The "Mountain Or Valley?" Illusion
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- čas přidán 28. 06. 2017
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This video is about a multistable perceptual illusion, similar to the hollow face illusion, whereby maps or aerial or satellite photos look upside down/inside out, ie, concave (valley) parts look convex and convex (mountainous) parts look concave. Just flip the images around and things will make a lot more sense! It's just because our eyes gauge depth based on the location of shadows, and the sun always casts shadows on the bottoms of things.
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REFERENCES
Twitter posts:
/ 859799730565414912
/ 859800278358528001
Bad Astronomy Blog post: blogs.discovermagazine.com/bad...
Multistable perception en.m.wikipedia.org/wiki/Multis...
Top-left Lighting en.m.wikipedia.org/wiki/Top-le...
Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute!
Created by Henry Reich - Věda a technologie
1:48 turn your screen upside down. Man that's trippy
+
But I'm on a computer...
FrodoTheDodo I did as instructed.
Then my screen auto rotated
take a screenshot and flip it
@Muffycat: Then press Ctrl + Alt + Down.
»If you didn't grow up on earth, please let me know« 😂
UK isn't part of earth? Jesus...I think I misunderstood Brexit...
ZeroSum23 haha 😂
ZeroSum23 o Oh god we're leaving Earth now as well? Brexit is even worse than I'd imagined! Are we expecting to get a trade deal with the Venusians now?!!!
brandybuck1984 let's just hope we don't leave the solar system next.
*2 weeks later*
Government: I have an idea let's leave the solar system!
Me: jinxed it :(
Even worse: Uranus.
...Okay I have to apologize. That was a shit joke.
“If you were a human that grew up on Earth”
R E L A T A B L E
@Biological Donut “were”?
Y... yes, were, i f you were... the only other two variations of “were” are we’re, which is “we are” and where, as in where is that thing. If you Were a human is correct.
Julia Rainbow
The thing I was trying to emphasise is the fact that it was in past tense, implying that that’s not the case any longer.
@@godofallpotatoes1614 I mean in 10 years there'll be people in mars, so lil' Jimmy the Martian will see this video and get confused
@@godofallpotatoes1614 no. "If you were x" Is an unchangeable phrase. So the tense does not matter.
I never see it right. The grand canyon is a mountain range at every orientation
Same
me too
same i looked at it too long the first time and now it's stuck 4 me
Same
Same!
I didn't grow up on earth. I grew up in the US
I grew up on uranus
You can't grow up on Earth, if you don't grow up at all...
Is England also your city?
+Jomer Tomale
No, England is my State
A perfect example of Poe's law.
"What am I Patrick?"
"Uh, a mountain?"
"No, I'm a valley."
"What's the difference?"
ChromeVault What about it being a reflection in water?
BAHAHAA
BUHUHHHU
I can here the voice of patrick god
A mountains? A sky. A windmill!
666 likes
The grand canyon doesn't do it for me, I can't see anything else than a mountain
Try closing your eyes for like 10 seconds as you’re turning the screen upside down so u don’t see the switch
Albin Liungman now I see it, but that bottom part still looks like mountains
For me it helped to look at that cloud/smoke plume and its shadow since my brain latches onto its correct orientation much more easily
I can
The described phenomenon has a practical reason; cartographers used to work with paper maps on desks. Since most people are right handed, desk lamps (and candles, in the older days) are usually positioned on the left side of a table, so that you‘d have the written words illuminated while your hand casts it’s shadow away from the writing. So in order for cartographers to not get confused, the shadows on maps are oriented so that they would line up with any other shadow on the desk!
That's so interesting tbh. Thanks for sharing!
didnt know that but it makes instant (clicking) sence - thanks
this is why u use freaking colours to mark heights.
in photos...
@@georgf9279 those photos looks pretty much black and white to me. if real time colour even looking from above wouldnt make u confuse.
Vinh Pham they arent edited
what system do you see most commonly?
doesn’t even work for me: a colourblind person lmao; have to use numbers to mark the heights
2:30 Uhh... Your lips are looking a liiiiiittle chapped there, bud
The Nuggernaut greatness
And now i cant unsee it
Lol
Look at those dry crusty lips, be looking like a shriveled leaf.
