin long mast.

[mrcwinn]

I’m so over flappy birds now.

[kromokromo]

To the author: Would be interesting to store all the shapes people are creating and let us quickly browse through them.

Mostly penises most likely (like any "draw something online" service).

(I am also guilty)

[joshdata]

Yeah, I don't want to be responsible for user-generated content, and I don't want to collect data on users.

[mhatma]

This is very entertaining.

[taneq]

From my brief experimentation I have determined that the precise initial orientation of the dick^H^H^H^Hiceberg is critical to its final orientation.

[amelius]

How do we know there is only 1 stable position?

(A perfect circle would have many, but you could consider that a degenerate configuration.)

[eternauta3k]

There isn't necessarily just one. A rectangle-ish form could have 4.

[ljsocal]

It would be interesting to create a version of this that would show how different displacement hull shapes would float.

[blackoil]

For me multiple humps seems to be most stable

[nick7376182]

Would be cool if it melts preferentially, choosing either air or water to be "warmer".

[talkingtab]

My fun was to try to get the widest underwater part with the narrowest top showing above.

[alphanumeric0]

This reminds me of gömböc

[Gunax]

Very cool, simple, and easy. This is exactly what demos should be.

[Obscurity4340]

This would make a great "fidget" app

[personalityson]

Bug? https://i.imgur.com/VraUTnq.png

[amelius]

Now let a polar bear walk on it.

[barfbagginus]

Note that many icebergs have more than one equilibrium, with various final heights above the water.

For example this iceberg towers above the water in one equilibrium, but barely rises above the water in its other equilibrium.

https://ibb.co/SdcKMBV