Can You Perceive Acceleration?
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- Опубліковано 28 тра 2011
- How do our eyes scan across a landscape? Contrary to popular belief, they don't scan smoothly across a scene, they observe a series of images. The eye is capable of panning smoothly however. If something moves in your field of view, your eyes track it smoothly. This has an important effect on our perception of motion. It makes it more difficult to see when objects are accelerating since the eye tracks all motion quite smoothly.
I watch his videos because it inspires me to pick up women using science. Lately I've been using a forklift.
And if you drive very fast they can't get off.
is the forklift needed because of the singular mass, or collective mass of these women?
Hopefully the later.
A forklift? Bro you must be collecting feminists.
try chloroform. its much more efficient! but.. you have to pick them up yourself.
Driving me nuts that I can't smoothly scan a scene...
same here its annoying lol.
Move your head and neck, not your eyes.
@@ongbonga9025 actually you can move your eyes smoothly if you go out of focus, the scene gets blurry but you can move them without jumping because there is no detail or reference point. Same if you're in the dark, or in front of a white wall
@@thesteaksaignant Man that was amazing. I succefully saw without breaks, without focussing!
@@thesteaksaignant yes I was abour to say this. Just pretend a bug flew by your face. Just don't do a distance focus, almost go cross eye - but not that far. Then scan side ways.
the lion in the grass was the greatest explanation for anything. ever.
Always the lions in the savanna.. hahaha
reachthroughreality I think he used the same analogy for why we can instantly count up to four, but have to count individual items for higher numbers. Is there one lion or three lions? That makes a difference. Are there 99 or 100 lions? You're fucked either way.
😂 😂 😂
Was that in this video?
@@mythrin I think you might have to rewatch it...
Dammit, I never noticed my scanning wasn't smooth, now I'm going to be CONSTANTLY AWARE OF IT.
Haha, same here!
Wow I've known most of my life
NoriMori Keep your eyes constant and move you head smoothly..
+NoriMori i noticed it when i was really young, because i actually noticed it myself it got me interested and i can never stop seeing it now. really annoying
Unless you force your eyes out of focus, even if you move your neck, your eyes will keep locking onto things in the distance, and they will still jump around.
Cool we have a built in lock on mode, like an Apache helicopter.
ROTFL.
Apache helicopters are the only real gender :D
Jake Long no I identify as a green fidget spinner!
@@jarchive4267 Green ones are the most common.... Basic bitch.
sucks we dont have a laser guided missile to make good use of that though
Derek has that thing where he picks up the accents of the people he's talking to.
Isak Bohman I know, just pointing it out because I'm bad with accents :P
Doesn't always work though, if it's too obvious, it can be perceived as insulting.
reinux I also do it alot without even noticing.
armoredp or if it's not accurate lol
I think hes australian born, he might just be used to talking like that
he's jumping from accent to accent. intriguing lol
Xander521 HAHAH ikr he sounds so brit in one part thn American in the other lol
Yeah I noticed that and it was cute! But in more recent videos it's gone.
@@smilefenn4813 more like Aussie and Canadian accents
@@someguy89 Yeah sounds like shifting between west coast Canadian and Aussie accents. I've noticed people shift into the accent of the people they're talking to if it's similar to an accent they've had in the past.
He's from Vancouver but he lived in Australia
This always frustrated me when I was younger. I would look out a car window and want to focus on the constantly moving tree line but I couldn't because my eyes would only focus on one tree and follow that one unless I unfocussed or switched trees.
Hye from France, I'm 25, I relate to that. I wonder how many million people have had that same frustrating experience :-)
Eh whaaaaat
Saaame gosh experiences are so similar everywhere
same lol, But I did it by trying hard. I was able to do it. And Hi on this comment after 7 years.
Derek: *uploads video in 2011*
UA-cam in 2011: "not in recommended"
UA-cam in 2012: "no, still not in recommended"
UA-cam in 2013: "not in recommended still"
UA-cam in 2014: "not yet"
UA-cam in 2015: "still not yet"
UA-cam in 2016: "nah, still not time"
UA-cam in 2017: "not quite yet"
UA-cam in 2018: "still not now"
UA-cam in 2019: "it's time"
Greatest comment in 2019 :))
Have there even been recommendations back in 2011?
