[HN Gopher] Cats in zero-g lose their auto-righting reflex (2011... ___________________________________________________________________ Cats in zero-g lose their auto-righting reflex (2011) [video] Author : carabiner Score : 131 points Date : 2022-04-11 15:57 UTC (7 hours ago) (HTM) web link (www.youtube.com) (TXT) w3m dump (www.youtube.com) | Steltek wrote: | I feel like there was an indirect experiment here: how quickly | defenseless humans can be mauled by a struggling cat in an | enclosed space. | bagels wrote: | Humans can reason about the physics, might have an advantage of | efficient escape. | balls187 wrote: | Footage here: https://www.youtube.com/watch?v=okZW3_5Gr4s | tyingq wrote: | These parabolic flights give you ~25 seconds of a close to zero-g | environment, but bookended by some pretty uncomfortable ~+-2g | before and after periods. It would be interesting to see the cats | in a more stable and extended zero-g environment to see how they | adapt over time. | pwdisswordfish9 wrote: | A buttered piece of bread would be cheaper | Simplicitas wrote: | In a priori, isn't this kinda obvious ... LMAO | xwdv wrote: | I'm not sure what they expected? Which way is a cat supposed to | auto-right to in a weightless environment? | teraflop wrote: | But a cat free-falling from a height is also weightless, and | yet they manage to right themselves using perceptual cues. The | point of the experiment is to see how the _behavior_ changes | when the sensation of weightlessness is presented for an | extended period of time, without the "falling" motion | (relative to the perceived local environment) that normally | accompanies it. | ars wrote: | This is what most of the people replying here are missing - | all falls are "free fall" (zero g). | | Yes the cat manages, but not in this situation. | NovemberWhiskey wrote: | The cat's system has memory. The transition into free-fall | from a state where it was previously experiencing ground | reaction force provides a cue for the self-righting reflex | on the direction of "up/down". Apparently even blind cats | can self-right based on their vestibular system. | moron4hire wrote: | Any fall is a weightless environment, whether it's in a plane | or off a building. | | But in a plane, you don't have the air rushing past your | whiskers. | jstanley wrote: | The cat might use visual cues to right itself. | | It might have been interesting to re-run the test with a more | obvious "horizon" and see if the cats react to that. Then if | the cat still doesn't right itself, it seems like it is using | acceleration rather than vision to determine which way is down. | nealabq wrote: | Do we know it's visual? If you drop a cat in darkness (onto a | pillow of course), will it right itself? What if you put it | in an elevator that accelerated downwards at 1G so the cat | fell to the ceiling? How does it know which way is down? Is | it the horizon, or the bright sky, or does the cat remember | the scene before it was dropped? Or is it the air rushing by? | cecilpl2 wrote: | > Then if the cat still doesn't right itself, it seems like | it is using acceleration rather than vision to determine | which way is down. | | This is not possible because objects (including cats) in | freefall do not experience the sensation of acceleration. | smaudet wrote: | true_religion wrote: | Before a cat (or any object) experiences free fall, they | experience acceleration so they know which way gravity is | pulling them. Surely, a cat can remember what happened to | it in the last few seconds and instinctually put its feet | in that direction? | throwawayben wrote: | You don't feel any acceleration from gravity - it can | only be determined from other senses like vision or the | air flowing over your skin/fur | haneul wrote: | This is possible because in free fall on earth, there are | directionality signals when blinded - for example, air | resistance. | ce4 wrote: | Probably the same reason as discussed here recently: A naked | skydive inspired a way to keep pilots oriented in flight | (military.com) https://news.ycombinator.com/item?id=30959126 | | Edit: Probably that submission led to this one. | carabiner wrote: | At the 28 sec mark, in the upper right one of the cats appears to | be walking on the ceiling. | technick wrote: | Buttered Cat Paradox | | https://en.wikipedia.org/wiki/Buttered_cat_paradox | digitalsanctum wrote: | You had me at "cats in zero-g" | xallarap wrote: | gene-h wrote: | the cat righting maneuver is a zero-angular momentum maneuver, so | if the cat has a slight amount of spin, it is not possible for | the cat to correct it. That may be what happens in the video | eterevsky wrote: | Can a cat barf from