How Every Movie & Video Game Tricks Your Brain

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Movies. Video games. KZbin videos. All of them work because we accidentally figured out a way to fool your brain’s visual processing system, and you don’t even know it’s happening. In this video, I talk to neuroscientist David Eagleman about the secret illusions that make the moving picture possible.
Thank you to The Slow-Mo Guys for sharing some incredible footage with us. Here are the full videos:
• How a TV Works in Slow...
• How a 3D TV works in S...
• Arcade Machines look W...
References and sources:
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[@besmart]

Did this video make you question reality a little? 😂 Find me on Instagram and Twitter and tell me what you thought of the video! @DrJoeHanson @okaytobesmart

[@starsandsus3725]

I still like your old intro and name

[@gotnobitchesTwT]

@@starsandsus3725 yes Joe here

[@brentkoops9581]

an excellent argument for intelligent design. There's no way humans "evolved" out of the sea...

[@dissonanceparadiddle]

@@starsandsus3725 ok I thought I was doing insane

[@1134_BAVANESH]

seems our whole life is an illusion 🙄."colours" don't exist, they're merely a perception of the vibration of the electromagnetic field by our eye cells.So much for "real"ity 😂which is unfortunately just a perception of our senses😌

[@moongirl786]

Our brains edit out "camera shake" too. Our eyes, heads, and whole bodies are constantly moving, but we don't perceive that in our picture of the world. Just try flicking your eyes from place to place really quick and you'll see there's a split second edit that takes place :)

[@lauribleu7558]

Wish my brain did that. Shaky cam gives me vertigo so intense I want to vomit.

[@DracarmenWinterspring]

@@lauribleu7558 I don't think that's what OP meant - lots of people get motion sickness from shaky cam in movies, but most don't get sick from simply walking around, even though our head and eyes bob around similarly to how a shaky cam bobs around, so they should both be capturing unstabilized "video". But your brain knows which way your head is bobbing and can compensate to "edit out" the shaky cam effect, while when you're watching video from a camera that isn't moving the way you expect, you can get motion sickness.

[@lauribleu7558]

@@DracarmenWinterspring mostly making a joke, but i do get horribly motion sick when walking about or just moving my head while having vertigo attacks attacks.

[@RichConnerGMN]

input lag

[@royotl3635]

Great input from the OP! Check out a cool article in the Smithsonian magazine called "Our Eyes Are Always Darting Around" (no link because of KZbin), the answer is really cool and complex. This "editing out" works due to the fact that our visual system can only "see" the world in full "resolution" at a very limited range (it's called foveal vision), hence our eyes need to constantly move to "scan" the environment in quick, short and jerky movements called the saccades. Like the article says, our brain probably intentionally suppresses the visual signals reaching our retinas during saccades, and then fills up the gaps to make it logically continuous. It's the "making up the story" mechanism from the video, the brain is like a video editor. And things can get omitted or even blended together, if they happen fast enough during the saccades. You can treat this mechanisms as a natural "shutter" of the visual system, dividing a blurry flow of signals into conceivable slices/frames of reality, and then fusing them together. Visual perception is weird.

[@MoritzvonSchweinitz]

The "postdiction" thing, or the whole notion how the brain creates stories that make sense to it in it's current state is also why memory is very, very malleable and changeable, and not at all like a hard drive or a video recorder. That's one of the reasons some scientist are advocating to reduce the importance of eye witness testimony in the courtroom. It's way less exact and precise than we would all like to think.

[@KryptonKr]

I think eye witness testimony is still useful BUT only if the events is still fresh because the reason why memories changes is because of time obviously and also other eye witnesses story. That’s why it’s better for these witnesses not to compare notes at all and should be interviewed separately

[@jonathanodude6660]

@@KryptonKr the questions you ask as well as the tone and vocabulary used can alter the memories of an eye witness. to continue using them there should be a standard set of non-emotionally charged questions that you can ask in a low stress environment so they dont question their memories and theyre as accurate as possible.

[@jonathanodude6660]

the postdiction phenomenon is not the same as memory editing.

[@gildedbear5355]

My favorite visual illusion is the one that happens with clocks. When you glance at a clock the second hand will seem to pause for a longer a time than the seconds that follow if you keep looking at the clock. It's caused by your brain postdicting (love the word) what the second hand was doing while your eyes were rotating to look at it. Oh, also, your brain postdicts over the blurred movements of your eyes.

[@Danspy501st]

I always found it funny to look at a clock and look at the second hand, as to where it feels like it staying still for more then a second, before it move. After that, it just move for what feels like a second

[@kennethstudstill]

@@osmosisjones4912 I cannot confidently interpret the context and meaning of your comment.

[@Escher99]

The effect is known as "Saccadic masking". I've noticed the same effect makes car wheels "stop" spinning if you glance away and then back. Very odd effect because otherwise you can't really tell what they look like while they're spinning.

