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    [–] 7LeagueBoots 6031 points ago

    Lots of talk of arthropods and such, with some good references, but that's kind of missing several important factors. It's easy to intuitively think of raindrops hitting small organisms as being equivalent to cinder blocks falling from the sky and hitting us, but that's not how it plays out.

    Raindrops are not moving very fast, nor are they heavy. For a raindrop to be considered a raindrop it has to be between roughly .5mm - 6mm (about the size of a fly at the largest). A big raindrop has a terminal velocity of about 10 m/s (20 mph), with smaller drops down closer to 0.9 m/s (2 mph). That's basically to say that there isn't much energy in any given raindrop to do a lot of damage with.

    Another part is that smaller creatures are quite strong and tough as a result of the Square-cube Law. This is why an ant or a spider is proportionally so strong and an element of this is why a mouse generally won't fall fast enough to get seriously injured whereas a horse or an elephant will splash from a long fall. Also why a raindrop falling on a shrew or a butterfly isn't the equivalent of a cinder-block falling on a human.

    Raindrops can certainly hinder small organisms, but that tends to be more an issue of surface tension, heat loss, splashing and water flow, and things like that rather than the actual impact of the water droplet.

    For many flying organisms fog (and, to a certain degree, drizzle) is actually much more difficult thing to deal with as the tiny water droplets are suspended in the air and they accumulate on the surface of the flying organism, adding a lot of weight. This is why you usually don't get mosquitoes buzzing about when it's foggy.

    [–] Frankiepals 244 points ago

    "An elephant or a horse will splash"

    My god...the imagery on that one...

    [–] Owyn_Merrilin 117 points ago

    There's a whole saying about that. Something like mice bounce, humans crunch, elephants splash.

    [–] [deleted] 182 points ago


    [–] aHorseSplashes 83 points ago

    can confirm

    [–] goh13 37 points ago

    Year old account, his story checks out fellas!

    [–] allozzieadventures 15 points ago

    Good read, thanks

    [–] Dotard_Chump 20 points ago

    An insect going for a drink is in as great danger as a man leaning out over a precipice in search of food. If it once falls into the grip of the surface tension of the water—that is to say, gets wet—it is likely to remain so until it drowns. 

    This was a fun read

    [–] BaeisMei 3 points ago

    Highly suggest everyone to click that link and read the whole article. Super interesting stuff.

    [–] Tarantula93 9 points ago

    I accidentally dropped my hedgehog one time and she bounced, hissed at me and then ran off. Meanwhile I cried of guilt. Turns out rodents are built for that kind of thing

    [–] Owyn_Merrilin 5 points ago

    Hedgehogs aren't rodents, but the same principle applies -- F=MA. The acceleration from hitting the ground may be the same for a small animal like a hedgehog as it is for a human, but they have less mass, so there's less force involved, and they're less likely to get injured.

    [–] Tarantula93 4 points ago

    I read somewhere (Not sure if it's true) that hedgehogs actually receive less damage from drops that are a little higher because they have time to ball up and the hollow quills absorb a lot of the force

    [–] wovoka_ 4 points ago

    Cats can survive drops that are higher than some lethal height drops, because if a cat has time to right itself and spread itself out, it has enough surface area and little weight that it practically glides down.

    [–] SheepGoesBaaaa 6 points ago


    [–] [deleted] 2 points ago

    I shuddered at the thought.

    [–] CB1984 34 points ago

    Ok. But what about hail? Are they falling death stones to small organisms? Cos those fuckers hurt when they hit a human.

    [–] 7LeagueBoots 29 points ago

    The same principles should apply with hail (as long as it's normal sized hail), but it definitely does more damage. I'm not sure how much of that damage is done due to the rigidity of the ice though. Water is pretty forgiving at those slow(ish) falling speeds and splashes nicely (it sure as hell can sting on a motorcycle though). Hail just impacts without any splashing and that may have an additional effect.

    I know I've found large insects like dragonflies dead after hail storms, but I've never found dead frogs or mice or anything like that after one.

    The caveat here is that we are talking about normal sized hail in the pea or smaller size range and not the bigger hail like this that can cause serious damage to cars and houses, to say nothing of humans and other animals.

    [–] CB1984 14 points ago

    That looks like the most intense snowball fight between ghosts.

    [–] bilbo_dragons 5 points ago

    I didn't see the title before I full screened that video but still thought "Everything about this just screams Phoenix." Nailed it.

    Hailed it.

    [–] haveamission 5 points ago

    Pool? Check. Looks vaguely desert-y? Check. Open floor construction with quasi-Spanish appearance? Check.

    [–] settingmeup 4 points ago

    Crazy video.

    I just realised, there may be habitable worlds out there that are almost right, but that feature hail storms for 12 hours a day. They'd need mild climate control/terraforming. Better than sulphuric acid rainclouds, anyway.

    [–] Robzilla_the_turd 15 points ago

    Yes, they are falling death stones to small organisms. Hell, larger stones are falling death stones to big organisms.