@@razvanmantu That's amazing, considering it has already been made infinite times in 2019.
Must be a lot of us here right now
Your accent came out in this one! I love it :)
Plot Twist: He actually does this show to have a reason to talk to females.
what a lad
his wife, and kids might disagree.
He saids : "I want you to guys watch it", so he may not even know what's female x)
@@orbinya2885 what??
The only teo comments in the last week were bots
i love the moving your head while looking at yourself in the mirror trick
Tristan Miller i love the moving your head from mars, to Sirius trick...
great album :D
i love flying whales from mars to sirius
i like turtles
Which does a good job of explaining why took so long to understand that gravity is an acceleration.
Stephen Powell gravity is a force
@@imonkalam5419 Gravity is the curvature of spacetime ;)
@@HerrVonWelt a force that was caused by curvature of space time that makes things accelerate
@@ishouldhidemynamelmao345 Exactly, thanks :)
@@HerrVonWelt its an acceleration guys. Weight is the force
Kinda sad that UA-cam stopped being quality content like this and they now have to recommend us 8 year old videos
Wait what? Derek uploads consistently till this day.. There are much more quality content now than 8 years ago..
You just have to find them, i recommend Vsauce, Ding! And smarter everyday.
This is called survivor bias. You just remember about the quality content that was made in the past and does not consider all the shitty content that was made in the past. The truth is there has always been qood and shitty videos. Detek has made a video on this topic. Check it out
Hashil Muhammed eyy I like the sciency psychological approach
When I first saw the title, I thought he would be talking about perceiving ourselves accelerating, and of course we can do that easily. It might not (probably does not) compute mentally, as far as making projections of our position, but we definitely know we are accelerating, because that's the only motion that applies force against our bodies.
Not exactly true. You cannot feel acceleration directly. You can only feel surface-acting forces(I don't know if this is the correct term in English) affecting your body, like objects pushing/pulling against each other. You cannot directly feel mass/volume acting forces, like gravity.
That's why you feel different when standing on your feet and on your arms. The ground is pushing against your base, and each of your cells are pushing against those surrounding them. If you sit down or lay down, the directions of these interactions changes, and feel different. You do not accelerate, yet you feel some of the forces affecting you and how they change after you move.
If you were in a free fall without atmosphere(like skydiving on the Moon - bad idea...), the only force affecting you would be gravity. No mater how you arrange yourself relative to the Moon, changing the direction of gravity and therefore acceleration direction on your body, you wouldn't feel anything changing. Gravity would affect all your cells in the same way and direction, therefore it wouldn't create any "additional" forces acting between them which could be measured.
m4cksfx
Actually you can feel acceleration. That's how the vestibular system works, using the inner movement of a fluid (endolymph) in the semicircular canals, utricle and sacule of your inner ear. Allowing you to directly perceive linear acceleration and rotational movements.
Dildios, Destroyer of Lies Close, but you seem to be missing a point here: this system can only work if its parts are moving relative to each other and pushing against each other, otherwise there is no force to "work" anything which can be registered by your system. If you accelerate(or don't accelerate at all) in any way which causes a force to affect a specific area of your body instead of all of it at the same time(for example by standing still, being kicked by someone, jumping, sitting in an accelerating car), the force is kind of "passed on" to other areas of your body. Your feet push against your ankles, which then also push against your legs(and back at the feet as well, but this is obvious), your pelvis and so on, and at some point the "tubes" push against the fluid, which is how you perceive acceleration. The gravity is pulling the fluid down, while the canals push against it to keep it from seeping down into the ground.
In a true freefall(meaning no air drag), the only force affecting you is the gravity, which is almost exactly the same and acting directly on all parts of your body. There is nothing to cause this "serial push" between various body parts other than due to, I don't know, blood pressure and stuff, so there is no relatively strong force acting between the fluid and the "tubes", which would cause you to feel acceleration.
m4cksfx
Oh..true. I stand corrected.
