It's like this fragment of "The Little Prince" when he draws an elephant in a snake and adults say it's a hat. You can put white sheet and when people say "Oh, you dressed as a ghost" you'll say: "Wrong, it's retina protein" :D
This is one of your better videos. You managed to cram a great deal of one semester of biochemistry and physiology into little over 10 minutes, and it's still informative and not complicated. Excellent work, Steve.
A good argument against 'irreducible' complexity is that we should absolutely expect extremely intricate multi -step processes to be the norm with evolution by natural selection
Something I have only recently learned about myself, is that I probably am affected by "visual snow". I thought it was everyone's experience, to at all times see a continuous field of tiny red, green, and blue dots, until I said something to my wife about it, and she hadn't the slightest idea of what I was talking about. The little colorful dots are almost overwhelming in the dark; I don't really see "black" at night, just red, green, and blue. In the day, I see quite normally, though if I sort of stop focusing on what I'm looking at, I can tell that it's really just the RGB dots.
you are presenting theese rather complex themes very simple, so an electrical engineer like me, that does'nt know much about biology could understand how this here works kkep the good work up! :D
Fantastic stuff! I always wondered about this. However - the brain is not electrical - it is chemo-electrical .. or electro-chemical .. there's a cycle .. you can't just call it electrical - and a lot of mistakes are made if you think like that. Fantastic - you clearly get what non-linearity means .. so I also assume you know whta l;ocal minima are? If you do, then you will understand how the visual system is adaptive? Now .. consider this - the switched layers of adaptive signal processing are not one-way - there is always a feedback from each level to the next and back - and it operates as exclusive-or-gates to sharpen signal .. based on experience!!! How wonderful! That is what "pins and needles" is when you disrupt your receptor network by laying on it while you are asleep . the next layer keeps polling the previous for instruction about what to suppress .. "pins and needles" is no more than your polling layers getting no reply - and it happens at the frequency of the polling .. I learned this by studying my wife who had(has) MS and tracking her experiential evidence from a known spinal lesion ,, so go figure? Adaptive switching is a seriously important insight .. it means we can train ourselves to see other spectrae .. like if there was a need for that .. your graph of human spectral response is bogus .. if you go look, you will find that graph wildly deviates from person to person .. the graph does not show an error-spread .. so it's probably narrow and wrong. Well , that's my prediction from the standpoint of networks, chaos and how non-linearity creates adaptive switching .. happy to be shot down in flames?
Your explanations are so amazing! In almost every single one of your videos, you express a concept that isn't explained all that often in a simple, humorous, and surprisingly informative fashion. There is no unnecessary simplification, it follows the science beautifully, and everything is put together just right. This channel is one of my favorites on all of UA-cam and I never hesitate to share your new videos after watching them. I hope you go right to the very top.
Well, there's always simplification. For example, why does light cause the molecule to switch from cis to trans? It has to do with a radical mechanism of isomerization. Why does the molecule's shape and its interaction with proteins change the frequencies it absorbs? That has to do with the wavefunction of the electrons and delocalization/resonance. I think Steve is really good at choosing precisely the right things to leave out to tell a coherent story, and that makes him a very good educator. He'll rise to the same prominence as Veritasium or VSauce if UA-cam let him.
Hey there Mr. Mould. Nice vid! So, uh... I don't know how to break it to you so I'll just go ahead and say it... I think your studio is haunted. yep like with ghosts and the like
There are some snakes that got heat vision. They got cells that work similar to a microbolometer pixel below their noses. It's just 6 pixels but the anatomy allows them to combine the signal greatly and locate something to eat in the darkness. It's likely responsive to 6-12micron wavelengths. Which almost fit into LWIR thermal cameras. There is a great paper with low of images that show a modified therma imaging camera to represent what said snake and "see". It's a difficult evolutionary questions because our own skin can sense heat by a different method but we never developed a optical centrum for it. It's likely due to the properties of liquids found in our body.. water does not transmit infrared radiation in those wavelengths, but blocks it. Water has been a vital step into forming the eye - homogenously. The snakes sensors operate more like a pinhole camera. I am a thermal imaging enthusiast and for me that is one of the most interesting topics of biology.
that kinda reminds me of how they use antenna arrays and some crazy triangulation like inference to image a black hole. would that be a reasonable analogy?
