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Mexican jumping beans use random walk strategy to find shade: study
- JKCalhoun 4y agoApplied Science recently pointed his X-ray video hardware at the Mexican jumping bean: https://youtu.be/xdpDd7dyU00?t=33 https://youtu.be/xdpDd7dyU00?t=33
- graderjs 4y agoAmazing good quality high-speed x-ray video!
- memalign 4y agoInteresting video. I can’t believe this guy is just live x-raying his fingers like this though…
- aliqot 4y agothey come in packs of ten for a reason yaknow!
- blamazon 4y agoSleep soundly, for Ben is no stranger to radiation and imaging and is surely well aware of the risk profile. He mentions it briefly at 10:55 as roughly equivalent to a dental X-ray, which is pretty minor as seen on the excellent XKCD radiation dose visualization: https://xkcd.com/radiation/ https://xkcd.com/radiation/ If I recall correctly Ben's side hustle before YouTube was making non-ferrous computer peripherals for MRI machines, and his portfolio on YouTube is incredibly extensive including this one from 10 years ago where he made a CT scanner from scratch! https://youtu.be/hF3V-GHiJ78 https://youtu.be/hF3V-GHiJ78
- ge96 4y agoI was amazed with the lcd and the vacuum metal evaporation coat applying thing
- ballenf 4y agoAlways amazed at the order of magnitude jumps in that chart. Why are mammograms 20x stronger than chest x-rays? Who would guess how much safer the nuclear energy stuff is than so many common activities? And brick/stone house doses are kind of astounding. Even after examining that chart every few years, my intuition still isn't tuned to reality.
- meghan_rain 4y agoAnyone know if this can realistically cause cancer or skmething?
- 13of40 4y agoPresumably they've refined the equipment by now, but this guy seriously injured his hands with x-rays around the turn of the previous century: https://en.wikipedia.org/wiki/Mihran_Kassabian https://en.wikipedia.org/wiki/Mihran_Kassabian
- persedes 4y agoAlways wondered about that too. Once got a contrast solution injected into my shoulder (they were going for the tissue around the joint) under a live x ray feed and I could watch them on a screen. I was padded with lead wherever possible, but still, cool experience.
- spookthesunset 4y agoThat guy doesn’t get enough props for what he puts out, in my opinion…
- graderjs 4y agoA moth in a womb kicking about until it gets comfortable? That's pretty cool.
- deleted 4y ago[deleted]
- ogoparootbbo 4y agoerr, I maybe hugely mistaken but is this an example of a real life of the following joke: "a scientist had this experiment going wherein everytime he rung a bell the grasshopper would jump. He clips one of the grasshopper's legs and rings the bell to see if the grasshopper would still jump and it did. He repeated the clipping process till the grasshopper had no legs. He wondered if it would still jump ... and it did not. He muttered to himself that hence that proves grasshoppers use their legs to hear" am wondering it this is an example of a teleological thinking?
- phirus 4y agoYes "random walk" is not a strategy, it is a model. This article basically just says:"Jumping bean motion can be modeled with random walk", which isn't really suprising.
- ars 4y agoYah, this article is basically nonsense. The beans jump more when hot, and less when cold, meaning they are more likely to stay put when jumping into the shade, and if too hot they'll keep jumping.
- yipbub 4y ago"These results suggest that diffusive motion [random walks] in Mexican jumping beans does not optimize for finding shade quickly," the authors concluded. "Rather, Mexican jumping beans use a strategy that minimizes the chances of never finding shade when shade is sparse."
- jameshart 4y agoI’m not sure what alternative strategy they are hypothesizing that would find shade more quickly, though? it seems like the bugs have only one motor function - move in a random direction - and only one input sensor - temperature. What other strategies are available to them than random walk with a probability of movement based on a function of temperature and time?
- ars 4y agoThis not true: "Because the outcome of each coin flip is independent of all the others, there is always an equal chance that it will land on heads or tails with each toss. That means that your future final position is independent of your original starting position" Assuming a fair coin, you will most likely end up approximately at where you started, with a Gaussian distribution. And your final position is extremely correlated with where you started.