disorientation? | progre wrote: | Yes. | | Source: Have traveled with carsick cat. | rossdavidh wrote: | We know humans in zero-g often barf a lot, and cats often barf | a lot, so it seems like cats in zero-g was a high-risk | experiment. | pdonis wrote: | In zero-g there is no such thing as "landing on your feet" | because there is no such thing as "landing". There is no "down" | direction so of course cats can't detect something that doesn't | exist. | lgessler wrote: | That's certainly the intuition most people would have about | this, but it's still interesting to see it borne out when in | principle there could have been other, surprising signals that | cats respond to in order to right themselves. | pdonis wrote: | _> That 's certainly the intuition most people would have | about this_ | | Actually, though, it's wrong. See my responses to others | elsewhere in this thread. | sophacles wrote: | I'm pretty sure the enemy gate is down. | throwawayben wrote: | zero-g is the same as falling though, just with no apparent | acceleration. | nemothekid wrote: | I've never thought critically about this - but in free-fall | on earth, you are falling through the air which could be used | to measure the direction of the fall. | ndr wrote: | Is it? What about the resistance of air that was not going at | your own speed? | dfxm12 wrote: | Acceleration is a vector. A vector is magnitude and | direction. "Down" is a direction. If there's no acceleration, | there's no "down". That there is no acceleration in "zero g" | is a critical difference between "falling" and "zero g" in | this context. Therefore, they aren't the same. | pdonis wrote: | _> Acceleration is a vector._ | | True, but _which_ kind of acceleration are we talking | about? | | A cat in the "zero g" in the experiment described in the | video has no _coordinate_ acceleration relative to the | Earth. Whereas a cat falling off a ledge to the floor does | have coordinate acceleration relative to the Earth. | | But _both_ cats have zero _proper_ acceleration--they are | both weightless. (Air resistance will become significant at | some point during a fall from a height to the floor, but | cats are heavy enough that I don 't think that would be | significant in most falls where cats are observed to land | on their feet.) And "zero g" means zero _proper_ | acceleration, not zero coordinate acceleration. So the GP | is correct and my original comment was in error: cats in | both situations are in "zero g" so that can't be what is | causing the different behavior in the two situations. | Rygian wrote: | If there's no rushing wind tingling your hairs, then it's not | the same. | sdeframond wrote: | Next : dropping a cat in 0g _in a wind tunnel_ | mrexroad wrote: | I think most people would consider "falling" to be going | "down" a gravity well. Stable orbits around a gravity well, | or at sufficient distance to not be influenced by it, are not | what most would consider to be "falling." | jameshart wrote: | But that's a misunderstanding. Stable orbits _are_ free | fall. | | There is no such thing as a stable orbit "at sufficient | distance to not be influenced by" gravity. | | There's no such thing as a sufficient distance. | e_y_ wrote: | I think more precisely, the traditional definition of an | orbit (stable or not) is that it's influenced by gravity. | You could be in a situation where the influence of | gravity was negligible (say, far beyond any galaxy) but | it wouldn't be considered an orbit at that point. | | I guess certain multi-body situations like Lagrange | points might make it debatable about which "direction" | you're falling though. | pdonis wrote: | In the sense that matters for this discussion, zero g _is_ | the same as falling--both are weightless conditions. So the | GP is correct and my original comment was in error; "zero | g" can't be what is making the difference. | tomxor wrote: | Pretty sure this was a low effort excuse to play with cats in | zero-g... and who could refuse :D | lisper wrote: | The problem with that theory is that while a cat is falling it | is in zero G. | | It actually makes an interesting puzzle to figure out what a | cat is actually responding to when it lands on its feet after a | fall. | MarkMarine wrote: | The cat is being accelerated at 9.8m/s2 towards the earth | while falling. What do you mean by this? | MrPatan wrote: | Isn't the cat also being accelerated at 9.8m/s2 towards the | earth while in "zero g"? | metrognome wrote: | While falling, the cat is in an inertial reference frame, | so it is not accelerating. The ground is actually | accelerating upward at 9.8 m/s2, counteracting the flow | of spacetime. | | This Veritasium video