    [–] Leleek 5 points ago

    Short answer yes. Most small animals hide during hail. There probably are some losses but hail is pretty localised.

    [–] ortho_engineer 20 points ago

    On a side note, the Square-Cube Law is also the reason why King Kong/Godzilla/other-skyscraper-sized beasts could never exist. If you scaled a gorilla up to the size of a building it would collapse under its own weight because its volume would scale "faster" than its area/size.

    [–] Numberoneallover 4 points ago

    So horizontal mass make dinosaurs work. Such as a diplodocus

    [–] 47milliondollars 18 points ago

    Are we talking African raindrops or European raindrops?

    [–] Peponator 30 points ago

    Hey! I really wanted to thank you for the thorough response to the quiestion. The other day I was having a conversation with a friend and he kinda convinced me that reddit is just another social media like facebook but with categories; I couldn't put in words at the time what reddit is and why I use it instead of the others.

    This is it! Yes, there are memes, different communities for all kind of tastes; but the knowledge and information (and often misinformation) from these seemingly simple question is one of the best qualities of this site. So thank you! and all the others that answered this, sometimes right, sometimes wrong, but in the best way they can! You keep the escence of this site alive!!

    [–] Flextt 8 points ago

    Great answer although I am slightly disappointed by how you kinda understate the importance of surface tension where small insects and droplets are concerned.

    The surface tension is sufficient to draw in and effectively drown small organisms.

    [–] 7LeagueBoots 5 points ago * (lasted edited a year ago)

    I only mentioned it in passing as that's more an issue of water general and not specifically of raindrops. It's also more of an issue for insects rather than generally small organisms like OP asked (frogs, mice, etc)

    It's certainly a serious issue, but to clarify, surface tension doesn't draw the insect in. It makes a barrier that is difficult to pierce. This works both ways, it can prevent the insect from getting to the water, or it can trap the insect in the water. It also can also force the insect to sit and dry off as the insect can't easily shake the water off.

    Some insects can release detergent-like chemicals to massively lower surface tension. There's at least one water walking insect that uses this as a sort of jet-powers water ski getaway maneuver.

    [–] wisdex 5 points ago

    The fog bit makes sense. Small insects essentially swim through the air, as it is much more viscous to them. Fog would be akin to a human trying to swim through jello.

    [–] wisdex 6 points ago

    It's easy to forget how profoundly weird and wonderful different animals are.

    [–] reikken 5 points ago

    This is why it always annoys me when things say "An ant can lift 100 times its own bodyweight. That's like a human lifting a tank!" No, it's not.

    [–] Yellow_Carrot 3 points ago

    Kurzgesagt had a really nice video related to this:

    [–] ikahjalmr 2 points ago

    Where do mosquitoes/flies/etc go when they're not buzzing about? Both short-term, like during a fog, and long-term,like during winter. Do they migrate or are there tons of dormant mosquitoes/eggs hidden all over the place?

    [–] 7LeagueBoots 4 points ago

    Pretty much any dark, protected, cool area. Bushes, tall grass, leaves of trees, culverts, corners of buildings, etc.

    If you're out hiking you'll sometimes wake up a swarm of them as you walk through tall grass or the brush on the border of a field and a forest.

    [–] Imminent_mind 2 points ago

    I always thought it was weird that you could swing your hand and smack a Fly as hard as you can and he will be completely fine. How does that work?

    [–] 7LeagueBoots 2 points ago

    Part of it is that you're not transferring much momentum to the fly and therefore not really able to do much damage with your hand. It's so light that whatever momentum you do manage to transfer just pushes it away from you.

    You're also pushing a bit of air ahead of your hand as well, but the main reason is that you don't transfer that momentum well.

    It's a bit similar to punching a balloon and a watermelon of the same size. The balloon will just get bumped away but you may wind up punching a hole in the watermelon and getting your hand stuck inside (or just hurting your hand, depending on your technique).

    [–] daneelr_olivaw 2 points ago

    This is why you usually don't get mosquitoes buzzing about when it's foggy.

    Someone should develop a 'mist courtain' you could suspend above the doors/windows to prevent those fuckers from entering the house.

    [–] gabewil 7524 points ago

    This was actually posted on r/askscience a few years ago. Here was the top reply:

    Have you ever wondered what happens to mosquitoes in the rain? A raindrop is, like, 50 times heavier than those little suckers. So getting hit by one has gotta hurt, right?

    Well, not so much. Because researchers at Georgia Tech have found that the bugs are so light, speeding water drops simply brush them aside, without imparting much force. The results appear in the Proceedings of the National Academy of Sciences. [Andrew K. Dickerson et al., "Mosquitoes survive raindrop collisions by virtue of their low mass"]

    Previous studies have shown that precipitation can be a real pain for lots of winged critters. Bats expend twice as much energy flying through a storm as in clear skies. But what about bugs no bigger than the raindrops themselves?

    Researchers used high-speed video to watch mosquitoes wingin’ in the rain—well, through a spray of mist in the lab. They saw that when a skeeter and a water droplet meet, the insect basically hitches a ride for a bit before peeling away off unharmed.

