How to Make a SARLACC PIT

– It’s not the teeth nor the tentacles that make a Sarlacc pit so dangerous, it’s this. Let’s get technical. (burping)
Oh! Oh, right in my face. (upbeat music) The Sarlacc is one of
the most famous creatures in Star Wars Canon. No, not that one.
(hand smacks) It’s a giant desert dwelling beast that spends the majority of its life burrowed in the sand waiting for hapless passersby
(screams) to fall into its great spiked maw. But, although nerds over
the years have added a ridiculous amount of additional biology to this creature, if this was a real immobile creature, despite any digestive times, it would still want to
maximize the chances that something would fall into it so it could get some food. And that’s why I think we
can ignore all this biology for just a second for some physics. A Sarlacc has tentacles
(water splashes) and rotund crime bosses
(air whooshing) to help feed it, of course,
(screams) but a creature like this can’t always just rely on
proximity and punishment and that’s why I think this pit itself is expertly engineered by the creature. And the reason why
(water splashes) is frict–
(hand smacks) Friction. Stop it. When an object like this is
sitting motionless on a slope, there are two forces acting on it. The force of gravity, in other words, its own weight, and the frictional forces supporting everything from sliding down. When this static friction
force is at least equivalent to the horizontal component
of the object’s weight, then everything is balanced,
equal and opposite, and nothing slides down the slope. The force of static friction
will always be some fraction of the force that the
object is pushing down on the slope with and what that slope is
pushing on the object with, the normal force. So, this coefficient right here is gonna determine
whether or not a surface feels slippery or not.
(water splashes) (hand smacks)
Stop it, Kevin! For example, the coefficient of friction
between wood and ice is just 0.05, which means I can’t tilt this board very far at all, as it will take just
5% of the normal forces ice cube is pushing down on the wood with to (ice drops) dislodge it. Ice is slippery. Heh. On the other hand, and in my hand, the coefficient of static friction for human skin on metal is a lot higher, which is why it feels
like metal can basically stick itself to you at high angles, but no matter the coefficient, eventually it will fall off a slope, anything will. And at sufficient steepness, a slope can slip past itself. (coin flips) (hand slaps) (coin drops) What is the steepest
a pit can possibly be? You’ve never seen a
straight up and down tower of loose, dry sand that’s rough and coarse and gets everywhere, nor have you seen a large
slumping pile of boulders. Different materials have
different static frictions and therefore, will naturally
settle at different angles. For example, we would
expect loose, dry sand to naturally settle at
a more shallow angle than something like a
pile of huge boulders. These angles, no matter what they are, are the material’s angle of repose, or avalanche angle if
you wanna sound cool. This is the angle at
which a pile of something can’t be piled any higher. The slopes will slip and slide on themselves and it’s so easy to measure
for different materials. Let’s do that. The avalanche angle is
probably the easiest thing you can measure about a material, because to find it, all you need is that material, a lot of it, and then you
delicately pour the material out until it forms the
highest pile that it can and then you measure that
angle off of horizontal. And how big that pile is gonna be depends on the material itself, the particle size, how
those particles interact, etcetera, etcetera. For example, sand. As we said, sand has a relatively
(sand pours) low angle of repose, so as I pour it out here, you can see that the angle it is forming is pretty shallow and this makes sense with what we see in the world too. Sand dunes, if they don’t have a lot of dirt in them, just don’t get that high. You can see the angles here, slopes not supporting its own weight very much at all. And then there’s something like flour, which is a lot finer, particle-wise, than the sand we just used. So, if we try to find
the angle of repose here, you can already see that the slopes the flour is making is a lot higher than the sand, and again that depends on particle size and how they interact. You can see the angle here already higher than the angle of repose for the sand. And then there are materials
with much larger particle sizes like breakfast cereal. The textbooks don’t exactly have an angle of repose for this, so let’s figure it out. (cereal crunches) (laughs) Now, I’m no material scientist, but that looks pretty close to the flour, if not higher. 40 degrees or around 45 degrees. This is about as high
as avalanche angles get. Add it to textbooks.