@@andrewaronson3364 interferometry does work by combining wavelengths of a synthetic aperture. It can't be done in a body, so the analogy falls apart. It's more like yours ears. Where a a few sensors can give a full 'picture' because of the specific geometry and location between just two.
I'm guessing (as I have no knowledge of biology) that your brain wouldn't mind active low signals, it's like that 'you'll never know if other people experience color the same way' thing, so I wonder if it'd actually work if we simply removed the not gates or if they have some more important functionality as well.
Had the same thought. N then had a small bout of horror when it expanded to a 7 step process. Active low, invert, bit of a byte swap to get your pixel map, endian swap for dsp, dsp, nor matrix with some other channels, endian swap for interpreter, slice stream to fill framebuffer. Its a heck of a kludge, but does seem to work pretty good. (Just a fantasy imagery of whats goin on, ive no idea. But sounds about right) Makes my brain hurt.
Now consider conditional Boolean Math? Not not? Not how much not to not?? Minsky was a good go-to-guy about the topology of Boolean functions - specially in the realm of network adaptation. Fun stuff! He smashed neural net ideology by proving that NN cannot do exclusive or .. that was a breakthrough, but things developed from that . you can get Exor with enough topological layers - and specially when there is channel suppression from a feedback .. (complex back-prop) Last time I saw Minsky .. he was hiding his modular cognitive model to talk about how shaking-hands killed more people than guns. We are entering a time where the science of context becomes important. We will ultimately learn the absolute limits of atomic molecular switching - the blind-spot of the atom. But .. quantum reality shows a way forward. A Way that we have barely set foot upon, and learned that human feet are not good for this path? Think on that brother? Your insight will be valuable.
Fun fact: besides the iterative nature of evolution leading to all the weird and wonderful steps in a chemical reaction chain, another reason for the multiple steps is the activation energy required for each one. If the goal was to switch from molecule 1 straight to molecule 5, there isn't always enough energy available to raise into the new stable configuration, without more costly processes like raising the body temperature. Thanks for the video, you are master of describing complex topics in simple terms!
In many cases, the different elements in the signal transduction chain also have other uses as amplifiers or points where regulators can affect the signal. I don't know whether it's true for this specific one, but it's often the case in these kinds of signal transduction chains in a cell.
@@i9114 I don't know about him, but I do think. Evolution makes sense even if we consider it a dumb luck. Think about it. Because dumb luck needs to be lucky, it took millions of years for our eyes to be like that, for millions of dumb mistakes to occur in our ancestors DNA that just so happen to make something just a little better. (But don't forget about the insane majority of mistakes that led to death and disease of individuals. Thats why we only see the lucky ones, the unlucky are dead). Also, because dumb luck is dumb, our eyes are flawfull. The biggest flaw: Our retina is inverted. The photoreceptors are at the back and not at the front of it. That makes so that the light has to pass trough a layer of tissue, scattering it, and making our vision an inaccurate depiction of the light that enters our eyes. This is also why we have a blind spot. The nerves that come out of these cells need to turn around and go through a hole (the blind spot) in the retina to get to the brain. There are a lot of other problems. You should search about the origins of the human eye and also about its flaws, it is really interesting and I think that it makes much, much sense. Evolution is pretty half-assed if you think about it, you just have to give it some time to take something out of it... like... "millions of years" time... but the result is great... I mean.... it works... sometimes
The most amazing part of all this is that everything explained here happens in a matter of milliseconds, and has probably repeated something like millions of times while I was watching this. Being pretty much flawless, at least not in ways I can perceive. In moments like this that my awe for evolution is the greatest. Thanks Steve, I love what you do.