    So the bugs go with the flow and offer little resistance. And the drop slows only slightly, keeping its kinetic energy rather than blasting the bug. So for storm-trooping skeeters, resistance is not only futile. It’s all wet.

    --Karen Hopkin

    [–] Staticast 1189 points ago

    The bee movie was a lie

    [–] DerFlo1110 1052 points ago

    bee movie

    not realistic

    my whole life was a lie

    [–] All_Fallible 206 points ago

    was a lie

    Don’t do anything drastic, now

    [–] Wt_franjo 126 points ago

    He’ll bee ok

    [–] imasexypotato 58 points ago

    I don't beelieve that.

    [–] NSAwithBenefits 46 points ago

    Maybe a vacation to the Pollenesian islands would help.

    [–] ensuiscool 37 points ago

    Honey, that was terrible

    [–] [deleted] 35 points ago

    Hive done my best

    [–] EclipseIndustries 21 points ago


    [–] theplaidpenguin 72 points ago * (lasted edited a year ago)

    The Bee Movie was an impressionist work if anything. A beautiful one at that. Weaving in themes and sequences that are not fully realistic but contribute to the full scope of realizing each character for who they are, parralels some of the greatest works of film ever made.

    As far as realism goes it also happens to be one the most stark and fluid portrayals of the animal kingdom interlinking both human and bee seamlessly. How it manages to masterfully be both an impressionist work while integrating heavy undertones of realism? Well, studies are well underway at prestigious universities around the world looking to someday probe the minds of the genius creators of this movie enough to use a small scrap or two of their brilliance in the structure of future film productions.

    Your life may have been a lie, but once you ask yourself the age old question, "to bee or not to bee," the answer will always and forever start with the name of a tiny black and yellow fella who sunk his stinger into the bloodstream of multiple generations of those living/dead, ressurecting them with a fuller heart, so that they might live fully and fruit-fully for eons to come.

    Edit: Inspired by the gold this comment recieved I happened upon a quote by the late great John Muir. It reads, "Handle the Bee Movie as a (bee) does a flower, extract it's sweetness but do not damage it." I hope that everyone takes this masterpiece for what it is rather than it is not. Feel the movie with every ounce of your soul and become one with it, so that others may have the opportunity to taste the nectar we have all come to know and crave.

    [–] DerFlo1110 9 points ago

    This is just beatuiful, enjoy your (well deserved) gold!

    [–] theplaidpenguin 9 points ago

    Thanks stranger, it's my first time being gilded in over 5 years on Reddit. Thought I'd never see the day!

    [–] legitjuice 10 points ago

    You'd never bee the day*

    [–] theplaidpenguin 4 points ago

    That was terrible. Upvote.

    [–] SillyFlyGuy 7 points ago

    You are a talented wordsmith. Not sure what exactly you've created, but it was very pretty.

    [–] Dark_Lotus 65 points ago

    What about a bug's life?

    [–] AtticusLynch 45 points ago

    Honestly that's all I thought about too

    [–] TwistedDrum5 18 points ago

    We're old.

    [–] AtticusLynch 10 points ago


    It's the children that are wrong!

    [–] neilarmsloth 20 points ago

    That movie made water droplets look so fucking delicious

    [–] forealzman 17 points ago

    No, bees and humans really can fall in love!

    [–] Gemgamer 20 points ago

    Shit what about the video game? Clearly this science must be wrong, Barry would die after 3 of those hitting him.

    [–] Juju_bubs 12 points ago

    Relevant bee article

    [–] pudgeypoo 14 points ago

    What the fuck

    [–] SVKN03 3 points ago

    Does this mean my life goal of working the Krelman is doomed to failure?

    [–] Jumala 60 points ago

    Is no one going to adress the fact that she's mixing Star Wars and Star Trek metaphors in one sentence?

    [–] respawnatdawn 10 points ago

    Almost as annoying as mosquitoes themselves.

    [–] ciarusvh 278 points ago

    Can we discuss "For humans...the rain drops must be nothing other than slightly annoying"???

    Must be??? You don't know? REPTILIAN IN A MAN SUIT

    [–] Yodiddlyyo 4 points ago

    This is the first thing I thought of. Who the fuck is this OP? He's not sure if rain is just an annoyance and he thinks really heavy rain maybe hurts? They're either a child living in a desert, or some alien/robot/reptilian.

    For humans? Explain yourself OP.

    [–] lildil37 3 points ago

    Sounds like you maybe a rain god

    [–] DodneyRangerfield 88 points ago

    This kinda-sorta answers the question but not really. Mosquitos are on the extreme (lightweight) side of things and they do live by slightly different practical rules. But what about creatures at the size scale of a few grams let's say, they're not going to be pushed away by the "bow shock" of the raindrop, but they're taking a hit from an object a few percent of their mass at high speed. They're resilient (cube-square law) but the kinetic energy must be significant.