(cereal crunches) This critical angle also
depends on what else is in the material. If I put some water in the sand that we just used, the water would fill up
the interstitial spaces in between the sand particles and then electrostatic attraction would help kind of bind
everything together. And this interaction gives wet sand a much higher angle of repose than dry sand, which is why you can build sand castles out of (laughs) wet and or damp sand with a, basically a 90
degree angle of repose, but you cannot build
an equivalent structure out of perfectly dry sand. Why are all these little
demos important to our topic? Well, let’s think like we’re the Sarlacc. If we want to increase the success rate of prey falling into our spiky maw, then we would want to make sure our slopes are as slippery as possible, that these slopes are at the
avalanche angle, specifically, and so this is what a Sarlacc
pit would really look like. If we pour some sand around
our makeshift pit here and do so (sand pours)
until everything around it reaches that angle of repose, we will have found the angle
at which the success rate for the Sarlacc increases. It looks like I’ve reached it now here. Right now you can see that even the slightest touch to the slopes of our tiny demo Sarlacc pit
(Sarlacc growls) will collapse almost
instantly upon any down force. And this is what the Sarlacc would want if creatures were wandering by for just the slightest
step to bring it down into its mouth. I know it sounds weird to
suggest that an alien sand beast would go through all the
trouble of engineering the pit that it sits in, but in our own galaxy, there is actually already a
creature that does just that. This is the antlion, well more specifically
it’s an antlion larvae. The adults of these larvae look
something like dragonflies, but the larvae are much more famous on account of their voracity. I’m fascinated by these little insects, as are scientists, because they have a fairly unique way of getting food. In their larval state, they find a suitable patch of sand and then they start digging, and they start digging in
circles of decreasing diameters until they’re at the very bottom of a perfectly conical pit, jaws out, waiting for
something to fall down into it. Does that sound familiar? If anything is a real world Sarlacc,
(screams) (Sarlacc gulps) the antlion is it. And here is where all of our talk about angles of repose comes in. Studies of antlions have
shown that antlion pits are almost exactly at the angle of repose when they are built in the sand that the little larvae choose to live in and they accomplish this by sitting at the bottom
of their conical pits and flinging sand up on the slopes, 360 degrees all around, until those slopes can barely
support their own weight. They are devious little civil engineers. The end result is a pit with
slopes ready to collapse at the slightest step of an ant. Sand slides then aid in bringing that prey down to the awaiting jaws of the antlion and then.. Whoa, come on man, he’s already, come on, he’s already dead. So here’s what I’m suggesting we add to fictional Sarlacc biology. First the creature finds a
suitable spot in the desert, very, very dry sand with
small particle diameters. Then the Sarlaccs, perhaps
with their tentacles, engineer the slopes just like antlions to make friction work on their behalf. Then all the Sarlacc has to do is wait for some ancillary
character with no backstory that the fans only started
liking because of his helmet to wander in and fall down into the maw, (screams)
unable to provide the necessary down forces to overcome the sandy cascade of doom. (inhales deeply) This isn’t just a pit. It’s a physics-optimized hole of death. (rocket engine roars) So, how do you make a
Sarlacc pit with science? Well, I think you recognize that if this were a
giant immobile creature in the middle of the desert, it would probably be the kind
of natural structural engineer that evolution made the antlion to be. I think that this is like
some kind of pitcher plant out among the dunes and that the sand and the pit itself is just as important as the
tentacles and the teeth, because science.
(water splashes) (hand slaps)
Save it for the special edition, Kevin! (upbeat music) Do you know what else is
interesting about antlion larvae? They don’t poop. They don’t even have an anus. They just sit there in the desert, eating ants, filling up with feces, no place for it to go until they mature into their more dragonfly-like state and then they develop an anus and then they can release it. Imagine the majority of your life
not being able to poo and then later on when you’re like relatively
speaking like 60, then you poo. ‘Cause the dragonfly state
doesn’t live for very long, but the larvae does. So, holding it in. That’s the definition of holding it in. (electronic music)