[@AnyoneCanSee]

@@kennethstudstill - I think it's a failed Haiku.

[@beactivebehappy9894]

Yes it's like, our brAin wants a beat drop like tune: tak...tak...tak..tak.takta.ta.takarsgdkdkh 😅

[@Syrupandwaffles]

Making animations is so fun, just seeing a still drawing come to life is amazing

[@AceSpadeThePikachu]

I've always been fascinated by the concept of how our movies would be seen by beings, like certain animals or even extraterrestrials that process visual information slightly differently. Would they even be able to visually comprehend a movie, or would it appear as a garbled mess to them?

[@djfrashatch]

I've wondered the same thing

[@royotl3635]

For the most part, it would depend on their flicker fusion threshold rate (like it was stated in the video, when the flicker becomes a continuous movement/light), it's basically the refresh rate or Hz. Insects for example have generally a much higher "refresh rate" in their eyes than we do, up to 300Hz, so looking at the TV (not OLED) they would see a boring slide show with static images. They basically see in slow-motion. Dogs I think have a flicker fusion around 70-80 Hz, so the 60 Hz TV would flicker fast for them. And of course the colors would be way off, yellow, blue and gray. With movies in lower frame rates it would be just worse. There are some studies about this topic, and generally "how animals see the world" is a super cool subject that we are constantly updating our knowledge about. Check out mantis shrimp vision, it's absolutely bonkers.

[@lindareed8265]

Apparently cats and dogs approve. So many of them watch screens!

[@jaredlapierre1304]

The same way flip book animation looks to us, probably.

[@oanaalexia]

kzbin.info/www/bejne/jWSsmpecZcyji7c

[@EyesOfByes]

3:40 You should probably put a "flashing images" warning in this one, just in case

[@co2_os]

Yeah thought so too, it's a bit extreme

[@amongdoomers9464]

Why warning? I didn't get it

[@woenel]

@@amongdoomers9464 flashing images might cause seizure to some individuals specially the ones with epilepsy.

[@amongdoomers9464]

@@woenel Oh , I didn't know that , thanks!

[@freshoutofcrabs]

@@amongdoomers9464 In addition to seizures, it can also trigger migraines.

[@anita4609]

I guess our brain filling in the blanks to create continuity in what we see is also pretty important for blinking without it feeling disruptive

[@kushchopra4300]

What if the brain is constructing all reality all the time

[@semaj_5022]

@@kushchopra4300 It is, in a way. Your brain is constantly taking all of the sensory information your body receives and using it to construct your reality. It is doing this nonstop at all times.

[@PeterFreese]

One of my favorite visual experiments relates to our blindness during saccades, and how this can be demonstrated by 1) looking at our left then right then left eyes in a mirror and seeing no motion in our eyes, and 2) then using our phones in selfie mode to do the same thing, in which the very small delay allows us to observe the saccades.

[@allensandven0]

My great grandfather was blind from birth, and my mother and grandmother along with documents to support some rather amazing claims have left me fascinated but still looking for explanations . For example he learned to compose sheet music in brail sometime on his early adulthood, could. Identify who or what just walked into a space or room ? And shingled the roof of his home alone in his late 70’s , how is this possible without ever seeing anything of your surroundings for reference and did he visualize his surroundings in 3 dimensions color and textures or scale . It just seems like it would be so frightening and empty at the same time ! If you could dive into how this works it would be a great experience

[@tashmoore3825]

Be Smart did an episode on how blind humans can also use echolocation. It may help you figure this out.

[@marmac83]

you don't need eyesight to identify who just walked into a room...

[@allensandven0]

@@marmac83 really? If there’s no one talking and let’s say it was in a public space

[@marmac83]

@@allensandven0 The sound of their steps, the subtle sounds of movements... If you know somebody, chances are you will be able to identify them even in a pretty crowded room without seeing them. On the other hand, stop moving the goalposts. The original statement was "in a space/ room," which implies a confined area, not a public space. I wouldn't believe you if you said your blind relative identified a friend at the other side of Woodstock '99

[@k.c1126]

I think blind from birth might be less frightening and empty, because one never had the use of that sense to begin with. The other senses would work to provide the brain with information in ways that we sighted people might not ever be able to grasp. It sounds like your great-grandfather's story would be fascinating.

[@CupOfNoodlesMusic]

I can't remember if it was mentioned in a prior Be Smart episode, but this reminds me of the nose and toe touch test. If you touch your nose and your toe at the same time, in your head you feel like the sensations happen at the same time, but the time that it takes for those signals to get from your nose to your brain and your toe to your brain is different. It's like our brains are constantly dealing with the delay in our nervous system to keep everything feeling consistent when in reality, its not. Living in the past is what we are exceptional at I guess haha

[@Pfhorrest]

I can't remember if this is an original idea of my own or something I read about once, but I think that postdiction like this is how dreams work. Your brain is shuffling through a bunch of mental images and you're perceiving them one after another but this postdicting, narrative-writing part of your brain then goes "wait I was on the subway platform then I was eating a banana sundae right afterward how is this possible oh it must be because there's an ice cream parlor *inside* the subway car" and BAM weird dream scenario postdictively concocted to explain the connection between two unrelated things.