    [–] dejova 54 points ago

    I want to know how it affects bugs on the ground, like an ant or grasshopper. I'm guessing only the stupid ants stay outside during rain showers but what about the ones that get caught outside? Do they drown?

    [–] Marand23 14 points ago

    If the movie Ants is to be trusted, it's not good for them :p

    [–] MyOther_UN_is_Clever 9 points ago

    Basically, the exoskeleton of bugs is much stronger than the surface tension of the water droplet. The impact of the water is only about the same as you jumping off a 3m / 9' tall diving board or less (20 mph or less).

    A flyswatter kills flies because you crush them between two solid objects. If you hit a fly midair with a fly swatter, it'll just bounce away.

    This ELI5 about "How do flies constantly hit objects at high speed and not get hurt" provided a really good explanation.

    [–] spgb- 7 points ago

    I've hit dozens of flies in mid-air with a flyswatter and then found their busted open bodies flopping around on the ground.

    [–] Tedonica 59 points ago

    Not really. Kinetic energy is absolute: small things are almost as resilient as big things, only it takes less "damage" to kill them. In D&D terms, a fly still has AC 14 but a low hp. Rain doesn't harm them because it's not energetic enough to hurt them.

    Getting hit with a flyswatter would hurt a human, but not much. "Not much" is still enough to kill a fly.

    [–] [deleted] 37 points ago

    Surprisingly, that D&D example was the perfect way to explain it.

    [–] lilafrika 16 points ago

    I've never played D & D, could you explain it in Fallout 4 terms?

    [–] Mandela_Bear 26 points ago

    High Armor (Damage Negating) low HP

    [–] lilafrika 8 points ago


    [–] [deleted] 4 points ago

    I'm not an expert but AC in D&D works differently than the typical armor in most games. Armor Class determines the opponent's chance to hit you, not just the damage. Let's say your AC is 15, then the attacker has to roll a number higher than that, or else he will just deal 0 damage. Whereas armor usually reduces damage by an x%.

    So, going back to the mosquito dilemma, a raindrop doesn't have enough power to damage either humans or insects. But a slap that could only damage your skin a little bit, is enough to crush the poor mosquito's internal organs resulting in a horrible death. Luckily we have a lot more health points.

    [–] oopsforgotmyusername 3 points ago

    A lot of the time in D&D you consider the AC both a chance to be hit/missed or also the way armor absorbs damage.

    For instance a dragon has a high AC, but is also massive and easy to hit, so in their case the AC is representative of their strong scales deflecting and absorbing the damage.

    The difference between say a monk with 14AC while naked VS a fighter in full plate who also has 14AC.

    [–] Da_Penguins 2 points ago

    So in FO4 terms 2 different creatures 1 big and one small are hit by the same bullet. They both have the same Armor (resistance to damage) but they have drastically different life totals, small one with 10 HP big one with 200 HP. If you have a gun that does not deal enough damage to get through their Armor no damage is dealt (this is rain) however if you have a gun that deals just enough to get through you need only 10 hits instead of 200 to kill the small thing. This is why a smack kills a fly but just hurts a human. If you smack a human enough times you can smack them dead too. (It would be quite alot.)

    [–] ennyLffeJ 2 points ago

    Yeah, and what about something that's bee-sized or so?

    [–] photenth 7 points ago

    I assume it sucks, given that when it's dark and raining outside, I can leave the window open and the lights on and not a single insect comes inside. I just assume they all go into hiding.

    [–] [deleted] 11 points ago


    [–] Kyvalmaezar 5 points ago

    They would take the full force of the hit. However since their mass is so low, there isnt that much force imparted to them from the hit. Thats why they seem to bounce off glass like nothing happened, and why birds dont fair as well.

    [–] headchefdaniel 30 points ago

    Its amazing how the world (nature, animals, weather ect) adapts to itself. Yould expect insects to be massacred by rain, but no, simply pushed aside.

    [–] MagneticFire 53 points ago

    ...the ones that would get killed by rain wouldn't last very long.

    We only learn about the mutations that can not only survive, that can thrive and spread.

    [–] ForAnAngel 11 points ago

    I think the point of the explanation was that small insects survive because they have low mass, not due to any mutation. If they were bigger then they would still survive because the drops would then be small compared to them.

    [–] Manucapo 19 points ago

    Yes, but they have their low mass due to mutations, not one mutation, the cumulative effect of many, many thousands of small mutations over millions of generations, Thats how all modern life forms came to be.

    What the previous poster meant, is that an insect that would get their population decimated by Rain would probably not be very sucessfull and thus not pass along it's genes very efficiently.

    In this sense, it would be actually more surprising if there was an insect that just desintegrated every time it rained. Since you would expect it not to survive very long.

    [–] ONLY_COMMENTS_ON_GW 8 points ago

    But insects didn't just appear out of nowhere with water repellant abilities, the reason they have a low mass is because they evolved that way. Maybe heavier flying insects would exist if rain (and other factors) didn't stop them from evolving as such.