About the author


  1. Thanks for watching, Super Nerds! I love doing the practical mini demonstrations. And you're right — weirdly, when filming this, I thought I adopted a kind of Bill Nye cadence. No idea why… — kH

  2. "Yo, wanna do the Dragonfly challenge?"
    "What is that, Timmy?"
    "You hold in a poop till you're 60!"
    "…Timmy, what is wrong with you?"
    "I'm already on week 2!"
    "TIMMY NO!"

  3. 1:24 Technically there are three forces acting on the object. You forgot about the reaction force (or normal force) of the ground on the object! </nerd>

  4. So, I'm not a huge Star Wars nerd but the comparison between antlion larvae and sarlaccs brings up an important question: what is the adult stage of a sarlacc? Is there anything in star wars canon that's big enough to be an adult sarlacc? If not, then what if it's already in its adult phase. It can't be an insectoid because the chitin wings just wouldn't hold up. What if instead it was a cephalopoid. The beak and tentacles would match at least that much. And another thing: the asteroid worm. It seems to act like a massive bobbit worm, striking fast but also somewhat rooted into their spots. I think that in the star wars universe there was once an interstellar ocean of sorts. And now all the small spacefish that move around are extinct and the only remaining creatures are the massive, unmoving behemoths with slow enough metabolisms to still be digesting a long dead spacewhale.
    Edit: sorry for the terrible formatting and grammar. Its 5AM and I can't sleep.

  5. wouldn't a Sarlacc also need some sort of paralytic that is contained in the creatures its swallows to prevent them from clawing there way out? it's obvious the tentacles are just graspers and hole fixers. the beaks tongue likely contains a paralytic in the thick saliva that is potent enough to be absorbed by the skin of the victim. Or would it, the 100 meters fall on to the hard beak or spine thinggys be lethal to most anything over the size of a kitty, cause you do not mess with the kitty and live.

    Side note: my favorite video is your first one on Godzilla nad since i first saw it in 2015 i have been thinking about how they could function couldn't a Titan like Godzilla have there nurvise system enhanced if the part of his brain that controls movement has quantum entangled particles at his articulation points, thus allowing him to move at the speeds he does via quantum tunneled nerve impulses sent to the nerves.. given he is a huge creature he could have a series of secondary hearts that help move blood faster. then instead of traditional cartilage, some form of silicon rubber takes its place. he could have something like iron, titanium or tungsten cables for tendons instead of whatever it is tendons are made from in non-titan species. biology does not really interest me outside of Titan/kaiju biology.

  6. I know this won't get onto footnotes but worth the try. How does the sand that falls along with the prey get replaced? I mean if u keep losing the top sand eventually(which it has to to make the prey fall cuz of friction) the slope starts to flatten so that's not ideal for a sessile creature.

  7. hey kyle, in the last video you mentioned you had hair superpower, very much like medusa (from inhumans). It got me thinking on how did you got those powers? was it because you used to much argan oil? did you accidentally exposed some argan oil to radiation? or is it a plain mutation?

  8. Another thing antlions do is flick bits of sand at things that fall into the pit to make it fall in faster. You can feed an antlion just like you'd feed the sarlac by dropping an insect into its pit. They react almost immediately to anything on the slope.

  9. Hey Love the show check this sarlacc pit

  10. Anakin: its course, and it gets everywhere.

    Sarlac: Stop complaining, at least you don't have to get it out of your teeth and back of your throat all the time!

    All jokes aside, there are 2 major differences between the ant lion larva and the Sarlac that are worth mention. Anatomy and size.