[@MrSpasticdancer]

thats a damn interesting point

[@golgothasterrified]

I should be sleeping instead of watching this, but science never sleeps!

[@yrm1594]

Maybe, but science also says sleeping 8 hours at night is good for you.

[@bloodypigeon]

@@yrm1594 He don't need sleep, he needs answers!

[@nathanhass]

I suffer from migraines with Aura, which affects how the brain processes vision. Interestingly it can mess with some of these processes in addition to the other phenomena that occur. For example around the time of an attack and also during what I call a "migraine scare" I can see some light fixtures appear to rapidly flicker that usually appear as a solid steady light.

[@imme6954]

Does everything get louder and smell stronger, too?

[@nathanhass]

@Im Me I mean I could make a whole list of other bizarre neurological symptoms I get with them, migraines are horrible. I was just commenting on the light stuff relating to what he's talking about.

[@GabyHache]

I can confirm. That happens to me when I’m hungover 😢 I’m glad to see someone else suffers from the same. I went to the dr once and told him that and he dismissed it saying it wasn’t possible.

[@PaulPaulPaulson]

There's still room for at least one more video on the topic. How do the cells in your eye and the nerves to the brain work? Do they fire at a constant rate? How is the signal encoded? Can a single nerve cell signal an analog value, or just a pulse with no amplitude associated to the signal? Does the frequency of it firing correspond to e.g. the amount of light? Is each visual cell connected to exactly one nerve cell? At which rate are they firing? Are the cells synchronized or is each firing at its own speed? Is there one receiving cell in our brain for each visual cell? If so, how are they arranged? Are they arranged in a 2d pattern corresponding to the image? Do color and brightness signal from the cones and rods end up in the same arrangement as in the eye or do they end up in different parts? How does a brain cell know if it is connected to a rod or a blue/green/red rod? How does it grow in an embryo? Do the eyes and the brain start connected and grow apart or are are the nerves in between grow and connect after the eye and brain forms? Which of these things are known to science and which aren't yet? Do animal eyes and brains work the same?

[@dr.jamesolack8504]

My question is…..how do you sleep at night??

[@moongirl786]

You sir, speak my language. Teachers rarely have satisfactory answers to my questions. I assume you've read up on the four primary interactions, or forces, and the theory of everything? My question is, what the heck is electric charge? If electrons and protons are just carriers of that charge, with a higher quantity of charged electrons than protons in an ion being transcribed as a negative charge and vice versa, what is this mysterious charge they are carrying? All I've been able to find so far is vague lines that its something to do with photons... Now unfortunately, I was unable to study science in university due to a learning disability in math, but I am gifted in linguistic intelligence, so if someone explains these concepts in plain English (no equations) I understand it fine. I also have an interest in linguistic anthropology, that is, how people use words and languages to express concepts, and the evolution of terminology, particularly in academic disciplines, which is often convoluted and speaking at cross purposes, for example, what we now call "elements" because it was thought at one time that they could be divided no smaller, are actually not the smallest units of matter. Neither are atoms, which at one time were also considered to be such, so the language we use is very confusing as it has not always been updated

[@punkdigerati]

That's many many videos, and years of research. Some of those questions are answerable as of now, and some are not.

[@ifunny05]

@@moongirl786 Its been like 8 years since my last physic class, but iirc charge is just a property of particles like for example conductivity is a property of matter, as you said, the qty of protons and electrons decide the overall charge of the particles and depending on if they are positive or negative charged they react to electric currents. I.e a positive charged particle will be forced into a positive charged current and vice versa. It is also a property that defines how a particle will intercat when exposed to magnetic fields but I dont remember too much now. Hope I helped a little, but recommend searching for multiple sources in the internet to get a better understanding :)

[@kindlin]

@@moongirl786 I'm no physics wiz myself, but let me give this a try. Asking what _are_ photons and the electric charge is like asking what _is_ being wet with water. It literally is that which you just defined it as. I know that answer, at first glance, can seem meaningless and nonsensical, but that's what happens when you ask what _is_ a fundamental aspect of our very universe. I think of electric charge as basically gravity, but way stronger (a _lot_ stronger, but that's for a different reply). Things with mass have gravity, things that interact with the electromagnetic field have charge and generate and follow electric and magnetic potentials. The really great thing about modern theoretical physics is how connected everything is, mathematically, once you introduce and subsequently break a few symmetries. The underlying nature of our entire universe is fundamentally described by a simple statement such as: SU(3)xSU(2)xU(1). What a wonderful time we live in to even be able to imagine such things.