gives an intuitive explanation: | https://youtu.be/XRr1kaXKBsU | pdonis wrote: | _> The problem with that theory is that while a cat is | falling it is in zero G._ | | Ah, yes, I see your point. Air resistance would eventually | kick in and provide positive G, but not in a short enough | fall. And cats are heavy enough that "a short enough fall" | probably includes most falls in which they are observed to | land on their feet. | btilly wrote: | I'm sure that it keeps track of which direction is up with | the same inner ear mechanism that we use for our balance. | Given that it starts properly oriented thanks to gravity, and | doesn't spend long falling, this gives it a good idea which | direction is up when it lands. | | Spend long enough out of gravity, and it will get confused. | As do we. | JumpCrisscross wrote: | Could also be the sensation of air rushing past [1]. | Curious to test the competing hypotheses--dead reckoning | from initial alignment versus air movement--in a wind | tunnel. | | [1] https://www.military.com/history/how-naked-skydive- | inspired-... | pdonis wrote: | Yes, this makes sense. | [deleted] | sandworm101 wrote: | Whiskers. Every cat is perfectly aware of the rapidly | accelerating wind rushing past its head. Them they have ears | to hear that wind. Lastly they have eyes and some experience | with life on solid ground. They see it coming and understand | what that means... Unlike sperm whales. | screye wrote: | That is only true in a vacuum though. The cat is feeling the | air resistance locally on the parts that face forward while G | is applied uniformly. | lisper wrote: | That's one possibility but I'm pretty sure that's not it. | If it were, then if you dropped a cat in a stiff breeze it | would land sideways. | bhedgeoser wrote: | Do they? | tailspin2019 wrote: | There's only one way to find out... | throwanem wrote: | I'll bring the cat if you'll bring the wind tunnel! | mrtweetyhack wrote: | JumpCrisscross wrote: | SmarterEveryDay did a great video series exploring cats' self- | righting mechanisms [1]. | | [1] https://www.youtube.com/watch?v=RtWbpyjJqrU | Melatonic wrote: | We probably should keep cats out of space - can't have them | spontaneously evolving into Kzinti or something :-D | daneel_w wrote: | Since the ability depends on motion sensing, is this really | surprising to anyone? In other news, kettlebells lose their | "heavy" in zero G. | daveloyall wrote: | Off topic: Kettlebells might lose their "heavy" in micro- | gravity[1], but they don't lose their "massy". I first read the | term "massy" in some sci-fi book, by Heinlein, I believe. | | It takes more effort to overcome the inertia of an object with | a lot of mass than it does to overcome the inertia of an object | with less mass. So, you can still use massy objects to work out | in micro-gravity! Or so I've been led to believe by convincing | fiction. :) | | 1: I've also been led to believe that micro-gravity is a better | term than zero-g for the conditions experienced during free | fall. | unfocussed_mike wrote: | Dear scientists, for the love of all that is good, don't repeat | this test. | | Cats aren't ever going to forgive you for engineering a situation | where they are seen to land in an ungraceful way, and there's a | tiny chance that they will make us all pay when they evolve | opposable thumbs. | frederikvs wrote: | Cats can't be bothered to evolve opposable thumbs. They have | human staff to take care of anything that requires an opposable | thumb, why would they bother doing it themselves? | cpsns wrote: | I have 3 cats with "thumbs". Believe me they're working on | evolving them. | tenebrisalietum wrote: | Cats are crafty enough to both survive and plan for a post- | human landscape, such as climate change, World War III, or | supply chain issues driving up cat food prices. | progre wrote: | What? To me it looks like they _try_ to turn their bodies but in | freefall they can 't make sense of where down is. No reflexes | lost. | ordu wrote: | Yeah, those guys kept kicking or pushing cats preventing them | to orient themselves. Cats were surprised by the lack of | gravity, but they were not given a chance to adapt to new | circumstances. | itslennysfault wrote: | I was thinking the same thing. They're still rotating the way | they normally would. Toward the end of the video the orange cat | floats "up" from the floor toward the ceiling and turns it self | around to "land" on the ceiling feet first. | hosh wrote: | Poor cats. It looks like they are completely outside the | parameters of their instinctual movements. | arwhatever wrote: | Am not surprised that zero G severely disorients them, already | knowing how a much a