- alar44 4y agoIn theory, using spherical cows, sure. But in practice there are all sorts of things screwing up the "probability" when jumping. Slope of the ground, windspeed, ground cover, etc.
- HPsquared 4y agoThen it's still dependent on some known inputs: final position depends on initial position, wind speed/direction, ground conditions and gradient, etc etc. There is randomness, but you could make a probability distribution.
- alar44 4y agoOk? But it won't just converge to 0,0 because everything isn't equal and opposite, there will be some sort of bias that will move the bean away from it's origin.
- ballenf 4y agoBut once you move to 3-dimensions, with a 3-sided coin that isn't true any more.
- hgsgm 4y agoYes it is true. You may be misremembering the fact that an infinite walk in 3D has less than 1 probability of returning to start. But returning to start is still the most likely outcome. How could anything else be more likely? https://mathworld.wolfram.com/RandomWalk3-Dimensional.html https://mathworld.wolfram.com/RandomWalk3-Dimensional.html
- ipaddr 4y agoNot understanding how this is the best strategy to find success. A straight direction would be quicker and travel further.
- RC_ITR 4y agoSpeed and distance aren’t what is being solved for. Maximizing the chance of hitting an arbitrary spot is.
- Xylakant 4y agoA straight line would require that you know where to go. But the bean (or rather it’s occupant) doesn’t - it has no eyes to look outside. So essentially it decides “it’s uncomfortably warm, let’s go elsewhere” until it’s no longer uncomfortable.
- Y_Y 4y agoI see what you mean, but it's not necessarily true. You could pick an initial direction and keep jumping that way. I don't know what kind of environment would favour this behaviour, or if the beans can "jump the same way as last time" but it's certainly plausible.
- The_Colonel 4y agoAgreed, but the bean would probably very quickly find an obstacle over which it cannot jump. It would have to change direction then, but that's a much more complex strategy. Another problem is that the bean probably can't keep a direction even if it "wanted". It uses random walk, quite possibly because it's the simplest to achieve acceptable results.
- Y_Y 4y agoSo you're saying we should CRISPR in some pigeon magnetic direction finding genes to the jumping beans so that they have more choice in their shade-finding strategy?
- Proven 4y ago[dead]
- intrasight 4y agoNow I await someone pointing a camera at one - to create a random number generator like is done with lava lamps.
- h2odragon 4y agoThey don't really live that long. They can be farmed, I gather it's a couple difficulty steps above "regular" moth ranching.
- bookofjoe 4y agohttps://news.ycombinator.com/item?id=34748479 https://news.ycombinator.com/item?id=34748479
- astannard 4y agoI need glasses, I thought it was a species of bear I'd not heard of that likes to jump.
- h2odragon 4y agoJumping beans are available for purchase. I haven't bought from these folks; but I've heard good reviews of them: https://www.amazingbeans.com/ https://www.amazingbeans.com/
- wearsshoes 4y agoKarl Friston mentions a similar discovery in this interview: https://www.aliusresearch.org/uploads/9/1/6/0/91600416/friston_-_of_woodlice_and_men.pdf https://www.aliusresearch.org/uploads/9/1/6/0/91600416/frist... “I first came up with a prototypical free energy principle when I was eight years old, in what I have previously called a “Gerald Durrell” moment (Friston, 2012). I was in the garden, during a gloriously hot 1960s British summer, preoccupied with the antics of some woodlice (small armadillo like bugs—see Figure 1) who were frantically scurrying around trying to find some shade. After half an hour of observation and innocent (childlike) contemplation, I realized their “scurrying” had no purpose or intent: they were simply moving faster in the sun—and slower in the shade. The simplicity of this explanation—for what one could artfully call biotic self-organization—appealed to me then and appeals to me now. It is exactly the same principle that underwrites the ensemble density dynamics of the free energy principle—and all its corollaries.” I wonder if the simplicity of his proposed wood lice model applies to the jumping bean larvae as well?