[@Barnardrab]

That's interesting at 8:25. At first, the dots appear arbitrary, but when moving, a walking figure is present. It shows that our minds piece together indivisible features into an abstraction, which shortcuts to more concrete features. This principle could be useful for image recognition software.

[@salsal435]

Thank you for having David Eagleman on this video, he's one of my favorite scientist

[@fruition21]

His book, Incognito, is awesome

[@jacobkrueger1022]

I think my dyslexia changed my view from what you expected. I visualized the walking dot man before they were played rapidly, I didn't assume the dots were chasing because I had already noticed the red wasn't moving and the blue was just shaking. The changing red and blue dot also didn't really work, I just thought of two separate entities.

[@gregtasi]

Omg same :O

[@Eldorado1239]

I don't have dyslexia but I think the red/blue dot was a very poor example. Didn't see it the way he described it at all. If a sparrow flies into a tree and an eagle flies out on the other side, I'd never assume the bird transformed... and besides, the distance was too big to assume it has moved.

[@lucidmoses]

Broken? I'd say brilliant. It sure seems like a lot of this evolved out of the need to stitch together sight and sound. It even explains how you can focus on a single person voice at a party of hundreds. i.e. the temporal information.

[@nathanfish1998]

Speak for yourself about that party thing. I can't even really concentrate on a single person speaking with 30 people around. To be fair though, I have adhd so concentration isn't exactly my strength

[@oO0catty0Oo]

@@nathanfish1998 I was going to say the same. However I'm not fooled by the invisible gorilla thing (selective attention experiment) because I can't pay attention to one thing long enough to miss the gorilla walking through.

[@ChicagoMel23]

It was created, didn’t evolve

[@lucidmoses]

@@ChicagoMel23 Lol, I'd ask you to prove that assertion but we both know you don't have any evidence at all. That plus the effort you must be using in order to avoid learning means there is not much point in this conversation, I'll bow out.

[@lucidmoses]

@@nathanfish1998 being able to make out single voices is a different thing then not getting distracted by other voices. But if indeed you can't isolate voices at all you would be in a rather small group (other then hearing impaired people)

[@adebayoglover]

I paused, stared, rewind, slowed down, and did all sorts of things on this video. I completely struggled to understand how messed up reality has been with our eyes and brain scamming us all the way. Great video from PBS

[@kn0bhe4d]

Interesting video, but wanted to say that I couldn't finish it since the flickering bits that came on randomly and stayed on far longer than I'd have thought they would gave me a headache.

[@maromania7]

We are no longer assured of our ability to be smart, we are given the command.

[@resourceress7]

Agreed. It's a weird title change.

[@superieur11407]

I only noticed they changed the channel name when you pointed it out.

[@leogama3422]

The times changed.

[@Roguefem76]

I was wondering about that myself. I think I prefer the old name.

[@ariesearthdragon]

@@resourceress7 I only started watching this channel about 3 months ago. What was it originally called?

[@emmanuelkoech8564]

So weird. I've actually experienced the flickering light mostly in class where I would notice the light flickering, but only when I'm not looking at it. When I'm lost in thought maybe. But as soon as I looked to check, it wasn't flickering anymore. I thought I had a superpower but yet So fascinating to learn how that comes to be.. Another incident is my easiest way to slow down a video on KZbin where I hold down the Spacebar. The Audio would break down but yet still the Video would remain smooth. I guess the Auditory reception didn't evolve that way. So weird!

[@richardschatz9992]

Just finished watching the "When is Now" video, which ties right in with this one, and now my already tenuous grasp on reality is shattered completely. Fie on you, Be Smart!

[@lovenightcraler]

this feels almost like my first class of animation ! We had a small history on how the eye worked and we had to create one of the two toys you see in this video ! But there is also things that I feel like should have been talked as well that were left out. As much as your brain create a story, there is a limit to how much it link up 2 different images. If a sequence of pictures, let's take a bouncing ball as exemple, where the main subject ( the ball ) keeps changing size between each pictures, your brain will decide that it is not the same ball and not read the sequence as one motion, but as many pictures. I think it could have been fun to have a animator explain how animation works and relating it with the science behind it !

[@toonedin]

Corridor Crew! With Hank sitting in the middle of their famous sofa!?

[@royotl3635]