    Anatomy: from the images and drawings you showed in the episode, the ant lion larva doesn't have a gaping maw resting open like, say, a Venus flytrap. It looks like the pit brings the prey down, and then the ant lion larva uses pincers to dispatch it. Therefore the Sarlac, with it's gaping maw, is going to be eating a lot of sand. I imagine it would have some way to deal with that, either by some way of separating the sand from the prey and regurgitating it, or by a digestive system that has evolved to digest vast quantities of sand.

    Size: this is more of a tie in the the mouth/sand topic, but because of the ant lions size relative to a grain of sand, it seems it would be easier for him/her to avoid accidentally ingesting sand than the Sarlac. To the Sarlac, sand behaves like sand, but to the Ant lion larva, sand is the size of playground balls!

  11. How to make Sarlacc Pit.
    1. Go bury your self in sand.
    2. Face up.
    3. Open mouth wide.
    4. Vibrate.
    5. Eat everything that falls in your mouth.

  12. I've never seen a straight up and down tower of loose dry sand, eh? Hang on a minute, Imma go boot up Minecraft real quick.

  13. I saw an ant lion irl (in action eatting an ant) already and I predicted the w-hole video from the star-t.. I didn't know that making puns is so fun. (for the 1 that makes them)

    like yrs ago

  14. "allthesarlacchastodoiswaitforsomeancillary characterwithnobackstorythatthefansonlystartedlikingbecauseofhishelmettowanderinand falldownintothemaw" …this is the way.

  15. I'm wondering if a creature as huge as the Sarlacc could find enough food to survive in the middle of nowhere only by using this strategy. It would eventually have to move from spot to spot, searching for more populated areas as the other creatures avoid going there, right ?

  16. 1:25 Um, no. There would be 3 forces (if your diagram showed all 2 forces then the object must be accelerating in some direction), the third force would be a reaction force, the same thing that stops you falling through the floor. That assumes you have a floor in the Void. Although you do add the extra force at about 1:48.

  17. Hey Kyle, finally got around to watching The Expanse from all your recommendations (I love it), and I was curious about scenes when people are bleeding out in zero-g.
    Would it make blood easier to pump because it sticks to the arteries’/veins’ walls and doesn’t need to fill the interior or would it be harder because it would collect into a giant blob and not move at all?

  18. Hey Kyle, love the show. You’re basically implying that you’re going to make giant genetically engineered ant lion larvae that will always be ready to snap up any heroes who try to infiltrate your base by foot. Very clever, but I know how to thwart your evil villainy scheme. We’ll just bring enough water and dirt to increase the angle of repose of the sand and reduce our chances of falling into each pit! I’m pretty sure that some ants might evolve this defense mechanism as well millions of years in the future, spraying copious amounts of water or something else from their abdomens to increase the angle of repose to escape the antlions.

  19. It is a good video and makes a lot of sense, for the sarlaccs on tattoin or other desert planets but on Felucia for example there is a faint sarlacc without any nearby slopes or sand.

  20. Hi Kyle, love the show!
    You say in this video that a Sarlacc found a perfect place in the desert then dug its pit in the ground but it is immobile and therefore could never find a place for a pit. So instead do you think that possibly like the ant lion larva it can move but then becomes immobile later on in its developmental stages because otherwise it would be perpetually stuck at its birthplace never finding a new pit place.

  21. Hows it hanging I'm just wonder how does the sarlac pi stay alive? I mean it never seems to move and it apparently takes thousands of years for it to digest its pray, And a creature its size must need a lot of ATP. Mybe it's a plant and has roots that go super far down but then it would half to use more energy to perform that capillary action! Or mybe it secretes bacteria that find organic juices in the sand and go back to the main body, mybe the sarlac is not even a biological creature but Like a gaint virus because it kind of looks like rabies, also I heard that they reproduce by infecting a living creature and pouring out there…… spores…. dang it. Welp what ever the answer is I don't no. Anyways what are you thoughts dude

  22. Hi Kyle. Got maybe a stupid question for you to do with G force or if anyone in the comments can answer this for me.
    If you where about to face more then normal G's would taking blood thinning tablets make it easier for your heart to pump the heavier blood around your body therefore reducing the effect of the g force or wouldnt it matter as your blood would still retain the same mass?
    Tell me if thats a stupid question. Love the show. Your a funny dude. Hows life in the void?