@@islandprincess714 thanks a lot now I can't unsee a shriveled leaf
1:48
Me: *turns screen upside down*
Librarian watching me rip screen off desk: *ಠ_ಠ*
Haha
Mountain: You're weak.
Valley: I'm you.
nice
I got that!
PBS Space Time, Numberphile, Veritasium and Minutephysics on the same day? All that's left to break the internet now is CGP Grey.
Feynstein 100 what about vsauce?
+Anuj Gupta Eh stopped watching him a while back. But okay. Let's add him to the mix.
fair enough, tho he really only makes like 1 video a month
*year
Alien FeelsBadMan
What if it is a superposition of both a mountain and a valley.
The Centalist vsauce Michel here
It would collapse into a plain.
is it really both a mountain and a valley??
or is it??
A Vatain or a Mounlley
1:50 it takes me a little bit of mind effort to perceive "Concave" as actually concave, most of the time I perceive it as convex as well. I wonder if it's bc I'm more used to artificial light sources than sunlight, which would mean my brain will usually perceive the light as coming from whatever direction is opposite to the shadows.
That's crazy, it's the complete opposite for me. I can see both "Concave" and "Convex" as being concave, and takes me a bit of effort to see the "Convex" as actually convex.
welp, i was able to see convex as concave and concave as concave, and both looked convex. this illusion is mind blowing
When your local physicist becomes a psychologist.
That grand canyon picture is the best. I cant stop myself from flipping it over and over. It clearly transitions from mountain to Valley and it's blowing my mind (this is after doing a perception course at uni where we went over depth perception thoroughly)
You could tell it was the Grand Canyon... rivers don't run across the top of mountains... ;)
Ooooooh snap!
They also don't erode out of the ground.
But they DO erode the ground!
I didn’t grow up on earth. I’ve been on earth my whole life, I just never grew up.
K
@@mahparanuren1514 hahahaha
uh hu
The weird thing is that I can flip them in my mind without flipping the image which freaked me out when I was little because I was looking at a math problem with one of those see-through and I thought the image in the book changed. My parents didn't understand that though so they thought I had some mental issue. 😅 Later when I understood this concept I tried really hard and did it in real life with a clear cube and basically it looks like the front and back faces are switched which is really weird. Its hard but I know a few people who can do it too.
I never had to study for geometry,
I was a "human" born on Gallifrey... We continually suffer from this problem due to our two Suns
ಠ_ಠ
Lmao this comment is amazing.
Having grown up on Tatooine, I can relate.
Vartika Singhai I'm from Trenzalore and this fucking truth field sucks balls.
On Alderan we used to have this light grey moon
Ooooooooooh that outro was dope
Thanks! Was fun to learn how to do, maybe it will show up in other places (though I really want to do it with hand-drawn art).
minutephysics
we would love to see hand drawn minutephysics..
but the animation is really 💗💗
Real Engineering neat it's real engineering
I'm not from Earth, I'm from Missouri.
(If you get that reference, you have earned my utmost respect.)
same reply
Ya, that's on earth😂
I do understand that reference
Yeah that's on earth dipshit, what are you hustling on us for?
You shoot my guy I blast yours!
All u need to understand this is:
1. Perspective
2. Light screwing us over
*I didnt grow up on earth*
ALIEN! Can we be friends? (jk :C)
Me either. Tarmac and carpet.
Are you still small?
*deported*
Lusitani Mendes I stopped the video and read it too
1:50 initially I saw the Concave one as Convex, and then I could see it both ways. I don't spend much time outside...
Nicholas Braden
I didn‘t see any difference between all the maps he showed etc.
_I never go outside_
The Unicorn Neither do I
#nevergooutsidegang
I was looking for quirky toxic comments like this.
"If you are a human that grew up on Earth..."
7.8 billion people: *raises hand*
Thank you for this Henry! I'm trying to get into cartography and didn't know this. I've watched MP since more than a decade ago (almost 2 decades?) and my kids love the new channel in Spanish minuto de la Tierra. Glad you now have a great team on those channels and still making this short physics videos. Thanks!