Hey, as a film/media scholar I feel an urge for a small correction - thaumatrope isn't the sole, or even a direct reason why movies, video games, and especially animations exist. Let's focus on movies and the elements of their apparatus - a projecting device (projector), an image carrier (film strip) and the apparent motion. Every one of those elements existed hundreds or thousands of years before the first movies, and was used in different media before. Movies are basically a combination of all of those, possible to achieve because of the smooth development and upgrade in different technologies. The optical principle necessary for projecting any image is the camera obscura, it's usage goes back to ancient or even PALEOLITHIC times (check out the paleo-camera hypothesis, it's cool), but the proper description is associated with Alhazen, who you have mentioned. The projector understood as a device, not as an optical principle, is also a camera obscura, but contained in a small wooden box with mirrors and lenses. It goes back to Italy around the 16th century. And from there, literally EVERY part used in first movie projectors (besides the film strip) was developed during 300-years-long reign of magic lanterns (from 1659), today a completely forgotten medium. They have developed a plethora of new and interesting visual techniques, involving many forms of apparent motion. Movie projector is literally a magic lantern with a different image carrier, and they have used many different ones, so it's not a revolutionary step. And magic lantern is literally a box-camera-obscura with glass slides as image carriers. They are heavily related. The various forms of illusion of movement have a long and separate history, involving media such as panoramas in the 17th century (check out dioramas by Daguerre and eidophusikon, both super interesting), shadow theaters (earliest traces around the 1st millenium BC), and cave paintings (up to 30 000 years BC) as you mentioned. Around 1800s, photography added a new and better image carrier to the whole mix, so a new way to register and save reality, or it's visual trace (freaking "light-drawing", right?). Not a big leap from photography to movies, you only need a fast enough succession of images, the details weren't hard to figure out. Check out chronophotography. My point is - the development of movies and animations (or any media, really) was a smooth gradual process, rather than big leaps made by individual devices or individual people. The thaumatrope is not in the center of this process, not even close, it is a byproduct of more general notions and the zeitgeist at the moment. We need to think about stuff like that diachronically, because it's more impressive and cool this way. And more correct. Nice video though! :)

[@daemonace5910]

In magic tricks one of my favorite concepts is a concept called image retention. It's interesting to learn from this video the concept is very possibly a combination of apparent motion and persistence of vision, or sometimes one of the two. Stay curious

[@bakr6405]

Thank you very much, I will never be able to scroll on my phone or watch videos normally again. Because once you see it, you cannot unsee it.

[@carmamd]

I’m a retired M.D., and enjoyed this immensely!! Great presentation!

[@eliscanfield3913]

I get something like that when I hear words. Because I'm a bit hearing impaired, I miss sounds in peoples' words all the time. My brain will insert something, often something *really* wrong, lol. Then I have to go back and figure out what it was likely to have been.

[@MattNeufy]

What a fascinating video, this is one of the few times I’ve subbed after a single video, before even checking out the channel let alone watching another video! Looking forward to watching dozens more like this!

[@OmateYayami]

Brain's great at confabulation. The real relevation is that it's doing this interpolation to lots of stuff. Vision, but even still images - fills in blind spots, but also memories.

[@aviraj4587]

Whoa calm down shakespeare

[@MerkhVision]

Its action on memories might be the most significant and paradigm shifting part

[@JTRumpet491]

Should there be a strobing/flashing light warning on this video? Some of the alternating images might cause issues for the photosensitive

[@flatline8580]

This is a great explanation of what film makers have known for a century. And it is also exactly why we have made machines to see/interpret the things we can not. Also: blind people, deaf people, etc. The whole topic is a wormhole!

[@TheHypogriphQc]

Once again, very good and informative video. Thanks for the great content!

[@Diogofrn]

This is the most interesting video I've seen on this channel in a long time. And that's saying something. Well Done! I quite enjoyed it 😊

[@KarlGBergman]

Excellent. We grew up with movie projectors in the house and I was always fascinated by the mechanisms inside. (movies, too) Nice North By Northwest ref, btw 😆 Thanks for sharing!

[@davidking3931]

I love getting a number for the refresh rate of our eyes. I have always been curious of what that number is for our favorite pets; cats, dogs birds, etc. And what does that mean for them when we watch videos like this together. Do they actually see the same thing, or is it a jumbled mess?

[@ag135i]

That's why blind people are so sharp and reactive to sound and touch as compared to people with vision because their brain doesn't get fooled by the visuals.

[@ironassbrown]

This video reinforces my view on subjective experience. When referring to human perception I would typically say that the world around us is real but that our perception and experience of it is a simulation built in our mind based off of the sensory input that the brain receives. I would invoke the confabulatory nature of our minds to explain why this second-hand experience feels as if it is first-hand and in real-time, the idea of "post-diction" sums it up much more nicely, I'm thankful for that description. I look at it as a kind of reverse form of simulation theory; The world is real, but we do live in a simulation that is happening individually in each of our minds. It feels painfully obvious to me that this is the correct view, but in the last fifteen years or so I am not sure I have persuaded a single person even as I have sharpened my narrative with practice. edit: great video btw.

[@SkLLzDaTkLLs]

Best video I've seen from a while from you Joe. Great job :)

[@SporkleBM]

Yeah it did make me question reality. Just a tiny bit though. For the most part this was cool to learn about :)

[@MrBigTimeChiller]

Conscience projection is an interesting concept too! Let’s say you’re watching an emotional Pixar movie (😢) you are so caught up in the story that most of your senses stop being perceived. This is how jumpscares in horror games work. You get hyper focused and forget your other senses exist until Freddy Fazbear is shouting in your face.

