[HN Gopher] Draw an iceberg and see how it will float
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Draw an iceberg and see how it will float
Author : mabynogy
Score : 341 points
Date : 2024-06-08 22:04 UTC (1 days ago)
(HTM) web link (joshdata.me)
(TXT) w3m dump (joshdata.me)
| Gunax wrote:
| Very cool, simple, and easy. This is exactly what demos should
| be.
| tedunangst wrote:
| Not so easy to get just the tip of the iceberg to stand out.
| o11c wrote:
| 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 wrote:
| A very flat triangle with convex flanks does the job
| ant6n wrote:
| Draw a fat boat with a very thin long mast.
| nick7376182 wrote:
| Would be cool if it melts preferentially, choosing either air or
| water to be "warmer".
| blackoil wrote:
| For me multiple humps seems to be most stable
| mrcwinn wrote:
| I'm so over flappy birds now.
| jsnell wrote:
| (2021)
|
| https://news.ycombinator.com/item?id=26201160
| alphanumeric0 wrote:
| This reminds me of gomboc
| arun-mani-j wrote:
| Very cool (literally) stuff. I drew a straight line and it keeps
| spinning :D
| mhatma wrote:
| This is very entertaining.
| GeorgeRichard wrote:
| This is great fun--and accurate. My lettuce floated just like the
| picture I drew when I tested it in the bath.
| xg15 wrote:
| I know you should wash lettuce before eating, but that seems
| like overkill...
|
| (jk)
| xg15 wrote:
| 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 wrote:
| Here's a non-flat one:
|
| https://imgur.com/a/7KANxOn
|
| Very unlikely to occur in nature I guess :-)
| xanderlewis wrote:
| https://ibb.co/ZLYxr4x
|
| Sometimes to innovate you have to think like a child -- or a
| teenager.
| rvnx wrote:
| Make sure to patent it before they use this as base design
| for the Cybertruck^2
| isoprophlex wrote:
| Nice tip on that iceberg
| barfbagginus wrote:
| I was about to post something similar. But you nailed it
| before I could swing my own hammer, to use a figure of
| speech.
| barfbagginus wrote:
| I was about to post something similar. But you nailed it
| before I could swing my own hammer, to use a figure of
| speech.
| HarHarVeryFunny wrote:
| 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.
| Sharlin wrote:
| That's exactly it. An iceberg can't stay "vertical" for the
| exact same reason that a pencil can't stay vertical. Even if
| perfectly balanced, the equilibrium is unstable.
| WhitneyLand wrote:
| Try something that has no flat surfaces. For example a five
| pointed star.
| furyofantares wrote:
| Hexagons work
| RobertRoberts wrote:
| I drew an equilateral triangle and it floats flat on top.
| praptak wrote:
| 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.
| Obscurity4340 wrote:
| This would make a great "fidget" app
| joshdata wrote:
| Author here. Glad to see this making the rounds again after a few
| years.
|
| Go science! Support your local climate scientist!
| _Microft wrote:
| 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.
| cscurmudgeon wrote:
| 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.
| joshdata wrote:
| I am pretty sure it's the simulation.
| jackspratts wrote:
| nice job. these simulations are 2d. does 3d make a difference?
| i'm almost about to start carving styrofoam to see.
|
| - js.
| miduil wrote:
| Kinda funny to draw the classic examples of "tip of the iceberg"
| to see them ending up flipping :D
| ljsocal wrote:
| It would be interesting to create a version of this that would
| show how different displacement hull shapes would float.
| barfbagginus wrote:
| 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
| sinuhe69 wrote:
| I got a design which wobbles infinitely! :D The clip was live
| recorded, not looped.
|
| https://streamable.com/0a9zmb
| Dunati wrote:
| It seems to have trouble with long skinny shapes, I had one
| that would keep moving and occasionally flip over
| madcaptenor wrote:
| 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.
| personalityson wrote:
| Bug? https://i.imgur.com/VraUTnq.png
| taneq wrote:
| 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.
| talkingtab wrote:
| My fun was to try to get the widest underwater part with the
| narrowest top showing above.
| squarefoot wrote:
| 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 wrote:
| 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)
| amelius wrote:
| Now let a polar bear walk on it.
| amelius wrote:
| 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 wrote:
| There isn't necessarily just one. A rectangle-ish form could
| have 4.
| amelius wrote:
| Yes, rectangle would also be degenerate. Basically any
| configuration where adding an epsilon weight somewhere
| generates a non-epsilon shift so to speak.
| marcosdumay wrote:
| You mean unstable?
| sa46 wrote:
| 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.
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(page generated 2024-06-09 23:01 UTC)