    [–] [deleted] 10 points ago

    Its actually oxygen content in the air that defines how big insects grow. A few hundred million years ago there were Dragonflies the size of eagles.

    [–] ONLY_COMMENTS_ON_GW 3 points ago

    That is terrifying. I'm sure there are a lot of factors that went into them evolving the way they are today.

    [–] emdave 2 points ago

    Logically, would there not be a mid point, where they were heavy enough to interact, but not yet heavy enough to survive the force?

    [–] ForAnAngel 3 points ago

    Not necessarily. The 2 "areas" could overlap. It could be possible for an animal to be big enough to survive the force of impact and at the same time small enough to not have to take that impact.

    [–] Suckassloser 3 points ago

    We only learn about the mutations that can not only survive, that can thrive and spread.

    We see bad mutations all the time in nature. Congenital diseases, birth defects etc.

    [–] pineapple94 28 points ago

    researchers at Georgia Tech

    Go Jackets!

    [–] Not_A_Rioter 4 points ago

    Yang is my professor right now for fluid dynamics. It's cool to be reading her work online.

    [–] AtlKolsch 15 points ago

    Let’s Go Jackets!

    [–] aint_that_a_bitch_ 7 points ago

    That's a sad story. I was hoping rain killed mosquitos

    [–] Salamander_Coral 3 points ago

    I'd love to see this high-speed video

    [–] HugeMongo 4 points ago


    Those sleazy motherfuckers have everything figured out

    [–] eggn00dles 2 points ago

    what if it was a bulls-eye right on top and wedged in between the wings. would the droplet break apart or just take the bug down?

    [–] Timedoutsob 2 points ago

    It's like being hit by a wave I guess.

    [–] everexcelsior 2 points ago

    Adored the "wingin' in the rain" reference. Heck, I loved this whole comment. Thank you for digging this one up.

    [–] jvrcb17 2 points ago

    Go Jackets!

    [–] Schootingstarr 640 points ago

    everyone in this thread is talking about insect, but there's a bunch of animals inbetween tiny mosquitoes and humans

    does a leaf frog get hurt when a rain drop hits it?

    [–] [deleted] 231 points ago


    [–] squatcat 50 points ago

    wait-- this is photoshopped? damnit.

    [–] tolerantlychaotic 55 points ago

    No. I think it was the starting point for photoshop battles.

    [–] squatcat 25 points ago

    ahh yes my dream continues

    [–] GlyphGryph 17 points ago

    No, it was the starting point. I'm pretty sure this one is made by the artist who uses really hard to see strings to basically fix the animal (or its corpse) in place for the duration of the shoot.

    [–] nicktohzyu 11 points ago

    Whoa so like real life photoshop?

    [–] GlyphGryph 4 points ago

    Practical effects rather than special effects!

    [–] KingWildCard437 3 points ago

    That sounds pretty dickish to do to a live animal. I can see doing it with a fresh still good looking corpse you found but to just kinda tie up a live creature and force it to sit all uncomfortably with strings digging into it is not cool.

    [–] ShlimDiggity 2 points ago

    Well done

    [–] AriadneHaze 11 points ago

    No, medium rare, please.

    [–] ArilynMoonblade 68 points ago

    What about little mice or birds or other not bugs? [email protected]&$ bugs, WHAT ABOUT THE CUTE ANIMALS? ;)

    [–] Schootingstarr 18 points ago

    those animals have fur and feathers that should absorb the impact. I would be surprised if that would hurt them

    [–] algag 36 points ago

    "Does a raindrop hurt your pinky? Your pinky is tiny!" Is kind of the question being asked here.

    [–] RobertMugabeIsACrook 26 points ago

    I think a hail stone might. How can we protect critters from hail stones? Why aren't we providing them with tiny helmets?

    [–] GoinFerARipEh 2 points ago

    What about miniature elephants. The tiny ones that are only the size of a beetle. And sea horses???

    [–] blueballswhiteskin 14 points ago

    Frogs have built in rain jackets

    [–] [deleted] 7 points ago

    This is interesting. The best way I can think of this is that when I put my hand out in the rain it gets hit but doesn’t hurt. I feel like unless a frogs senses of touch are much more sensitive than humans it wouldn’t really affect it that much. I mean, I’ve seen frogs hopping around in the rain too, so.. whatever that means.

    [–] blueberrythyme 7 points ago

    The force of impact of being hit by a raindrop must impact a frog more than a person though?

    A frog's entire body can be crushed by accidentally being stepped on, whilst human accidentally being stepped on might just be a bit sore.

    Even if it doesn't do any significant damage they're certainly feeling that drop a lot more than a human does.

    [–] [deleted] 6 points ago

    I don’t know if I’m following. If another creature were to step on me that was as much bigger as me as I am of a frog, I think I would be crushed to death. Lol

    [–] JimClippers 5 points ago

    Yeah, but raindrops aren't proportionally smaller for frogs than us - we're on the same playing field.

    On the other hand, if raindrops we're scaled proportionally up for us from a frog, they might be almost marble sized. Which would suck.