(2 years late, but hey...)
Actually, some models of general relativity take free-fall as the inertial reference, so, from that perspective, normally, most of the human race is accelerating upwards at almost ten meters per second per second, and in free-fall there's not really any acceleration to sense.
It's still true in those models that a non-gravitational force that acted equally on every part of your body would be undetectable without observing something outside the volume of uniform effect.
Your accent changes when you talk to Aussies :)
Their have British accents not Australian
I totally noticed it though when he said watch it
Which is why the beach looks so bloody cold.
I spotted it when he said "smooth" hahah
I did the same thing though. I went to summer camp when i was a kid, young out with an irish kid for 8 weeks. I came back home with the accent.
These are British tourists
Ask any of my friends the tennis ball question, you will receive "9.8"
Probably just the number, too.
Jaden CM is it moving? Nine-point-eight
Jaden CM you're wrong😂 it's 9.8 m/s/s that wasn't 10 meters
austin longfield non-sequitur, good job.
9.80665 djees
Damn it!! i need to sleep!!! but i cant stop watching these videos =P
TheDawg475 LOL!!!! YOU"RE 2 FUNNY MAN!!!! HAHAHAHAHAHAHAHA!!!! AHAHAHAHAHAHAHA!
OMFG I'M DYING!!!!! HAHAHAHAHAHAHAHA!!!!
@@softwarebobby think so
Have you slept yet..
@thebottlemusician yes there is a positive side - we track smoothly those things that are moving, which makes us well coordinated and able to track prey and avoid predators. It just has the funny side effect of obscuring the laws of physics.
i have a question, not a science question but a very valid one, did you end up getting that brunette's number?
+Matt Mcginnis ...
+Matt Mcginnis Depends on what you mean by "science".
+Matt Mcginnis She's like 16
+philophos she's at least 21
+philophos age is just a number bro
*reads description*
Ik,r!? When i was like 5, i was SO ANNOYED that i couldn't move my eyes slowly without looking at something moving!
I also discoverd when I was like 9 years old that when people watch out of car window their eyes move and shake.
Sorry my english is so suck are u my secret other me? same thing here..
Defocus your eyes so everything is blurry then turn your head. It doesn't make it easy, but it makes it a little easier than otherwise.
One of the ways to test vision in an uncooperative or cognitively impaired patient is to use a length of tape with vertical lines spaced regularly every centimeter along it's length. You hold the tape in front of the person's eyes, and pull the tape laterally across the visual field so the vertical lines move laterally in the person's visual field. This creates an effect similar to what you see when you're in a car looking out the side window, watching the trees move across your visual field. While pulling the tape, you look closely at the subject's eyes for saccadic motion, an involuntary jerky lateral motion that is only present if the person can see. This test works even in infants, it's a very reliable sign that cannot be suppressed.
*Important tip* : If you need to scan a room or scene or anything in detail, then do so by moving your eyes from right to left.
Our eyes tend to skim things from left to right due to our reading habits of skimming through text so we don't see much detail when moving eyes from left to right.
whoa this is even more interesting!
arabic
0:36 beautiful eyes...
***** You're such a buzz kill... Although I've been on this buzz for quite a while now, thank you...
This was the first Veritasium video i watched. I immediately felt in love with the channel because the video answered a question that i had since i was a kid.
Brunette girl focused more on Derek than on his experiments lmao
Love the way you used the term "Lock on"
I don't get it.
Me neither
not everything is a joke
Also sorry for being three years late
@jamesahibbard This is a good point - but I've tried it with people at many different angles, close up and far away and they still see it as moving with constant velocity. Therefore I think the perception is more a result of our smooth tracking eyes.
1:00 That gave me a good idea. If you imagine an object moving and track it you can move your eyes smoothly.
+Shaheer Syed That sounds really interesting!
+Shaheer Syed But then you can't take in any of the information of the landscape because you're concentrating on following your imaginary object
Jonas Hamill I tried it and you can
+Shaheer Syed I thought the same thing, you can also follow a line of objects with your eyes, concentrating in one after another, works pretty well too.