You're missing some eyes there Henry.
At least he has a face
Why do I suddenly see KSP profile pics everywhere when I just started playing it again ?
Its not because the KSP secret police has been following you around.
ZockerTwins frequency illusion, sorta
No eyes is very common in cartoons. See Dr. Suess books, for example...lots of characters have their eyes closed. And none of the people (or cats) in Henry's drawings have eyes. Ditto xkcd, come to think of it.
Probably having something to do with "eyes are the window to the soul" or something. "Soul" being difficult to capture with a stick figure. Plain dots might work...
The text flashing text is at 0:25, 0:51,
Duffy United I
2:36
Me who sees it it the other way around: BOI
Wait how do I see the first pic as mountains on mars?
Put your phone upside down
I first noticed this illusion while staring at textured drywall as a kid. With some practice I learned to force my brain to switch between the two.
cool
You must've had a fantastic childhood.
we have no context surrounding why they stared at the wall
phew, glad i wasn't the only one
Noctudeit How sad. That never worked for me because my brain has depth perception.
well, I say this video was very *_lit_*
Ba dum tssssss
I have a pun too, but it's a bit *dark*
L.O.L. Good one's.
Get out of here
_lit_ erally
I spent almost all of the video thinking "He's overstating this a bit, or at least it doesn't affect me as much as others." Then the example at 3:11 came up, and it broke me. Great video.
Wow, this is fascinating and neat! 👍🏻😀 Very well done!
1:15
...Windows Vista with virtual machine running old Windows 7?!
Architector #4 Whoa wtf
Virtual malware work station?
Must be a scam troller
Or just a screenshot
1:50 I see those both coming towards me though...
3:19 and oh my god, everything is a mountain. In between every mountain is a mountain instead of a valley...what is happening?
You have problems.
Bovine Intervention 1:50 i see it yoing in and out
ya same exept i saw both at the same time
Might be based because digital art often has non traditional shading and lighting and minds grow accustomed to this.
This also applies to those objects that are hollow, but when you look at it and move, it looks like it’s following you.
i didnt grow up on earth, i grew up in my childhood home. Wonderful views floating through space!
Mountain, valley, what's the difference?
EDIT: Now I know the reason why I failed college
I failed kindergarten
Eighth Grader Prodigy Explains Calculator Something about your ridiculous username prompted me to briefly take a look at your channel, and my god you aren't nearly as intelligent as you think you are. I know countless people who were much farther along at your age. Yes, this reply is incredibly petty, but something about the way you present yourself made it feel warranted. Unless, of course, your entire channel is very well done satire, in which case, kudos.
I failed my parents
I understand that OF COURSE there are people my age or younger that are by far smarter than me, but at least I am more than average, at least I'm learning derivatives and Vectors in the Eighth grade and at least I made about 5 new theories that are just waiting to be published and revolutionize our understanding of the universe and hey, I may not be the smartest but at least I'm smarter that normal and also at least I'm publishing videos about the stuff I know and contributing to society
" at least I made about 5 new theories that are just waiting to be published and revolutionize our understanding "
Like what?
JUSTICE RAINS FROM ABOVE!!!
Just ice from above?
UnderScore Why tho?
Cheers Love The Calvaries Here!!
or shoots up from below
JUSTICE AHHHHHHH
I love imagining the guy seeing his card upside down, putting it back right side up, realizing that it's a fun and interesting phenomenon and writing a video about it no matter how obvious it is.
Guy: so this is the grand Canyon
See mountains or valleys?
Me: I see a mass jumble of random lines and colors
Edit: Wow 4 likes...
That's a record
My highscore was 2
Concepcion Ponce My high score was 2 too
Wow noobs
Seriously?! your highscore was 2 on a comment. Mine is not 10, not 100, NOT 1000, But a whopping 3
Kidz Vidz XD
@@jordancooper2038 I love your name
But what if you weren't born on earth? *X-Files theme song starts playing*
I need to know!