I'm pretty sure none of these processes come even close to flawless, it's all in just how robust to these aberrations the entire systems we're made up of are
@@AsmageddonPrince yeah, I know there's guaranteed degeneration through time, it's a given since no process is perfect. However I think it's impressive for this system to last 10 minutes, or years with little to no perceiving of flaws. Sometimes it's amazing to imagine how someone can live for years without even noticing that their body could be tearing apart from malfunction. This extremely complex and not pre designed system is way more resilient than I can ever imagine.
@@metametodo Believe me, it is't evolution. Self assembling atoms can not account for the ability to see or to have vision.This is a deliberate act of design. Evolution can not make atoms, self assemble, into living systems.
@@h7opolo not to be rude, but are you hearing impaired by chance? i am, so lip reading is kind of important to me. I missed the mistake you caught though, and I forgive Steve.
Hey Steve Great Video! We learned all of this in Medical school and the crazy thing is that in the retina not only the detection of light but also the processing of this information happen. You have different Horizontal cells which become activated by the photoreceptor cells and inhibit surrounding photoreceptor cells to create contrast. That is for example why dark areas seem on the edge to white areas much darker than being surrounded by dark areas. Fun fact: Most of the Proteins you have mentioned are reused by the body in different locations. cGMP in the nose and tongue for senses. Transducin which belongs to the family of G-Proteins are used in the Sympathicus(fight and flight) to increase your heart rate, constrict your Arteries,...
Well yes, but this biochemistry is the first step and the brain won't get anything faster than this step allows. It uses various processing tricks to fill the gaps somehow, but this can't be done forever. ;)
Hi Steve! Very nice video, as always. Just a little precision concerning what you explained around 11:31, the colour matching functions x(λ), y(λ), z(λ) are representations of the chromatic response of the observer, they don't exactly correspond to an amount of blue, green and red light. Thanks for all your work !
Kind of. Kind of not. Red/Green colour blindness isn't the only possible type; there are others. (Every combination you can think of in fact). It's just that Red/Green is the most common - and yes, that's because of how close together they are. Colour blindness is generally caused by a defect in one or more cones. This either means one of the cone types is less sensitive to light than it should be, is missing entirely, or has a defective protein that doesn't do it's job properly. All of these have the effect of rendering one part of the colour range non-functional, or near enough to it. People with one of their cones entirely missing/defective, can no longer distinguish that range, which means any colour that depends on being able to tell the difference between two overlapping ranges is now impossible. With a partial defect you can still tell these colours apart, but it's much more difficult. The reason Red/Green blindness is so common is because the molecules that produce those two cone types are very similar, so it takes only a minor change to effectively 'remove' one or the other. Plus, the name is actually ambiguous; given how the basic tests work, both having your 'green' cone and your 'red' cone missing lead to red/green colour blindness; They don't have the same exact effect, but it's still broadly a problem identifying red/green. Only having a defective/missing 'blue' cone causes a notably different result.
Man when you look into biochemistry you realise that life really shouldn't work at all. It's like building a supercomputer out of floppy bits of spaghetti floating around in a swimming pool.
Great video! Just to let you know, the conversion of the 11-cis-Retinal to 11-trans-Retinal actually involves what is known as a photo-catalyzed isomerization of one of the double bonds. This conversion of the molecule from the cis to the trans form is basically caused by the excitation of a set of molecular orbitals with visible light. This excitation rearranges the configuration of that bond so that it can act as a switch. You were mentioning the effects of slight conformational changes within the single bonds of the molecule as causing the change in the shape of the molecule. While this still does occur because of the relatively free nature of single bonds, this is not the reason for the conversion of the molecule from one form to another (in that case any long hydrocarbon would do the same job as 11-cis-Retinal, which we know is not the case!). In order to demonstrate that, you would actually have to remove one side of the molecule to show how the light actually causes a 'permanent', albeit temporary, chemical change from the cis to the trans form. I just thought this might be a useful detail to mention!