[@jasondomican1991]

I found this video amazing bro! I genuinely had such a good time watching this one!!! I hope your feeling better from covid bro 🤜❤️🤛

[@TimpossibleOne]

Your brain is in constant remembrance mode. The image of light lingering longer than it actually has is your brain remembering what it just saw by layering memory from instance to instance. That's what gives the illusion of motion to still images.

[@CasadeLindquist]

This video is great, but it only covers the tip of the iceberg of where things go wrong with our perception. For maximum-level reality-crisis I think it's also important to consider that unless you are actively in the middle of experiencing something (looking at it, listening to it, etc), what we are actually experiencing is an imperfect memory of what happened! Our brains do not record the raw data collected from our senses, rather our brains record what we “expect” to have seen or heard. This means our reality is the result of a subconscious game of “telephone” where various brain regions are passing information around and they are all editing the information along the way. By the time your brain finishes seeing something, storing it into memory, and then recalling that image from memory it has already had many chances to alter the memory to match what we “expect” to have experienced. This explains everything from why magic tricks work, to why we’ve all had the experience where we hear someone say the wrong word and then when we tell them they said the wrong word they respond with, “No I didn’t, I said it right, you just heard the wrong word.” Neither of you is lying, your brains just crafted 2 different realities. Which means one of you is living in a reality that isn’t actually real and unless there is a recording of the conversation there’s no way for you to know if your reality is a lie. But it’s fine. I’m fine. Everything is fine. Look at the Wikipedia page for “Eyewitness testimony” to read more about how terrible human brains are at remembering things correctly.

[@royotl3635]

Super interesting!

[@HughLeFitness]

Hope you are recovering well!

[@BE-rn4px]

Hey thank you for sharing this right as I’m just getting into stop motion as a hobby! This was super interesting and very helpful :)

[@korg47237]

The name sake of this channel has changed from a comforting statement to a direct command.

[@j.m.6733]

Great video! Please do put a trigger warning for flashing videos. It can really make a difference to some people :)

[@francoislacombe9071]

0:10 You are showing us a picture of Sir John Herschel, William's son, a great astronomer in his own right. Also, William died in 1822, so it is more likely that the Herschel attending that party was Sir John.

[@rossholst5315]

I would say that it is not just objects that move quickly fool our brain into perceiving motion. You also have processes that move very slowly that we perceive as stationary. In wound care I often recommend drawing an outline of the red inflamed tissues surrounding a healing wound. Sometimes an infection can be present but growing so slowly that the wound appears to be static or the same as it was yesterday. Without a boundary to use for a reference point. Visually detecting slow moving processes can be difficult. But all motion depends on having some cue by which a comparison can be made showing to show how objects are “moving” to some point of reference. When the different body systems are sending conflicting information to our brain, the body can get very disoriented. Like vertigo and the fluid in the ear combined with visual cues on a horizon. But just as equally the absence of differentiable cues can cause disorientation, like flying through clouds, or being lost in the complete darkness of a cave.

[@shaorandra]

Something I didnt expect to see: Swiss coins :D Illusions are fascinating! I learnt a lot from this video

[@carsanwitt]

made me pause and skip back when I saw it!

[@Zoldgameclips]

This is a great video as usual, but could a warning be edited in at the beginning for viewers with photosensitivity, because there's a lot of flashing images in this video!

[@moongirl786]

I like the irony of that

[@beactivebehappy9894]

@@moongirl786 more like tautology, any video in itself is flashing images (just fast enough that it's imperceptible)

[@joshuayammer1994]

Recently I’ve been noticing flashing stuff like that messes with my eyes. This video definitely hurt my eyes.. feels like they get super strained.

[@Zoldgameclips]

@@beactivebehappy9894 or instead of making jokes we could care about people possibly having dangerous seizures while trying to watch this video that has no warning for those with epilepsy or general photosensitivity

[@chialingchew1857]

Glad you are all OK. Keep it up with all those great videos!

[@celester.812]

I loved this video!! We use so many things and don’t even know how they work. I always feel like, damn, somebody is smart enough to know how smart phones work, like they are smart enough to actually invent them… I don’t even understand how you can take a photo and save it on your gallery…. This should be a series , explaining how our everyday gadgets actually work!

[@enadegheeghaghe6369]

The truth is that there are no photos in your gallery. In fact you do not have a gallery. The information captured by the camera is converted into a series of 1s and 0s and its this binary code that is saved in the phone or computer memory. Your phone or computer have no clue what a photo is in the real sense, all they know are huge amounts of binary code (series of numbers consisting of 0 and 1)

[@sylviahoffman9440]

Awesome email and descriptions of the visual processes!