_seinfeld theme song plays_
Muffycat 101 No not x-files, it sounds like a Vsauce video
Muffycat 101 😂😂
Earth is my city.
Alex haha *kill this meme*
Look up earth TX, it's the place on earth called earth
Ohh cool..mine is Uranus!
The Milky Way Galaxy is my city.
The thumbnail "Mountain Or Valley"
Me: What do you mean? All I see is a M I R R O R
0:51 well, in the future we will live on Kambor, but it's just earth 2.0 really. You should visit me on Freddie street sometime. Oh wait, this video was made 20000 years ago. Crazy how long CZcams survived.
To me the gray "Concave" and "Convex" look like they are both sticking out jo matter how hard i look
That means your eyes are broken. I find it helpful to scoop them out with a Melon baller and then put them back in again
Same
Izamanaick What if i won't be able to see what side of it is concave, and then use te wrong one?
Look harder
Keyboard That's because you probably put them in the wrong socket. When you take them out look on the back. It should have an L or an R next to the Made in China stamp.
I have a defective eye so I don't have any depth perception, so shadows are really important to me seeing the world.
The Robot Pig / lol i thought you said you had a 'detective' eye
aww i feel bad for you, never knowing the awesomeness of 3d monitors or virtual reality..... but then again a flat image on a normal monitor will look just as good, im confused and feel bad for myself now lol
The Robot Pig I feel u
depth perception relies on the triangulation of objects from both eyes, but it's near impossible for people with glasses as well like me, so shadows are important and 3-D videos don't make sense
I have a very dependent eye, so my depth perception was pretty bad too. I remember my optometrist showing me a bee that was supposed to look 3D, but it only ever looked 2D to me. Old 3D movies wouldn’t look 3D. The real D 3D is better though- either that, or my right is less dependent on my left than when I was younger.
I used to do try and switch the concave and convexity of the lines on my ceiling when I was little
oh my god the tittle mountain or valley illusion written with actual mountains and valleys is so creative! 0:21
I LOVE THAT ENDING STICK FIGURE ANIMATION!
Henry : "If you are a human who grew up on earth"
Me : "The video's not for me " :(
The text on the board in the second example is probably cut into the wood, since the opposite would be significantly more difficult to achieve.
I've been wondering about this issue for ages, came into the video thinking it wouldn't actually explain the issue to my satisfaction, but I was wrong. It really makes sence, and works!
I didn't grow up on Earth. I grew down.
I grew up on a planet in the close vicinity of Betelgeuse.
great explanation
In the Duck Rabbit illusion, I mostly see a Duck.
i see both "convex" and "concave" as convex. is something wrong with me?
dummdumm muddmudd you’re a synergistic synesthesia person
It could just be your perception. Nothing is wrong per se.
yea, you got downs
same
dummdumm muddmudd 0:51 did you grow up on earth?
I found lots of them only half worked. For example, at 1:48, Convex should have had shadows extending past the bump, casting a longer shadow. Concave, on the other hand, had some oddities, like the inner sides of the lower left corners of 'o' and 'c', that gave it the impression of being convex, but having been spray-painted black or something (odd that I feel this rather than feeling like the light source was on the bottom right).
I think the Grand Canyon picture worked so well because it has many layers and terrain colours, so it is hard to know where shadows would be, if it were a mountain range.
I get this illusion the most when doing my 3D rendering work, trying to tell is a normal bump map is coming out of a model or going into it.
Most people: “I see a rabbit!” “No it’s a duck!”
Me: I see both...
Doesn't everyone? I tjought it was about which one you see first
@@jankisi AGHHHH
First there is a mountain, then there is no mountain, then there is
I grew up on Uranus
I grew up *in* Uranus
I bet you are stinky
Sometimes when I look at my popcorn ceiling, I can either see the indents as indents or a bumped out. Yet another of these awesome illusions!
“If you didn’t grow up on earth, please let me know,” - I didn’t grow up on Earth. But thankfully, this video was clear enough for me to understand your basic human problems, and relate it to mine elsewhere. Thank you.
Dat stick figure Henry in the end tho. O.O
He reminds me of Rick and Morty's Anatomy Park...