I noticed the single bonds were used to represent double bonds (just to clear up any confusion). It's just interesting to note that the cis and trans Retinal actually adopt fairly rigid conformations when not being catalyzed by light (this is what leads to its great ability to act like a 'switch'.
Thank you for explaining this Steve!! It's seems soooo fragile, the way so many things are so dependent on one another and how each little thing seems so subtle. Considering all the processes that has to take place, the little molecules that need to move about in the fluid to the time it takes for the sodium charge to build up, I'm impressed at how quickly we can perceive movements and changes in our vision.
Love the videos Steve. Great explanations of how we see colour. Could we have a video on why we don't see colour at low light levels even though the same mechanism is being used? Many thanks for all the effort you put in.
Great video .. One of your statement makes me confused - "Evolution works bit by bit" My question - Does Evolution has a target in mind (intelligence / intention) for which it works bit by bit choosing each molecule like an advanced bio-chemist ?
How complex would something have to be in order for us to acknowledge that it was purposed by a mind superior to ours? This is a real question. I wonder what it would take for someone who doesn't see design to say, "okay, someone/something made this." If a person found a wristwatch on an island, they would naturally assume it had been left there by someone; yet processes like vision, photosynthesis, reproduction and countless others are working harmoniously throughout earth's ecosystems, each one individually making our greatest techs look like tinker-toys by comparison. Can you think of anything that would be brilliant enough for you to consider that searching for it's creator would be scientific?
You playing around with the molecule gave me a new intuitive understanding of how molecules work I never grasped before. Like how they reach stable shapes due to how the forces attract and repel each other and then how outside energy can force them to switch into a new shape. Thanks!
I loved these 2 videos. I still have a few questions. Where exactly is the 'signal' and what is the mechanism generating the signal. Would it be possible to tap into the optic nerve fibers and read the signal electronically? How about generating the same signal for someone who is blind but still might have an optic nerve? Could you induce vision or even color?
I think you still look at things in a very linear manner. Sure, there is this nice cascade of switches from change of one molecule to the neuron firing... however there is so much going on in the meantime... these things does not happen isolated and that what makes biochemistry hard, there is this nice theoretical pathway of actions, but that is not how it really is, the cell needs to reactivate deactivated molecules, recycle the loose elements, destroy damaged proteins, synthesize new ones... and sometimes there is interference from a completely different pathway...
Hey Steve. I've been thinking about the perceiving of colors by human eye. Consider an animal who is able to see in IR or UV or Xray(!). Then it must see something more than RGB (or not?), and it is very hard for me to even imagine it. I would love to hear anything about the sensation of feeling and perceiving that new color. Thank you.
re - 6:45 Neuronal action potentials are freakin' AMAZING!!! I love the way a signal is propagated without any loss of signal strength!! I mean, the way we use conductors to carry/ convey/ transmit a charge is always going to result in some loss, due to the resistance of the conductor. While you can work around these shortcomings by increasing the current, etc, natural selection found a much more elegant solution via action potentials. I say "elegant," because it's not especially simple, but it's not impossibly complex, either. It's not an especially efficient method of propagating a signal/ charge, but it IS wonderfully ingenious. It's the kind of solution that a thinking agent would never think of but the kind of thing that natural selection would naturally select.
Absolutely brilliant! I am a high school student and these videos are a great pass time as well as educational for me. They are extremely informative and beautifully made. Thank you so much, and keep uploading these kinds of videos. I hope many more students turn to UA-cam to access amazing educational content such as yours.
Kudos to you for making good use of your time while in school. It will help you get further ahead in life later on. Whereas watching booty shakers on tic thot will rot your brain.
5:23 - 7:37 So, if I'm understanding correctly, when you look at a light, retinal molecules change shape which puts a force and changes the opsin protein harboring them. This shape change causes the protein to lose its transducin and causes a cascading molecular chain reaction that transforms cGMP [Sodium channel] molecules in the cell membrane into GMP, which is closed. This closure means sodium is no longer flowing in the cell, concentration goes down, and action potential is no longer present. This turns on the bipolar [NOT gate] cell and causes a signal to be interpreted. If all my understanding is valid, then I got questions: 1. Why can we see negative afterimages? Is it because of the change in sodium levels? Or is it just a unrelated event? 2. How do the cycle reset? Does the retinal molecule turn back? Does the opsin molecule get its transducin back? Does the GMP ever become cGMP again? Or is all this a one time change that is replace and not reset?