  23. Hi Kyle , love the show!

    i heard a very suspicious thing while you were talking about the sand lion, you said it was found in our galaxy, that kinda confirms that you are some sort of interstellar alien traveler that came to earth to teach science while planning to conquer our little blue planet through some sort of evil plan that we are just finding about…. there are too many clues by now!!

  24. @Kyle. I am new to YouTube's comment feature, so forgive me. However, one of the over scoping themes, especially in your Because Science Footnotes" series is the morality of scientific research. I also know that the expanses is a favorite show of yours and you turned me onto it, and its incredible fyi, however in season 2 episode 11 approximately 32 minutes in, how do you justify the data already accumulated through inhuman methods and a moral scientist's methods? As a member of an armed force I would DC like to know your arand point on take in g information gathered inhumanely to help mankind vs abandoning that information, because it was obtained in an immoral manner.

    A long time viewer/first time commenter

  25. Completely unrelated but If wolverines bones are simply coded in a unbreakable metal then couldn’t his bones be shattered by say a strike from Thor’s hammer? so if his claws were striked and the bones within the metal was broken how could he heal with the bones in the way ? I hope this makes sense and I hope u answer I love ur videos man 👏🏽🤷🏽‍♂️

  26. I used to be a soil lab technician and this is one of the things we used to test in the old lab, the angle of repose, especially for sandy material that would be used on construction sites. This hit so many old little things I had gotten used to but my friend whom I watched this with had no idea about.

  27. Just think about how good it feels for the antlion to do that first poop. Also, I think that's the animal that Kahn put in Chekhov's ear in Star Trek II.

  28. tenticle trying to touch Kyle
    "Save it for the special edition, Kevin!"
    Just what kind of things are gonna be in this special edition O_O

  29. Me at 7:50
    "Wait, wasn't there a Henry the Lizard episode about an insect that did pit-traps like that? The Lion-Ant or Ant-Lion or something like that?"
    Kyle "The Ant-Lion-"
    Me: "Hah! I got it!"

  30. So here's the real question: if Ant-Lion larvae are the stage that dig pits, does that suggest the Sarlacc itself could the the larval form of something, and no one knows, because it's larval stage last literally millenia?
    What kind of bizarre adult would it form???

  31. Just so veryone knows, Kyle is writing on a big pane of glass with it recording from the opposite side of the glass. His mic makes it to where we can here him. Though, it would be backwards for us if they just put it up like that, so they mirror the video and post that.. if I'm wrong, someone correct me, but that seems to be the most plausible way to get the effect we see.

    Love the show, Kyle.

  32. Why are you pouring the sand around and around? It’s obviously going to make for a lower mound than if you pour it in one spot (like an hourglass would)

  33. Fun story, if you put some sheets in the sand, it dramatically increases the shear strength. There’s a great video by Practical Engineering demonstrating this concept.

  34. That was awesome and I'm really into star wars.also KH if you don't mind I'd like to run an idea I have for a future episode of because science by you using the comments since I missed the contact info,my idea is about just how plausible the existence of Transformers,the robotic space aliens not the things that the electric company deals with,are in reality.

  35. Perhaps this has been answered at some point but if Colossus becomes solid metal does that kill all of the bacteria in his body? I can Imagine him having terrible bowel problems after every battle and needing to keep probiotics on hand.

  36. I've seen sand dunes much steeper than that such as the ones in Rexburg Idaho or the ones in Panama City Beach that are like cliffs. Of course those have plants growing in them but then there's also the ones in New Mexico that are made up jipson near the Air Force's missile testing site near where the 1st atomic eas tested. those ones are steep enough to sled down.

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