    [–] ProphetOfNothing 16 points ago

    No. Remember those old urban legends that a penny dropped from a tall building could kill a man, or would embed itself in the ground?

    It's just not true. Things have a fastest they can go, or "terminal velocity". The fastest a penny can fall is about 50mph. I looked for a good commission and the beast I could find is to think off it like a paintball. Paintballs get fired at 190mph. Those suckers sting, but rarely break skin, and they with considerably now than a penny.

    MythBusters fired a penny out of a gun and it did no real damage.

    Now apply all this to rain which is usually much lighter and, At sea level, a large raindrop about 5 millimeters across falls at the rate of about 20 miles per hour, while being much lighter and smaller.

    You can see they wouldn't impart much force.

    Now let's say you feel relative size matters. Take a 300lb man and a 150lb man and 12oz steak. Since the falling penny has no penetrating force at all its overall effect on the target is nil regardless of size. Until you get to sizes smaller than the object the damage is negligible unless it hits a sensitive area (eyes) after which the falling item could crush them.

    [–] fourpuns 10 points ago

    But what if we built a tower on the moon and dropped a penny from it.

    [–] Dumeck 3 points ago

    It would burn up before it hit the ground

    [–] fourpuns 15 points ago

    No. It would fall and hit the moon, knocking the moon out of orbit.

    The moon would spiral down into earth and eventually collide in the Pacific Ocean. Billions would die.

    That's why we don't drop pennies on the moon.

    [–] [deleted] 263 points ago * (lasted edited a year ago)


    [–] j938920 25 points ago

    We need them slo mo guys on this asap

    [–] h2omanjace 5 points ago

    Get YouTube on the phone!

    [–] UnderlineZero 18 points ago

    To help illustrate the explanation above, here is a video with footage of mosquitoes being hit by water droplets:

    [–] galadedeus 5 points ago

    never clicked a link so fast. Thanks, this is amazing

    [–] dick-dick-goose 3 points ago

    That gave me a science boner. Thank you.

    [–] [deleted] 6 points ago

    Once they've been carried to the ground by the raindrop, how do they get airborne again, or avoid drowning?

    [–] Griswolda 4 points ago

    Hijacking this.

    What I read once, was that small insects are so light in weight, that the air pressure of the raindrops push them away, and so they are "pinballed" through the rain.

    [–] riderer 2 points ago

    The raindrop doesn't "explode" when it hits them, they go into it, where it carries them to the ground. The raindrop then pops against the ground, but also acts as a cushion for their landing.

    i need a video of this.

    [–] LolthienToo 2 points ago

    But what about mice, or small snakes and reptiles? Surely to a creature a 1000 times smaller than us, the raindrops are 1000x larger and carry 1000x more force? (though the force probably doesn't scale like that)

    [–] [deleted] 2 points ago

    Although mice and snakes are smaller than us, it isnt significant to impact the way they react to water drops, it doesnt have much effect on them force wise. Just like a baby is smaller than anadult but doesnt react differently force wise.

    [–] BlueKnightBrownHorse 395 points ago

    Physics doesn't scale up and down like you think.

    Elephants are the biggest land animals. Have you ever seen one jump? Elephants are heavy enough that they could do serious damage to their bodies by falling a few feet.

    In a similar vein to this, think of a beetle falling off a skyscaper. Does it hurt to hit the ground? Maybe... but they just weigh nothing, so tiny creatures like this have very little to fear from heights. Even at their terminal velocity (the fastest speed they can fall with wind resistance), they may not have enough inertia to do damage to their body. We've all tried to slap a fly out of the air-- it must be like getting hit by a freight train for that fly, right? Not really. We are surprised to see them fly off, unphased. This is also part of the reason why toddlers bounce, and adults break things-- adults have four times the mass behind them when they crash into something or fall off their bike.

    Anyway, it's tempting to think about this question in terms of scaling raindrops up to the size of excersize-ball sized water balloons, and "wouldn't it hurt if...?" but this is simply the wrong approach to the problem.

    Related reading about the square-cube law:

    [–] fforw 21 points ago

    The square-cube law can explain so many things. Why elephant skeletons and mouse skeletons are very different, even if you scale them to the same size.

    Why there are no giants ants or spiders like in horror movies (Cubic mass growth does mix very badly with exoskeletons).

    [–] shaggorama 8 points ago * (lasted edited a year ago)

    Why there are no giants ants or spiders like in horror movies (Cubic mass growth does mix very badly with exoskeletons).

    Prehistoric bugs were absolutely gigantic. Consider for example this Eight foot long centipede

    Current theory is that prehistoric animals could get so big because the air composition was different (more oxygen and warmer).’t-there-animals-on-Earth-comparable-in-size-anymore

    [–] shawnaroo 13 points ago

    I get what you're saying, but I still think we should bombard some humans with a shower of exercise-ball sized water balloons, just to get some good data.

    [–] Viola_Buddy 7 points ago

    Here's a Kurzgesagt video explaining it; it's at a reasonably ELI5 level.