Hey, here I am watching this "new thumbnail and title for an old video that you really like but didn't get seen much at the time" video again. I really liked back then, and I really like it now... And thinking about how chemistry goes step by step I remembered this so called "Krebs cycle", and maybe you could figure out a way to make it a lot more entertaining to see. Just saying
HOW TO YOU MAKE COLOR 500 NM it dose not stimulate the red cone but it does the blue and green so if you try to use blue and green light to make it you will stimulate the red cone since blue light stimulates the red cone little and you cant stimulate the red cone to "make" 500 nm which is blueish green so can you not "make" this color with a RBG screen
It's scary how many similarities the universe has with the way computers compute things, the not gate cells work in a very similar way as the logic gates do on cpus, and then how quantum mechanics explain things in "simulation theory" and etc, such as the superposition property and the way we manage memory in software (pointers and how they only store the address of data which then allows the software to put the data in memory using pointers whenever there's a need, instead of constantly keeping it in memory, similar to how quantum objects behave differently when observed) ... Makes you think... Bit by bit, if you stitch things together from different fields of studies, more and more discoveries lead to credibility to the simulation theory. I ain't a believer myself, but it just makes you think, maybe the idea is not so absurd after all...
Ok, so: The doorman stops working, things get turned on and there's potential for action. At some point something might be coming in your eyes. Got it, cheers Steve!
I’m amazed that this entire process is happening thousands of times per second in every single cone cell. It gives you an idea of how fast molecular interactions can be. Like your brain can visually detect something within about 100 milliseconds. That’s fast for all this plus the processing to happen!
So the long process of resetting the retinol in the cone and rod cells is the reason for the image you saw staying in front of your eye when it suddenly goes dark (like, turning off the light in a windowless room)?
Some women can see a lot more color nuances than the rest of us, due to having one more color receptor in their eyes. I said some, because it's not a common trait.
Pretty much all systems which allow for analog signals to be converted to digital signals and vice versa make for very interesting topics. Such systems are present both in machines and in organics. Please cover some more of them in the future! I too hope your channel gets to vsauce, veritasium levels of popularity soon, looks like its on the ways 'swell!
11:06 I think you are oversimplifying this. In order to show a color you want to stimulate the three kinds of cells in the proportion you showed, but using combination of a number of other colors (most often tree but doesn't need to be). Unfortunately though you cannot just do it using a distinct color for each cell ("according to the amounts from the graph") , because their response is non-trivial and overlapping, e.g. you cant stimulate the "red" cell without stimulating the "green" one. You labeled them red, blue and green, but they are not pure red, blue and green sensors. There doesn't seem to be a color on that spectrum that can be solely "assigned" to one kind of sensor cell only. You want to figure out which combination of these complex stimuli responses to your base colors will be equivalent to the color you want to show. This doesn't look like a trivial problem to me, given the response curves. Mathematically speaking this reminds me of finding an orthogonal base in the color stimuli space (your base colors) and performing a change into that base from the one based on cellular response. Apparently Red, Green and Blue are close to being that orthogonal base.
@misium Well that's why you have the color matching functions. They're not responses from the cones; they come from experimental results of combining distinct colors to produce a particular perception. That's enough to produce your orthogonal basis I'm pretty sure. You don't have to worry about the cross over in the cones because it's not based on the cone response, it's based on perception. You just figure out what cone response combination corresponds to that perception. I think that's good enough.
Changing the absorption spectrum of a pigment by deforming the molecule using external forces instead of just using a different pigment is just such a biology thing to do... -.-
11:14 I noticed that at 430 nm and 470 nm, red activation and blue activation are almost identical, with green only being slightly different. I used www.w3schools.com/colors/colors_rgb.asp to look at RGB values of 25, 0, 150 and 25, 10, 150, but the perceived wavelength of light was identical. Doesn't this conflict with the model shown?