Man, this video is driving us UP and DOWN
end
PenArt this comment is underrated
Awesome animation.
1:50 took me a full minute of light physics in my brain, and to see both as concave and convex. DAMMM
„SKLLSHHH!“ 4:00
I just realize that these videos are made with markers and not on a whiteboard
It could be possible that from 3rd dimension, 4D objects appears 2D.
From 2nd dimension, 3D objects appear 1D. In general, from Nth dimension, N+1 dimension objects appear N-1 dimension.
It could be related to definition of dimension and/or sensors.
So we could be getting confused by images.
That's not true. Imagine extruding a curve with some thickness into 3D space. If you're a point in the plane, you will be able to see where the curve is "backward" from you in space (because you have depth perception, a feature of 2D). So it will appear to you as a two dimensional object rather than a straight line drawn across a single axis. I think you're confusing "object" with the specific case of polyhedra composed of straight line segments. And even in the polyhedra case: if you're a point on the plane inscribed *inside* the base of a polyhedra, you will be able to deduce what kind of polygon the base is by rotating 360 degrees and counting up vertices. So many 3D objects can and do appear 2D from a point perspective in 2D.
Plus, by your thinking, all 2D objects would also appear 1D from a point perspective in the plane. There's nothing special about 3D, so you've erred both in your statement and the uniqueness of its implication. I.e.: from the perspective of a point in 3D, 3D objects appear as 3D (barring cases where one axis is obscured / optical illusions), so even if your formula were uniformly correct it wouldn't apply to higher N.
@@otherwords1375 Its not about watching 3D objects with 2D eyes with depth perception in 3D world.
If we draw a 3D curve with thickness and I am 2D object myself, then to see that curve, it will first have to be projected on my 2D plane. Even if it gets projected right before me, I will see only front part of projection and not what's behind it. So it will appear 1D. That's, from 2D, 3D objects appearing as 1D.
@@jaydeepvipradas8606 I don't understand what you're saying. I'm not saying that you can see the thickness itself (the surface area), only that you can see *that it is curved* and thereby that it is not a straight line but varies along with a y axis. I.e., that is two dimensional. You don't get curves in one-dimensional space, only two dimensions, so you don't have to see what's "behind it," just the fact that it bends. Which, again, the eyes of a purely 2D point see. This conception of "depth perception" makes no reference to 3D information.
Also, see my polyhedra critique. If you are a 2D point inside a cross-section of a 3D polyhedra, you can rotate 360 degrees -- again, a capacity you have because you are in 2D space -- and count up vertices, determining that the object you are seeing is indeed 2D.
I'll admit my metaphor confusing. I should have clarified that what I mean by 2D "depth perception" isn't the kind of 3D depth perception where you judge the distance between points on a plane by looking "above" them in the Z direction (or by looking at their shadows, contingent on a 2D projection of 3D information.) If you have a point A on the plane, you can clearly draw a line through that point and two other points B and C. If AB is longer than AC, A will "see" point B as further away. This is very simple 2D point perspective and what I meant by "depth." I.e., I just mean an intuitive notion distance, which one would certainly have in 2D space. So my argument stands.
@@otherwords1375 Pure 2D object can still perceive depth of whatever is projected before it, it need not see just straight line, this is similar to humans having depth perception in 3D world. But it is still 1D of 3D, because 2D object can not see things that are projected beyond most front side of projection.
Rotation and orientation will allow seeing different views over time. But at a single moment in time, 2D would be seeing 1D.
2D object can have intelligence to construct multi-dimensional object by continuous rotations and various orientations, but without intelligence, 2D would purely see 3D as 1D.
Your point of view could be correct, but this is my point of view as of now.
the lights on the ISS just blew my mind, never thought about that :O
I was born on the sun
Flight The Goat React's Oh that is why ur black
You must be a ghost.
From like the instant you started existing.
@@bunny_0056 -racist- *BURNNN!!*
I was on the moon
I _was_ the sun...
... before it was cool.
Please don't use that adobe shit.
We love your drawing.