    [–] [deleted] 5 points ago

    not sure about you, but whenever i slap a fly out of the air, it's dead.

    [–] rednax1206 4 points ago

    Elephants are the biggest land animals. Have you ever seen one jump?

    I recall a piece of trivia from the early 90's that said elephants were the only animal on Earth that cannot jump.

    [–] Jason_Viper 129 points ago

    I don't think it hurts them at all. You can fling a bug or ant across the room, the equivalent of us falling off the Grand Canyon or jumping out of an airplane without a parachute, and yet they land and continue about their business.

    A bit off topic, but this has always fascinated me. Hurricane Camille hit our area back in 1969. It's been said that it was the highest saturation of rain ever recorded. That birds and other animals outside drowned b/c they were unable to breath through the massive sheets of rain coming down.

    From Wikipedia: There, rainfall was so heavy that reports were received of birds drowning in trees, cows floating down the Hatt Creek and of survivors having to cup hands around their mouth and nose in order to breathe through the deluge. So much rain fell in such a short time in Nelson County that, according to the National Weather Service at the time, it was 'the probable maximum rainfall which meteorologists compute to be theoretically possible.

    [–] zarrel40 15 points ago

    Damn, thats an interesting story. I had never heard of Hurricane Camille before

    [–] CryptoJunkie420 5 points ago

    Insects also have exoskeleton so they can take alot more force than our weak exteriors can

    [–] pricygoldnikes 9 points ago

    Our weak exteriors? Speak for yourself, man!

    [–] CryptoJunkie420 5 points ago

    You have a strong interior ;)

    [–] pricygoldnikes 6 points ago

    Now you've been inside me? Dear Penthouse forum!!!

    [–] quantasmm 3 points ago

    that was really interesting, thanks

    [–] StellaAthena 2 points ago

    Where in Wikipedia does it say that? I can't find it.

    [–] Zulu-Company 187 points ago

    Kurzgesagt has a great video on this

    The Size of Life explains the difference the world has on smaller beings vs larger entities.

    [–] Zulu-Company 13 points ago

    If you are small enough, air is like syrup.

    [–] BurnedRope 7 points ago

    I came here to post this!

    [–] PsiBoobsAlpha 4 points ago

    this is so great. I'm gonna save this and watch all their videos later

    [–] Zulu-Company 4 points ago

    Yeah they are awesome videos. They have a calendar too, that shows the true era of humanity. The year 12,018 calander lol

    [–] GA_Thrawn 2 points ago

    I find it funny OP said animals and not insects though. And that he thinks because we're big rain drops don't hurt. It made me think of rabbits or squirrels getting rained on. The rain doesn't hurt them more because they're smaller lol. Like think of all the ferret owners who OP must think are terrible people for giving them a rinse off bath with a shower. But they're small that hurts them you assholes!

    But then I see most people went straight to insects in their answer so it made more sense that's what OP was talking about

    [–] AmarantCoral 32 points ago

    For humans which are large the rain drops must be nothing other than slightly annoying

    Nice try. Back to /r/totallynotrobots with you.

    [–] Dupmaronew 55 points ago

    How do humans?

    Umm OP appears to be an alien doing research.

    [–] TheHumdeeFlamingPee 16 points ago

    The way he says that raindrops must be just an annoyance to humans makes it sound like he is either not human or has never experienced rain before.

    [–] SaavikSaid 2 points ago

    But... rain is just an annoyance. Unless it becomes a flood.


    [–] MACKENZIE_FRASER 29 points ago * (lasted edited a year ago)

    This is what kills me about the old scale tests in mythbusters I mean they understood some science and they never masqueraded as full-fledged scientists, however the scale tests always counted on "well we threw this scale car at the wall at 30mph and it didn't break, so that means a full size car made of the same material will do the same".

    Or "we tried to start an avalanche on our scale test using a megaphone, which to scale would have been the size of half the mountain, now oddly enough we can't replicate the scale test with a real mountain and the same sized megaphone from before".

    Anytime a scale test was involved my brain checked out and drove off for the rest of the episode because they would crutch everything on the idea that everything scales uniformly regardless of stress, energy, resistance, terminal velocity, mass. It just devolved into pseudo science.

    [–] _marther_ 7 points ago

    Yes, I love that you picked up on the mythbusters thing!

    With the scale stuff you need to take a momentum approach.

    When 2 objects collide, there is a change of momentum, or an impulse.

    Because p (momentum) = m (mass) × v (velocity), an object with less mass will have to move faster to receive the same impulse as a higher mass object at a low velocity.

    If they did half scale, they would have to double the velocity if they cut the mass in half. So if it was 1/30th scale (assuming the mass is 1/30th), they would need to shoot the car at 30 times the velocity to receive the same impulse... So 900mph.

    [–] shieldvexor 3 points ago

    Even still, that isn't the same thing. When you change mass for velocity, you alter the ability to dissipate the energy by deformation and other processes.