The first time i ever saw you Steve was when you were explaining how magenta light doesn't exist and blowing my mind. It's come full circle. (what's with the rockabilly look? looks good)
This Halloween, I am going to dress up as a retina protein.
lol no you won't
@@jesse4202 it’s a joke
I thought the green was the scariest
It's like this fragment of "The Little Prince" when he draws an elephant in a snake and adults say it's a hat. You can put white sheet and when people say "Oh, you dressed as a ghost" you'll say: "Wrong, it's retina protein" :D
I bet nobody saw that coming
This is one of your better videos. You managed to cram a great deal of one semester of biochemistry and physiology into little over 10 minutes, and it's still informative and not complicated. Excellent work, Steve.
Big Chungus is so funny HAHAHAHAHA
A good argument against 'irreducible' complexity is that we should absolutely expect extremely intricate multi -step processes to be the norm with evolution by natural selection
Something I have only recently learned about myself, is that I probably am affected by "visual snow". I thought it was everyone's experience, to at all times see a continuous field of tiny red, green, and blue dots, until I said something to my wife about it, and she hadn't the slightest idea of what I was talking about. The little colorful dots are almost overwhelming in the dark; I don't really see "black" at night, just red, green, and blue. In the day, I see quite normally, though if I sort of stop focusing on what I'm looking at, I can tell that it's really just the RGB dots.
you are presenting theese rather complex themes very simple, so an electrical engineer like me, that does'nt know much about biology could understand how this here works
kkep the good work up! :D
Another great video. Cheers for the share
one of your best videos yet. It was amazing to lern how eyes realy work :O
Fantastic stuff! I always wondered about this.
However - the brain is not electrical - it is chemo-electrical .. or electro-chemical .. there's a cycle .. you can't just call it electrical - and a lot of mistakes are made if you think like that.
Fantastic - you clearly get what non-linearity means .. so I also assume you know whta l;ocal minima are?
If you do, then you will understand how the visual system is adaptive?
Now .. consider this - the switched layers of adaptive signal processing are not one-way - there is always a feedback from each level to the next and back - and it operates as exclusive-or-gates to sharpen signal .. based on experience!!! How wonderful!
That is what "pins and needles" is when you disrupt your receptor network by laying on it while you are asleep . the next layer keeps polling the previous for instruction about what to suppress .. "pins and needles" is no more than your polling layers getting no reply - and it happens at the frequency of the polling .. I learned this by studying my wife who had(has) MS and tracking her experiential evidence from a known spinal lesion ,, so go figure?
Adaptive switching is a seriously important insight .. it means we can train ourselves to see other spectrae .. like if there was a need for that .. your graph of human spectral response is bogus .. if you go look, you will find that graph wildly deviates from person to person .. the graph does not show an error-spread .. so it's probably narrow and wrong. Well , that's my prediction from the standpoint of networks, chaos and how non-linearity creates adaptive switching .. happy to be shot down in flames?
Your explanations are so amazing! In almost every single one of your videos, you express a concept that isn't explained all that often in a simple, humorous, and surprisingly informative fashion. There is no unnecessary simplification, it follows the science beautifully, and everything is put together just right. This channel is one of my favorites on all of UA-cam and I never hesitate to share your new videos after watching them. I hope you go right to the very top.
Well said, I second that!
Well, there's always simplification. For example, why does light cause the molecule to switch from cis to trans? It has to do with a radical mechanism of isomerization. Why does the molecule's shape and its interaction with proteins change the frequencies it absorbs? That has to do with the wavefunction of the electrons and delocalization/resonance. I think Steve is really good at choosing precisely the right things to leave out to tell a coherent story, and that makes him a very good educator. He'll rise to the same prominence as Veritasium or VSauce if UA-cam let him.