simple piece of tape disorients them. :-) | | https://youtu.be/mdBegLNE6OU | KarlKemp wrote: | This is the sort of experiment the biologists I know come up with | towards the end of a long night. | engineer_22 wrote: | ->Cats in zero-g lose their auto-righting reflex | | Same for humans. | alex_young wrote: | What was the zero-g cat dropkick at the end about? Seems pretty | unethical. https://youtu.be/O9XtK6R1QAk?t=29 | syllospri wrote: | That's not what a dropkick is. In a similar way to someone else | pushed a cat, the man used his foot to move the cat away from | the floor, but because of the zero-g, it caused the cat to move | to the ceiling. Hardly unethical. | kazinator wrote: | When a cat is in free fall, that _is_ weightlessness. At least | initially, until air resistance starts limiting the velocity. | | In zero-g, you do not directly sense in which way gravity is | pointing. | | Probably, under the conventional free fall situation, the cat is | relying on visual clues, and the sensation of air moving through | its fur, to establish which way it is falling, as the basis for | the righting reflex: which way to aim the paws. Those clues are | absent in the simulated zero-g environment, which feels like free | fall, but the cat doesn't see any relative movement to anything, | or feel any air movement. | floxy wrote: | >the cat is relying on visual clues | | That should be pretty easy to test. Anyone know if blind cats | land on their feet? If blind cats are in general too geriatric | to test on, what about a blind fold, and dropping your cat | upside-down on a bed? | aidenn0 wrote: | So maybe repeat the experiment, but with a giant fan? | geenew wrote: | Could you accomplish the same thing in a ground based lab | with a fan blowing air up at ~80 degrees? If airflow is used | for orientation, then the test subject should orient to be | parallel to the direction of airflow as it is falling. | | All for Science, of course. | | (The 80 degrees thing is there so they don't hurt themselves | when they reach the ground - hopefully being only 10 degrees | off vertical will be recoverable). | someweirdperson wrote: | Don't forget to shave the cats before conducting the | experiment. | kazinator wrote: | Then, separately, experiment with LCD or projector screens | simulating motion, and then the two in combination. | | (Remembering to reset the cats to initial values of the | feline parameters before each attempt, or else using freshly | allocated cats.) | PaulHoule wrote: | I'd like to take a cat to a space station like they did in some | Heinlein books. | | One would think they'd learn to deal with weightlessness better | if they had a few weeks to get used to it rather than a few | minutes on a plane. | | Don't know what you'd do for the litter box though. | MisterTea wrote: | > Don't know what you'd do for the litter box though. | | dear god... the image of a regular litter box in zero G made me | wince. I had a cat years ago who was an excavator and make a | big mess whenever she went on archeological digs. | | Another thought, cats typically bolt from the litter box after | pooping (one guy I have does an amazing 90 degree wall kick- | walk ninja move to run downstairs.) Not happening in 0G :-) | pkdpic wrote: | > Don't know what you'd do for the litter box though. | | pray | PaulHoule wrote: | I thought about picking up the turds with gloves, wondered | what I'd do about the urine, or what I'd do if the stools | were loose and then I thought "are cat diapers a thing?" and | it is available COTS | | https://barkertime.com/designer-cat-diapers/ | Buttons840 wrote: | Has an animal without "grabbing appendages" ever been in space? | What did it do? | Symmetry wrote: | Tadpoles have been: | | https://www.newscientist.com/article/mg14519690-700-space- | fr... | leshow wrote: | Yep, from fruit flies, dogs, mice to fish: | https://en.wikipedia.org/wiki/Animals_in_space | jxy wrote: | You can probably put a few mice in a centrifuge of 1 meter and | they would be happy. Make the centrifuge 10 times larger, we | can fit a litter box. | gnu8 wrote: | This sounds like a worthy experiment. Why don't we already | have a mouse artificial gravity habitat on the ISS? | cecilpl2 wrote: | > Don't know what you'd do for the litter box though. | | Cat diaper? | Jaruzel wrote: | However, Heinlein cats also walk through walls - not good when | space is on the other side. | qbasic_forever wrote: | Judging by how my cat can disappear and reappear at will all | around my place... I wonder if household cats already have | that ability. | jimmygrapes wrote: | Pixel walks through walls because nobody explained that it | can't be done, so I imagine the same would apply for | breathing in and staying pressurized in a vacuum | rdl wrote: | My plan is to go to Mars with the first domestic pet cat; it | implies a level of civilization/comfort/safety (to be able to | have pets) which is consistent with what I'd want myself. Maybe | 10k people? 