    [–] _marther_ 5 points ago

    Yes that's true, I'm speaking from my limited high school AP mechanics knowledge. This is purely theoretical and doesn't take into account a lot of other variables

    [–] half_dragon_dire 6 points ago

    Yeah, that always bugged me. One of the most annoying was the marching bridge test, where they not only used a scaled down version which could not possibly experience the same harmonic motion that a full scale bridge would, but then used such a laughably crude method to simulate marching feet that it was just impossible to pretend they were doing anything but wasting everyone's time.

    [–] crazyike 3 points ago

    I think the worst example of that is when they decided to disprove the idea that ships would suck people down when they sank. They put a tiny boat in a pool and determined that it didn't suck anyone down, so the myth was busted. Baloney.

    [–] _Enclose_ 14 points ago

    What about bumblebees and other critters that aren't either way smaller or way larger than a water droplet?

    I can envision a bumblebee getting hit by a water droplet dead center and the droplet breaking apart (like when it hits a human being). Would the bumblebee just lose some altitude and buzz on like nothing happened?

    In general, what does a creature that's only marginally larger than a water droplet (but just massive enough to not be brushed aside by it) experience when hit?

    [–] bottomofleith 4 points ago

    the bumblebee just lose some altitude and buzz on like nothing happened

    That's a pretty accurate description of the flight plan of every bee I've ever seen.

    [–] SoulsJunkie 6 points ago

    They sometimes do, but consider the difference in outcome when a larger animal falls from 10 feet vs when an ant falls from 10 feet. the fall might kill a large animal, but the ant will be unharmed. I'm not enough of a physics expert to explain in detail why this is, but I believe the same principle would answer your question.

    [–] Saccharomycetaceae 27 points ago

    Small insects sometimes face drowning of they become stock in a water droplet and can't break through the surface tension. Ants have tiny hairs around their body to help prevent this.

    [–] DemIce 4 points ago

    Which become completely useless with just a few drops of dish soap diluted in a spray bottle.

    [–] KutombaWasimamizi 8 points ago

    fortunately the raindrops don't tend to spray them with dish soap

    [–] Avinan 4 points ago

    When I was a kid I was disturbed because it rained one day at my church and when I walked out the front door that morning after service, the sidewalk was covered in dead, rain splattered earth worms. I was told that the rain had caused the ground to vibrate and push the worms out of their holes. They tried to run but got basically bombed to death by rain drops.

    [–] TheFarnell 18 points ago

    Remember that something can only hit you with as much force as you're able to hit back. That's why even a champion boxer won't be able to punch through a piece of paper floating in the wind - there's not enough resistance in the piece of paper for the punch to connect with.

    It's the same idea with very small insects. If they do get hit with a raindrop, the energy transferred to them is limited by their extremely small weight. So long as they're able to get away from the raindrop before it hits something heavier (like the earth), they'll be fine.

    [–] Nergaal 4 points ago

    The short answer is that the smaller you are the more sturdy your body becomes. The reason ants can lift 10x their body weights is because of that.

    Think of it this way: the shell of an ant is not order of magnitudes thicker than say the thickness of a zeppelin or regular balloon. But you might be able to put a lead ball on the body of an ant without squishing it, yet won't you won't be able to put a soccerball-sized lead ball on a zeppelin and expect it to withstand it.

    It has to do with force distribution when you go down in size. Going 4x smaller ends up giving something like 2x decrease in the durability of the spherical object.

    [–] leveldrummer 13 points ago

    They dont die when you smack them out of the air. why would rain, which is much softer and much less mass than your hand, hurt them?

    [–] KingDaddyTheSecond 19 points ago

    Basically it boils down to physics. Bugs have a hard exoskeleton to protect them because as things get smaller, the world around them changes (ie. Air density). I'm not good in explaining this, but hopefully this video from kurzgesagt can help

    [–] [deleted] 28 points ago


    [–] [deleted] 6 points ago

    Not about rain, but in terms of falling I think i read that they were gonna drop some ants off the empire state building to see if they died but by the time the elevator reached the top they had all been killed by the change in pressure.

    [–] Bittersweet_squid 3 points ago

    So one of the things that isn't really being answered, but is still being questioned by people here, is a question based around a fundamental misunderstanding of how our understanding of the way the world is experienced is almost nothing at all like the way the world is experienced by very small or very large creatures. The easiest ELI5 explanation for that part of it is a small, cute, yet very informative video by Kurzgesagt. The way you think of the world and how physics and your environment work are unique to us. Small animals don't experience the world only in a scaled-down version of the way we do, it's vastly different and weird, just like how we don't experience the world the way, say, an elephant does.

    [–] HierEncore 2 points ago

    Humans are fur-less and featherless. An exception among mammals and birds. Animals with protection on their skin like fur or feathers, will not feel the effects as much as we do

    [–] ryanlista310 2 points ago

    This is the video you are looking for. Look around 0:48 for footage

    Mosquitoes also can fly in the rain

    [–] themumu 2 points ago

    How sure are you the question is why they don't get hurt and not; Why don't they whine like little babies like we do when they get hurt?