@@TomatoBreadOrgasm doesn't "no unnecessary simplification" and "leaves out just the right things".. mean the same thing?
@@kaitlyn__L I suppose it does. 🙃
@@TomatoBreadOrgasm This is the most civilized resolution of any youtube comment I've ever read ever. Nice work everyone.
i want colorful ghosts to hold me as sweetly as they held those molecules :(
Boo
Boo you
:(
In the shape of Patrick Swayze?
There's a simulation software avalable for the experience.... It's called Pacman.
Hey there Mr. Mould. Nice vid!
So, uh... I don't know how to break it to you so I'll just go ahead and say it...
I think your studio is haunted. yep like with ghosts and the like
Believing is seeing.
EXPLAIN???? Vot does this "haunted" word mean Hmmmmmmmmmmmmmmmm? Vot sciencery is this?
And by colorful ghosts at that. Reminds me of Pacman...
Arm choppers to boot!
There are some snakes that got heat vision. They got cells that work similar to a microbolometer pixel below their noses. It's just 6 pixels but the anatomy allows them to combine the signal greatly and locate something to eat in the darkness. It's likely responsive to 6-12micron wavelengths. Which almost fit into LWIR thermal cameras.
There is a great paper with low of images that show a modified therma imaging camera to represent what said snake and "see". It's a difficult evolutionary questions because our own skin can sense heat by a different method but we never developed a optical centrum for it. It's likely due to the properties of liquids found in our body.. water does not transmit infrared radiation in those wavelengths, but blocks it. Water has been a vital step into forming the eye - homogenously.
The snakes sensors operate more like a pinhole camera.
I am a thermal imaging enthusiast and for me that is one of the most interesting topics of biology.
Interesting indeed, thanks
that kinda reminds me of how they use antenna arrays and some crazy triangulation like inference to image a black hole. would that be a reasonable analogy?
@@andrewaronson3364 interferometry does work by combining wavelengths of a synthetic aperture. It can't be done in a body, so the analogy falls apart.
It's more like yours ears. Where a a few sensors can give a full 'picture' because of the specific geometry and location between just two.
Pits: eye's without lenses.
Oh I'd love to have a video about that!
Holy shit. I mean really, holy shit this is amazing. All this is going on right now in my eyes! Freaking NOT gates!?!
7:07 the computer nerd inside me immediately thinks: so they are "active low"? :D
Edit: I appreciate the "not gate"
I'm guessing (as I have no knowledge of biology) that your brain wouldn't mind active low signals, it's like that 'you'll never know if other people experience color the same way' thing, so I wonder if it'd actually work if we simply removed the not gates or if they have some more important functionality as well.
Had the same thought. N then had a small bout of horror when it expanded to a 7 step process. Active low, invert, bit of a byte swap to get your pixel map, endian swap for dsp, dsp, nor matrix with some other channels, endian swap for interpreter, slice stream to fill framebuffer. Its a heck of a kludge, but does seem to work pretty good.
(Just a fantasy imagery of whats goin on, ive no idea. But sounds about right) Makes my brain hurt.
Especially at the genetic level, gene interaction networks are often thought of as analogous to circuit diagrams
@@Huntracony Imagine removing the not gate right now, and seeing every color inverted.
Now consider conditional Boolean Math? Not not?
Not how much not to not??
Minsky was a good go-to-guy about the topology of Boolean functions - specially in the realm of network adaptation. Fun stuff! He smashed neural net ideology by proving that NN cannot do exclusive or .. that was a breakthrough, but things developed from that . you can get Exor with enough topological layers - and specially when there is channel suppression from a feedback .. (complex back-prop) Last time I saw Minsky .. he was hiding his modular cognitive model to talk about how shaking-hands killed more people than guns. We are entering a time where the science of context becomes important. We will ultimately learn the absolute limits of atomic molecular switching - the blind-spot of the atom. But .. quantum reality shows a way forward. A Way that we have barely set foot upon, and learned that human feet are not good for this path? Think on that brother? Your insight will be valuable.