I can't, when I focus on the imaginary object the rest gets motion blur and I'm unable to actually see the scenery.
Actually I am not convinced with the falling ball example, I think if you watch something accelerating for a longer time you can tell if it accelerates or it slows down
Holy cow, I’ve been watching these videos for 8 years!
we cant see a small object, like a ball, accelerate because our eyes are not focused on the background clearly enough.
He does a good job of balancing teaching people and showing that they're wrong but without making them feel stupid.
I think the whole point of his experiment that day was to get them back into his flat. I mean, that's what I would have been after..
I noticed how fake smooth 1st-person camera pans looked since forever and read a long time ago how the eye jumps from one interesting object to the next. Apparently when choosing Lara Croft's appearance in the newer games, the studio did a test where they had viewers look at certain faces with certain facial features and recorded which features the eyes were mostly attracted to - in other words, Lara is scientifically hot :) (Also, Meghan Farquhar)
I never realized that when moving our eyes across a stationary object, they actually move in increments!
I've been a subscriber for 8 years now and it surprises me that there are still videos that I haven't watched.
How could they possibly believe the ball was moving at a constant velocity? Haven't they taking a basic physics course in school?
I think most people just totally shut away the science they learn in school, because most people just hate it and find it so confusing. I think if he'd really made them think, they would have remembered the acceleration due to gravity, but they didn't even bother thinking.
My heart Accelerated just by watching those pretty eyes
Damn get out much?
Yeah right? Derek is so handsome!
s i m p ?
You bat for the other team?
Who did you hire for that killer (no pun intended) animation?
I watched a documentary on sight several years ago that actually mentioned all these things he said. Awesome.
I'm pretty sure you adopted an accent there for minute. Like multiple times.
this guys like "bitches will talk to me about anything cuz i got my swag beard'
I was very upset for many months in class 11 when i studied all this.... The things i was observeing from childhood were seemed to be different than written in books... Thanks a lot. I wish i have seen this video 8 years ago
1. Nice excuse to chat to girls.
2. Love it when you let the girls speak in the end. Respect!
Could someone please explain to me the point of this video ? I still don't understand why not perceiving acceleration is a good thing
Our eye only see frame to frame to prevent us from motion sickness.
Thats not true. You don't get motion sickness if your eyes track something that moves relative to you. And that includes both possibilities: The object your eyes track move while you are standing still (your brain doesn't sense any source of motion like moving legs or something) as well as you moving and the object standing still (your brain does notice a source of motion, like walking).
In fact, motion sickness is unrelated to the way our eyes are always tracking something.
Your eyes are tracking all the time because it makes it easy to follow things while they our you are moving. It allows you to walk to something (like an edible plant) and to observe something moving (like a dangerous predator). Therefore, humans with eyes that track object had higher chances of survival in the stone age.
On the other hand, when a human moves, there are always multiple signals that go to the brain. First, most of the scene the eyes see is static. So if the static is moving, that means you are moving, not the rest of the world. Second, if you are moving, you feel how the movement is created. For example, you feel your legs walking. However, in modern times there are cases that break that combination of signals. For exampe in a car. You see the static moving, but don't feel that much of the movement. You are sitting still in your chair. Another example is an IMAX theater. You see the static (the landscape in the movie) moving, while you are sitting still in your chair.
In both cases your brain gets the same signals (static moves but you dont move). However, in the first case you are in fact moving and in the second you dont. That confuses our brain and sometimes creates motion sickness.
Oznerol256
It seems to me that you need to watch a certain Brainiac episode...
/watch?v=Hts-nbvC8TM&t=6m57s
HaphazardDisastard Okay, i watched it. Nothing surprising there. Well maybe the thing about the driver. Thats because he has control over the whole thing.
You can tell when he lived in Australia his accent slightly changed. The way he says "fast" and "quite" are clear indication of that.
I like how he was giving a good explanation to them but then when they had no idea what he meant he dumbed it down for them.
