4 ms·

The mysterious balancing stones on frozen lakes

121 points by sohkamyung 4y ago

rob74 4y ago
Cool! I guess this only works with stones where the center of gravity is more or less the same as the geometric center (or more likely, the point where the shadow is the strongest, which may not be the geometric center depending on the angle of the sun).
- mikewarot 4y ago
  This phenomenon[1] which you can use to find the center of gravity of an object might greatly increase the number of stones that work. [1] https://www.exploratorium.edu/snacks/center-gravity https://www.exploratorium.edu/snacks/center-gravity
dendrite9 4y ago
I was unable to find any pictures of penguin bodies on pedestals of ice as mentioned at the end. Even though it happens the same way I'm curious to see what that looks like. Ars technica wrote about an earlier version of this research a year ago, it seemed familiar. https://arstechnica.com/science/2021/09/physicists-may-have-cracked-the-case-of-zen-stones-balanced-on-ice-pedestals/ https://arstechnica.com/science/2021/09/physicists-may-have-...
hansjorg 4y ago
The pictures made me think of this: https://www.physics.utoronto.ca/~smorris/edl/icespikes/icespikes.html https://www.physics.utoronto.ca/~smorris/edl/icespikes/icesp...
- dendrite9 4y ago
  Oh that is interesting. There also are ice ribbons, flowers and needle ice. The ice flowers seem to be created by a similar mechanism but the hole is in a plant rather than the top of a container of water. https://www.americanscientist.org/article/flowers-and-ribbons-of-ice https://www.americanscientist.org/article/flowers-and-ribbon...
l0b0 4y ago
Reminded me of this[1]: leaves (and a stick in the background) creating a "rain shadow" on a river beach, resulting in sand pedestals. [1] https://secure.flickr.com/photos/l0b0/50830815242/ https://secure.flickr.com/photos/l0b0/50830815242/
- rob74 4y ago
  That's the "hoodoo mechanism" which is also mentioned in the article: on a bigger scale, when you have a layer of harder rock on top of softer rock, you get hoodoos (also called earth pyramids or tent rocks): https://en.wikipedia.org/wiki/Hoodoo_(geology) https://en.wikipedia.org/wiki/Hoodoo_(geology)
  - l0b0 4y ago
    Nice, TIL. I wonder if there's a name for these ephemeral sand formations, as hoodoos seem to be more permanent.
GavinAnderegg 4y ago
The article mentions reproducing this under careful lab conditions, but I reproduced this accidentally in my freezer. A few years ago, there were a series of storms that were likely to knock out power in my area. This had happened before, and I worried about food spoiling in my freezer. So I froze water in a plastic container, and (once frozen solid) I placed a coin on top. The thinking was: if the freezer thaws enough for the coin to drop into the ice, I may have spoilage. This never happened, but the ice around the edges of the coin slowly receded leaving the coin “balancing” on a spire of ice. This happened over the course of several weeks. Give it a shot yourself!
- dicknuckle 4y ago
  I had the same exact phenomenon. Bought a freezer for my garage and immediately did the coin-on-ice trick for a week before using it and then checked again 2 months later and found the strange position of the coin.
- mikewarot 4y ago
  This means that ANY OF US can be at the leading edge of science, as long as we have a freezer. [on further consideration] Seriously, this unexplored corner of physics is like being in the position of Henry Cavendish when he first weighed the earth.[1] You could use an PC with a web cam, and some lights, fans, heaters, etc... to try all sorts of experiments to see what the causes of this phenomenon are. Its rare to find such unexplored corners of knowledge that are so easily reached by a single experimenter. [1] https://en.wikipedia.org/wiki/Cavendish_experiment https://en.wikipedia.org/wiki/Cavendish_experiment
  - zionic 4y ago
    Depending on the sharpness of the spire, it may even be the cutting edge!
  - hnuser123456 4y ago
    Well, the knowledge gained from the balancing stones might be as impressive as learning the density of earth at the time, but I wonder how hard it would be to explain "ice can evaporate without melting first, and everything is always faintly glowing with a type of warm light that you can't see, and can also cast shadows you can't see..."