I like to see Henry using different animations, but the appearance of his iconic stick figure should still retain. I see that the proportions of his figure here is different (larger head, slightly shorter arms, and textures different from UnPuntoCircular's version). We'll see if he'll retain those details.
If he can make his animated stuff indistinguishable from the drawn stuff I'm fine with it tho.
Most of the video is hand drawn, he just used adobe to illustrate the convex and concavity thing.
chill.
Osimmac, in the sponsored stuff at the end (3:30) he talks about learning Adobe Character Animator.
Vishal Jangid I would call it shit, but I am sure we can all agree that his stick figures are unique to his channel.
So cool!!!
Is this related to scary faces being lit from below? Because it's "unnatural"?
The illusion is very real, but in most of your beginning examples, I got it correct, not because my brain doesn't have the same biases, but because one version of the "mountain or valley" made more sense in context. Like, the Grand Canyon from above makes a lot more sense geographically if it cuts into the earth rather than the other way around. The Mars picture clearly had craters that made the valleys make more sense in context. And the Snake Creek sign makes far more sense that the letters are cut into the wood, not only because it would be easier to make that way, but also because the texture of the wood reveals the location of the light source anyway, just like the Mars craters do.
"if your not in earth, please let me know"
Astronauts: am I a joke to you?
nice bro
No...I was never born on earth
Moved here when I was 9 months old
@Katelyn Wu nice
Excellent.
2:53 The sun is sometimes in the north in the northern hemisphere. In particular, it's in the north when rising or setting in the temperate (non-tropic, non-polar) regions (such as the continental United States as shown in the video) and it's closer to midsummer than midwinter. The sun is always to the south at noon.
I am not from Earth...
I am from my mother
... Mother Earth?
( #CouldntResist )
mother russia
And i am from the city of England
That's what my Nigerian teacher always says when I ask him 'Where are you from'?
Good man, he is.
I am from Metal
I fear no man.
But that...thing
3:30
it scares me
3:20 So there IS a reason why characters in cartoons flip their maps upside down.
Thanks for putting Akershus/Oslo
so we had a second eye for depth perception but then it still lies to us
Depth perception won't help you very much when you're looking at a picture
Clearly this means we need a third eye!
@@RonDe675 Stereoscopic picture viewing will capitalize on the (for most people) second eye to help provide a better grasp of depth. However, it is not as common, because for EVERY photo, a second one must be taken at a set distance from the first one at the same time, and then EVERY person who wants to (and can) use both eyes needs special viewing technology that will properly display those twinned pictures.
0:51 i didn’t grow up on earth!
😂
"If you didn't grow up on earth, please let me know"
Me :
I really enjoyed the blues clues bass as u were drawing
Like you channel name, I still don't know if "minute" refers to the unit of time or the expression of size.
B. Hagedash If you aren't joking, its time.
I would say both. It's "science in a minute (or four)" and it's "bite-sized science".
He does pronounce it in the same way the unit of time is pronounced, though.
Cool, I'm a new viewer so I haven't heard him say his channel name in a vid yet. Or I just missed it.
dunno why, but Im seeing just bumps, no holes, just bumps everywhere.
0:10
The 'SNAKE CR' one is easy.
The GRAINS of the wood are still there, it's clearly burned into the wood.
(Plus I have a little bit of experience with woodburning so I know how it looks.)
"hey henry here"
The character: *is a stickman*
Me: oh my god it's henry stickmin
Amoooooooohhhh nnnnng us !!! !!!!!!!
LMAO I thought the same thing
ohkeh
0:51
-I didn't grow up on Earth-
Just kidding XD
Yee Tee ur kidding?? omg i had no idea like for a sec there i thought u where form mars no joke
MochYee lel XD ur so randem and funny I didn't get the joke until you said JK X🅱️ dttdghdttjrdtjrdyjtyjdrtjdt
Lit.
When i look it it first its either one way or the other, but then a look at it slightly to the left, i look left and right to left to right and it almost flickers between mountain or valley
This reminds me of that drawing tool on the *3DS* camera where you could draw convex and concave stuff and use 3D to see it