[@ninal309]

So much interesting information, it's fascinating to trace back how technology evolved.. from toys

[@Idaastrand]

I always use this to ensure myself in uncomfortable situations, like getting a shot (I'm really scared of needles)... i tell myself that by the time i see the needle going in to my arm, real life me has already finished taking the shot since I'm just experiencing the lag in my brain 😂 i know it isn't that far behind irl, but it soothes me to think that the actual thing and my experience of it only overlaps for a short time if that makes sense 🤷🏼‍♀️

[@chrisklugh]

This is so true with human perception 16:40. Everything that you are, what know, what you think you know, is just fragments of different things that your brain puts together afterwards. How many of these things is different from person to person, but whatever it is, it makes up our believe. We are a Product of our Environment. What environmental stimulation, be it education, is how we perceive the world. It is also control of that perception that can control you. Marketing in a nutshell capitalizes on this very thing. And those in Power know this too. They will do just about anything to ensure what you know serves them. What you know is carefully constructed and not necessarily true at all. But you believe.

[@zm959]

this was one of the most entertaining and educational things i've seen in a while wow tnx man :)

[@aestaetic07]

3:40 FLASHING LIGHTS!! for the light sensitive people, there are a few parts of this video with long continuous flashing lights and to the channel managers, please put a warning beforehand or in the title of the video! thank you :)

[@griffmonster9504]

I’m with you! I was watching this at night on an OLED

[@DriantX]

Seriously, I don't suffer from epilepsy or anything like that, still had to pause the video for a few seconds to breathe.

[@aestaetic07]

@@DriantX SAME..

[@ItsBarmanji]

Cant thank u much whenever you upload its like a cute science experience that fills my brain with curiosity and happiness

[@oneshot478]

Videos like this are why I love this channel!

[@devincreislerstudios]

I had a spinning disc toy growing up! No wonder I like to make videos all the time.

[@akjvoksn]

I just love watching videos from this channel, please keep in making his high quality content!!

[@rafaelleyson8337]

Nice video!!! Daily refresh of curiosity and knowledge.

[@nicksnisar4135]

Wow, what a great story! Really makes me think over my reality and what is actually happening in my brain. This means that actually we never live in the present moment. Everything that we feel already happened a moment ago

[@BUKHAREE]

Glad to see you’re doing better now

[@subodhbhosale4205]

When you get to be Smart after you feel okay to be smart. Joe it's Be Smart🤨🤨🤨

[@subodhbhosale4205]

I don't trust you hacker

[@lucasmoreira3237]

Amazing video. Thank you.

[@sudhirsingh1552]

Thanks a lot gentlemen for this information & such lucid explaination. Personally, I only knew about 5% of the whole that too superficially. I am grateful. 🙏🙏

[@Danspy501st]

So our eyes is like an intel agency that collects everything they see in a detail manner, and our brain is the top that needs to figure out what to do with said information and just choose to ignore about half of it. So basically our body is like a nation

[@momo7gato]

Lol

[@royotl3635]

Actually, detailed, full-resolution vision is only around 2 degrees of our eye range, it's called "foveal vision". So we must move our eyes a lot to see the whole picture in detail, and the brain kinda blends it all together. It does not ignore half of it, but ignores the blurry motion made during those scanning movements (saccades), in order not to confuse us.

[@JeffNeelzebub]

Interesting. The reason why this works is because evolution has hard coded the principle of conservation of energy and momentum into our brains. This works quite well for hunter-gatherers on the savannah, but the reason we are tricked is because sequential still images is not something that we encounter in nature.

[@Tropicallyglutenfree]

Love Dr. David Eagleman. He is fascinated and fascinating.

[@LEDewey_MD]

Great video! (And I hope you''re feeling better!)

[@Aaron-ni2eu]

In addition to this, I would love to know if anyone anywhere has studied why we have no 'edge' to our vision? It's just so strange that the brain can literally just blend our ability to perceive our sight even though our eyesight has an outer boundary, and we can't comprehend anything past the edge either! Further more does blindness give that person this no perception of vision or blackness??

[@akakabira]

They don't percieve anything Not even black or darkness It's like not knowing a sense like there are magnetic sensors in birds brain to help with directions during migration but we don't have that(we have but it's not used) that doesn't mean we always sense north or south or anything also that brain percieves a change of vision that's why even if you are concentrating at a point, your pupil is constantly moving to emulate that movement and if blind people can't see (yes that's what blind means 🤣) then there isn't any change in vision so it slowly fades out of sense

[@thelelanatorlol3978]

@@akakabira I think the real answer is just that our vision is so blurry near the edges that we simply can't tell where the edge of our vision lies.

[@Appletank8]

I had someone describe blindness to me as trying to see something behind your head. There's nothing _to_ see.

[@IroAppe]

@@thelelanatorlol3978 Yes, if I look straight ahead and just focus on my edges, it's just a very blurry mess over there. And then nothing.