121 points by sohkamyung 4y ago

Cool! I guess this only works with stones where the center of gravity is more or less the same as the geometric center (or more likely, the point where the shadow is the strongest, which may not be the geometric center depending on the angle of the sun).

mikewarot 4y ago
This phenomenon[1] which you can use to find the center of gravity of an object might greatly increase the number of stones that work. [1] https://www.exploratorium.edu/snacks/center-gravity https://www.exploratorium.edu/snacks/center-gravity

dendrite9 4y ago

I was unable to find any pictures of penguin bodies on pedestals of ice as mentioned at the end. Even though it happens the same way I'm curious to see what that looks like. Ars technica wrote about an earlier version of this research a year ago, it seemed familiar. https://arstechnica.com/science/2021/09/physicists-may-have-cracked-the-case-of-zen-stones-balanced-on-ice-pedestals/ https://arstechnica.com/science/2021/09/physicists-may-have-...

hansjorg 4y ago

The pictures made me think of this: https://www.physics.utoronto.ca/~smorris/edl/icespikes/icespikes.html https://www.physics.utoronto.ca/~smorris/edl/icespikes/icesp...

dendrite9 4y ago
Oh that is interesting. There also are ice ribbons, flowers and needle ice. The ice flowers seem to be created by a similar mechanism but the hole is in a plant rather than the top of a container of water. https://www.americanscientist.org/article/flowers-and-ribbons-of-ice https://www.americanscientist.org/article/flowers-and-ribbon...

l0b0 4y ago

Reminded me of this[1]: leaves (and a stick in the background) creating a "rain shadow" on a river beach, resulting in sand pedestals. [1] https://secure.flickr.com/photos/l0b0/50830815242/ https://secure.flickr.com/photos/l0b0/50830815242/

rob74 4y ago
That's the "hoodoo mechanism" which is also mentioned in the article: on a bigger scale, when you have a layer of harder rock on top of softer rock, you get hoodoos (also called earth pyramids or tent rocks): https://en.wikipedia.org/wiki/Hoodoo_(geology) https://en.wikipedia.org/wiki/Hoodoo_(geology)
- l0b0 4y ago
  Nice, TIL. I wonder if there's a name for these ephemeral sand formations, as hoodoos seem to be more permanent.

GavinAnderegg 4y ago

The article mentions reproducing this under careful lab conditions, but I reproduced this accidentally in my freezer. A few years ago, there were a series of storms that were likely to knock out power in my area. This had happened before, and I worried about food spoiling in my freezer. So I froze water in a plastic container, and (once frozen solid) I placed a coin on top. The thinking was: if the freezer thaws enough for the coin to drop into the ice, I may have spoilage. This never happened, but the ice around the edges of the coin slowly receded leaving the coin “balancing” on a spire of ice. This happened over the course of several weeks. Give it a shot yourself!

dicknuckle 4y ago
I had the same exact phenomenon. Bought a freezer for my garage and immediately did the coin-on-ice trick for a week before using it and then checked again 2 months later and found the strange position of the coin.
mikewarot 4y ago
This means that ANY OF US can be at the leading edge of science, as long as we have a freezer. [on further consideration] Seriously, this unexplored corner of physics is like being in the position of Henry Cavendish when he first weighed the earth.[1] You could use an PC with a web cam, and some lights, fans, heaters, etc... to try all sorts of experiments to see what the causes of this phenomenon are. Its rare to find such unexplored corners of knowledge that are so easily reached by a single experimenter. [1] https://en.wikipedia.org/wiki/Cavendish_experiment https://en.wikipedia.org/wiki/Cavendish_experiment
- zionic 4y ago
  Depending on the sharpness of the spire, it may even be the cutting edge!
- hnuser123456 4y ago
  Well, the knowledge gained from the balancing stones might be as impressive as learning the density of earth at the time, but I wonder how hard it would be to explain "ice can evaporate without melting first, and everything is always faintly glowing with a type of warm light that you can't see, and can also cast shadows you can't see..."