50k? Hopefully I live that long. | roywiggins wrote: | Shackleton's ill-fated antarctic expedition had a cat, so | maybe not as much of a guarantee as you'd think... | | https://en.wikipedia.org/wiki/Mrs_Chippy?wprov=sfla1 | PaulHoule wrote: | Ocean ships have rats so they would tend to have cats even | if people didn't encourage them. | | With the COTS technology of cat diapers I think they could | have a pet cat on the ISS but they don't want the risk that | it goes wrong and they'd have to put it down. | rtkwe wrote: | There's also the smell, by all accounts the ISS already | smells a little bad from decades of BO and grime, I would | not want to add the smell of cat shit to that. | jarofgreen wrote: | And loving pet owners will want to note it did not end well | for the cat | qbasic_forever wrote: | Every major sea voyage of the past had a cat or two, they | were necessary to keep rats from eating all the food | supplies. | | Apparently the cat on board the expedition that discovered | New Zealand immediately upon reaching land jumped out and | grabbed a small flightless bird (then a brand new species | discovery) and dragged it on board to eat. | aspenmayer wrote: | Cats have been a menace to the native kiwi birds ever | since. | qbasic_forever wrote: | Cats can be trained to sit on and use a human toilet seat. A | space toilet with a vacuum would be more challenging but I bet | a dedicated animal behaviorist with enough time and training | could get a cat used to using a space toilet. | nicwolff wrote: | Not if it sounds anything like a terrestrial vacuum cleaner - | cats do _not_ get used to those. | FlyMoreRockets wrote: | It may just be easier to design a zero G litter box. A screen | bottom with a coarse granular material and sufficient airflow | through the bed could work. No idea how a cat would dig in | zero G though. | throwanem wrote: | Sturdy screening to give claws a grip would probably serve | as the equivalent of human handholds just generally. I | don't know how comfortable or feasible walking on it would | be, but I bet a cat could learn pretty quick to catch on to | it and then push off along a desired vector, and they're | already better at gyroscopic pointing than we are. | robbedpeter wrote: | Diapers, maybe, or the litter / pan would have to be under a | constant slight suction? A big enough hamster wheel to give the | cat gravity? | | Someone's gonna have to answer this question in the next decade | when rich space tourists want to bring their pets. | | Heck, a space cat live stream could probably fund a significant | part of a new station. | emerged wrote: | It wouldn't be a super ethical test.. but I wonder if a cat would | adapt and start doing some really crazy ninja moves all over the | place, if you left him in zero-g for a few years. | Epiphany21 wrote: | Unethical? Have you seen the inside of the ISS? It's cat heaven | with all the cables and stuff hanging around, and nothing is | too high to jump on when you're almost weightless :) | secondaryacct wrote: | You misunderstand cat adaptation !!! These little bastards | would learn to swim lazily before spending any effort on ninja | moves :D Have you seen a well-fed pampered cat, the thing will | meow for his food before even turning his head towards its | human slave. | | Those auto righting reflexes are just there to ensure their | eternal survival when presented to (rarer and rarer) danger. | | They're Gods making us do their bidding while they pretend | we're the masters :D | hjek wrote: | This is animal abuse! | madacol wrote: | http://paulgraham.com/heresy.html | c22 wrote: | Do cats in zero-g fall? | glouwbug wrote: | Considering cats fall feet first and buttered toast butter side | down you can power your spaceship by taping buttered toast to | your cat's back and attaching the cat toast contraption to the | rotor of a generator | FabHK wrote: | That experiment has been performed and indeed produces | surplus energy, according to reliable sources :-) | | https://www.youtube.com/watch?v=Z8yW5cyXXRc | Rebelgecko wrote: | I think this post is using a technically-wrong-but-still-more- | or-less-gets-the-point-across definition of "zero-g" | yupper32 wrote: | It's relative. | ISL wrote: | To a reasonable approximation, cats only fall in zero-g. | draw_down wrote: ___________________________________________________________________ (page generated 2022-04-11 23:00 UTC)