Back when he had a thicker Australia accent. It was already thinning out here.
"constant" ...
I'm crying rn
Thanks for the intel, had no idea about this kind of stuff. Will remember it for future use.
i like how you can look at something, and moveyour head around in any direction and your eyes can still smoothly track the object. just look at a word, then turn your head back and forth. it feels creepy
When i was small i exactly though the sane question.
I thought I was the only one that has noticed this.
same
+TheBrutalSledgehammer OMG me too
Everyone has eyes, so it stands to reason most people notice this but don't mention or think about it much because they assume everyone else knows about it.
Cortster
Not everyone can see.
vleesevlons Not everyone has legs either, but we say humans have legs. Stop being cute.
I noticed this when I was looking around at things, I'm glad I understood everything he said in the video through my own experience
I've thought about this soo many times!! while in a car, reading, or scanning landscapes. I'm so happy I'm not the only one who thinks this 😂
Lmao.. anyone who took basic physics would know that the ball accelerates when dropped.
the point of the video was not to show that the ball accelerates but rather to show that your brain does not perceive this acceleration very well.
kamikazejo Well, yes I understand the point very well. I am just trying to say if most people were asked this question, they would say the ball is accelerating. Unless people don't know, then of course they would respond based on their judgment, in this case, what they saw. So I guess what I am trying to say is maybe a better demonstration should be used instead? Idk.
xihai luo I understand what you mean. It appears that instead of being based on information learned prior to the demonstration, the people chose to rely on what their senses could interpret. My question is why these people don't have a better preconceived notion about basic laws of physics, especially something as important as acceleration? This video was a one-two punch for me: 1) Your senses are deceiving when trying to perceive your surroundings 2) Education is beginning to lack globally.
I guess this is as fitting a quote as any, but it appears that there's more to it than meets the eye :)
Among other things, I learned from this video that her eyes are really beautiful
+Satie TheTutor her tits too lol
Did not realised this before, thanks a lot man
I think the reason we don't notice the acceleration is due partly by the fact the object is moving farther away.For example when we see a jet plane at high
altitude it looks like its moving slowly across the sky when in fact is traveling just a little slower than the speed of sound..
If that same plane flew just a few feet above our heads we could not
imagine anything could move that fast.
He's starting to get an accent and it is beyond adorable.
The only thing smooth out there is you brother. Hey what this ladies...
who has the best joke about him using this to pick up girls?
These old Derek videos are marvellous
Been watching your videos for years and just noticed an Australian twang in your accent
I think he might have chosen them to stare into their eyes.
His accent is so much stronger in this video.
By the title of the video I thought that it was about the feeling of being accelerated.
I think you can only feel accelerated if the acceleration is not uniform across your body.
Great. Now I'll be constantly trying to view things without the jitter motion for the next month!
HHHmm I like the lady with the brown hair. Wonder how I can contact her?
Ask the police for her number when you get your one phone call.
I thought the same thing. She looked very nice in the near shot when he was filming her eyes
@@martinjager6914 I was most impressed by dem titties.
2:37 "Would you say its speed was constant or do you think its speed was changing?"
I would have replied with something like this(should be a system of differential equations taking into account the gravity based on mass and distance and laminar air resistance):
df = (dx = v, dv = a+c_w/2*rho*A*v^2, da = G*m*M/r^2)'
So basicly, since the speed is the integral of the gravitational force minus the air resistence and does not equal zero, the speed must change. d(>.
Not only overkill, but highly irrelevant, since he asked what did they see, not what the ball actually did.
And you made a mistake too, the integral of a force (with respect to time) is momentum, not velocity
/r/iamverysmart
r/Iamverysmart
Wow you really picked up some of the Australian accent in this video. I began to perceive it in a few others but this is the strongest one yet.
One more amazing fact is that every time that your eyes jump, like when the girls follow the ball, your brain do not record what you see in-between start and stop. That means that you in fact lose time every time your eyes jump from one spot to another!
heha he intentionally picked women for experiment , a man would have said the ball is accelerating (no offence ladies :p)
This made me think about art and how our eyes "flow" over it; directional forces affect our perception of art, even being able to create a sense of movement in something still.