[@IroAppe]

Now that I did focus on the edges of my sight, I am astonished how wide my view really is. It goes almost 180°! Didn't know that. Of course the image data at that angles is garbage, but yes, now I see how we can definitely sense if someone opens the door or something happens all the way over there. Also I can see how animals that have their eyes on the sides of their head, can almost sense 360°. PPS: Now that I've looked it up, it's amazing :D Apparently we perceive 95° to the left, and 95° to the right. Together that's an angle of 190°, even slightly over the 180°! It's just that the overlap of both eyes is only 60° to the left and 60° to the right. So with both eyes together we perceive 120°.

[@niiii_niiii]

I love you Joe x

[@niiii_niiii]

@@IJ-49 hurrrahhhh!!!!!❤️❤️❤️❤️

[@niiii_niiii]

@@IJ-49 and our smart minds 😍😍😍😍

[@d0dge407]

As a videogame developer, it's pretty mind boggling to see what moving picture started as, All the work I do for my games would have never been possible without that dinner, very interesting to think about.

[@phionella7]

Love the snark from the globe Looks like you're feeling better Joe, I hope you're well.

[@resourceress7]

I highly recommend that you add a warning at the beginning that there will be flickering and flashing lights. People with photosensitive epilepsy could have a seizure if they watch this video.

[@XD2021]

He missed the part where That's his problem

[@XD2021]

@@samarnadra he missed the part where That's his problem

[@heliumnetworking5103]

@@XD2021 when they get sued for inducing a seizier cqusing ohysical harm. yeah man it will be their problem I reckon but cool dude

[@officialpowerofbanana]

@@heliumnetworking5103 I just did some searching and I only found 1 case where that resulted in legal consequences, and the perpetrator was doing it intentionally in a harassing manner (sending multiple tweets of flashing lights to the epileptic recipient). It's probably a good idea to have a warning, but I wouldn't expect any legal consequences if it's not done.

[@officialpowerofbanana]

@@samarnadra yeah it makes sense to do it. I just don't think the legal argument is the most convincing, since there are too few successful instances of charges and fines for that to be a credible threat. I think a simple request is sufficient, and then those who require that can go elsewhere if it doesn't happen.

[@tuxuhds6955]

6:39 I like how it's "Arab mathematician" for the non westerner and then actual names, like real people, for the western philosophers. He just invented the Pinhole Camera and was a founder in fields like optics and psychology. Ibn al-Haytham, it's not even hard to pronounce. Please show some respect towards non-white people but at least naming them.

[@angelusmendez5084]

Outstanding... Thanks!

[@Raison_d-etre]

Be Smart is my favorite KZbin channel.

[@TorpidN1ghtmare]

*Will I get a like for being here on time for once??*

[@lakrinmex8132]

Why did you change from "it is ok to be smart" to "be smart" ? So it isn't ok to be smart but be smart anyways?

[@gooffoog7686]

Imo, the name ‘its ok to be smart’ probably has to do with being nerdy isn’t bad, but nowadays there is so much misinformation (or lack of basic information in general) that changing the name to ‘be smart’ might be to show the importance of good education …or it could just be just to change it up a bit

[@ari-ds8ui]

this is so great i have been thinking a lot about this topic lately.

[@thiccanimethighs7589]

Great video as always!

[@BradleyWest435]

I COULDN'T AGREE THAT YOU CHANGED THE NAME TO "Be Smart"

[@L1mbo]

Please include a seizure warning ⚠️

[@markrowland1366]

The coloured disc, when spun appears as white. A sparkler, fireworks, moved in low light, amazed.

[@Walkingcedar2006]

9:20. This reminds me of a comment the Scotty character made in JJ Abrams' first Star Trek movie (2009), when Leonard Nimoy's Spock showed Simon Pegg's Scotty how to calculate transport at warp. Scotty's response was, "Huh! It never occurred to me that space is the thing that's moving."

[@bigsmoke4]

Is it not ok to be smart anymore :(

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[@maravilore1910]

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[@diegoalmeida9611]

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[@whatsapp-2217]

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[@nataliepinheiro6457]

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[@MrBinthestudio]

I love the arcing sound with the Flamingo sign!

[@PrincessSachiko]

i love optical illusions, so i loved this video of course!! very interesting to think about the science behind why our vision works te way it does. and another thing i love is old machines like the ones in the timeline starting at 2:19. for some reason, old machines like that are fascinating to me. i wish i could play with all those machines1

[@zarinloosli5338]

This would not be an ethical experiment, but: If you strapped a VR headset on a baby, feeding them a view of the real world, with their brain develop the ability to detect these flickers? In other words, is this motion inferring circuitry hard coded into our dna, or does it just naturally develop?

[@Looo0007]

have you ever seen a bad lights? those that strobes just a tad too slow? (usually cheap LEDs) like, you know something is wrong but when you try to look at it, it isn't there. and you'll only find it when you look away, keeping the light source on the peripheral view.

[@lindareed8265]

The spinning disc at the end totally worked!!!!

[@Borisam]

Extremely well explained video!!!!

[@mentiefeio]

I live how a change of thumbnail and title, made these video much more interesting ✌😇