Smart to pick 2 people who wouldn't be smart enough to know that the ball is accelerating even though it started from 0
I always knew about this because at night if there's a radio tower or something with a blinking red light, and you move your eyes, the red dot will skip from place to place rather than moving slowly. I always wondered what fps our eyes are seeing at..
that was strange because no mater how much i tried to look at things in another way it was like my eyes didn't want to do it. it was like i had little to no control of my eye movement, or perceptions of acceleration. lol good video
just imagine there is plane flying above the horizon and you can pan smoothly.
I figured this concept out as a child looking out the car window driving down the highway.
Even when the eyes appear to track smoothly, theyre still jumping, but at a much higher frequency or frame rate. Also we can clearly detect acceleration because we can catch accelerating objects.
I never thought that pursuit movement can decrease the perception of acceleration.
First time I see this video and I'm a subscriber since... forever.
I haven't watched this video yet, just the first. The eye definitely jumps from point to point. I know this because I used to travel on a bus a lot with friends and collegues and if you watch someones eyes as they look out the window at the scenery passing them you can see their eyes jump back and forth incredibly quickly. Its so wierd because when you yourself do it, it doesn't feel like your eyes are moving at all. It feels like your eyes are stationary and the scenery is just moving past you.
en.wikipedia.org/wiki/Saccade
I can perceive the acceleration of UA-cam algorithm kicking in and recommending this video to more and more people freaking 8 years after it was made.
I play airsoft in dense forest alot and I've been thinking about this. You can scan the area smoothly without locking-on to something. It takes a bit of training, but It's easier to spot details like other player's camouflage or silhouette. Also, you can learn to aim with each your left and right eye with same efficiency. Also it needs a bit of training.
Watching this in 2019, not realizing it's from 2011, going, "Wow, Derek is letting his Aussie accent show... wait how old is this video and why haven't I seen it before?"
Move your eyes to the far left, unfocus, and pan your head right. Behold! A blurred, out of focus, but very smooth view change!
I have been aware for years of the fact that my eyes can (based purely on my perception) move smoothly from left to right, but not from right to left. I think this is just because I learned to read left-to-right text when I was younger.
The only thing those girls got out of this lesson was that their eyes move smoothly when watching something, but they stop and go when they are not. That's it.
I love that you picked up an Australian accent in this video. :P I haven't noticed it in any other video of yours.
Another possible reason as to why the women perceived the ball's velocity as constant could be due to the relatively constant angular velocity of their heads as they looked down to follow the ball. When the ball is dropped, it is near their heads and as it falls and accelerates, it moves further and further away from their heads, requiring a less drastic change of the angle of observation compared to the increase in speed of the ball.
I actually tried this way before watching this video. Frustrating how I really tried to catch everything from a stationary object while moving. Thanks btw.
So is there anyway for the human eye to scan smoothly like if you "trained" yourself to do it? Or is it just something that's not possible do you think?
By the way I love your videos, they make me wish I were still in my physics classes!
With the tennis ball test. I see a problem with his analysis. It's that the ball is accelerating downward which means the important information the eye gets is that the ball will appear to get smaller rather than move away faster.
The location of the women when he drops the ball and the ball’s initial height alters how they would see the acceleration. If the ball were to move at a constant speed, it would appear to slow down because the angle they would change their eyes would decrease. But since it accelerates, the angle changing is closer to constant, so the ball appears to move constant to the women
Very rare but some people can do the “smooth tracking” without moving objects, they can smoothly scan a scene
That first girl, when the camera zoomed in on her eyes, I was immediately in love. Could make a video about what's going on there.
if you drop the ball and let it bounce back up to eye level and fall again, it's much easier to note that the ball slows down and then picks up speed as it falls
They always seem so much more interested than when I explain it.
i don't know if i'm the only one who can do this, but when i move my eyes from right to left, i can will it to move smoothly without locking on to anything, but it's harder to do it left to right.