Fun fact: besides the iterative nature of evolution leading to all the weird and wonderful steps in a chemical reaction chain, another reason for the multiple steps is the activation energy required for each one. If the goal was to switch from molecule 1 straight to molecule 5, there isn't always enough energy available to raise into the new stable configuration, without more costly processes like raising the body temperature.
Thanks for the video, you are master of describing complex topics in simple terms!
Isn't that also why the electron transport chains are so long?
Yes. you get "it" Kudos! Please consider the mechanics that supports "adaptive switching? And dare I name it? Local minima?
In many cases, the different elements in the signal transduction chain also have other uses as amplifiers or points where regulators can affect the signal. I don't know whether it's true for this specific one, but it's often the case in these kinds of signal transduction chains in a cell.
Evolution? So you think ‘blind’ dumb luck figured this all out?
@@i9114 I don't know about him, but I do think. Evolution makes sense even if we consider it a dumb luck. Think about it. Because dumb luck needs to be lucky, it took millions of years for our eyes to be like that, for millions of dumb mistakes to occur in our ancestors DNA that just so happen to make something just a little better. (But don't forget about the insane majority of mistakes that led to death and disease of individuals. Thats why we only see the lucky ones, the unlucky are dead). Also, because dumb luck is dumb, our eyes are flawfull. The biggest flaw: Our retina is inverted. The photoreceptors are at the back and not at the front of it. That makes so that the light has to pass trough a layer of tissue, scattering it, and making our vision an inaccurate depiction of the light that enters our eyes. This is also why we have a blind spot. The nerves that come out of these cells need to turn around and go through a hole (the blind spot) in the retina to get to the brain. There are a lot of other problems. You should search about the origins of the human eye and also about its flaws, it is really interesting and I think that it makes much, much sense. Evolution is pretty half-assed if you think about it, you just have to give it some time to take something out of it... like... "millions of years" time... but the result is great... I mean.... it works... sometimes
Thanks for the recommendation to revisit this video! I don't think I was subbed when it was released
Psychotherapist: Ghost Steve Mould isn't real, he can't hurt you with chemistry!
Ghost Steve Mould holding a scary molecule: 4:09
The most amazing part of all this is that everything explained here happens in a matter of milliseconds, and has probably repeated something like millions of times while I was watching this. Being pretty much flawless, at least not in ways I can perceive.
In moments like this that my awe for evolution is the greatest.
Thanks Steve, I love what you do.
the question is: can I connect it to my arduino?
@@D4no00 the future probably can be described by neuronal arduinos. Ask Elon musk.
I'm pretty sure none of these processes come even close to flawless, it's all in just how robust to these aberrations the entire systems we're made up of are
@@AsmageddonPrince yeah, I know there's guaranteed degeneration through time, it's a given since no process is perfect. However I think it's impressive for this system to last 10 minutes, or years with little to no perceiving of flaws.
Sometimes it's amazing to imagine how someone can live for years without even noticing that their body could be tearing apart from malfunction.
This extremely complex and not pre designed system is way more resilient than I can ever imagine.
@@metametodo Believe me, it is't evolution. Self assembling atoms can not account for the ability to see or to have vision.This is a deliberate act of design. Evolution can not make atoms, self assemble, into living systems.
8:38 voice dubbed over mistakenly saying the word "pixels".
Damn, you noticed!
@@SteveMould much to your credit, it's cuz I hung on every word you said. I can't audibly detect the dub, but my lip reading is compulsive.
@@h7opolo
not to be rude, but are you hearing impaired by chance? i am, so lip reading is kind of important to me. I missed the mistake you caught though, and I forgive Steve.
@@holdmybeer i naively wish for hearing impairment as I am overly sensitive [to sound].
How is it even possible to notice something like this "compulsively"? I admire this talent!
I'm not really an expert or anything, but I'm pretty sure it just works.
God demmit Todd
@@keonix506 or Jensen
🤣
I dunno, I've seen some pretty convincing illusions that suggest otherwise :P.
iVision
"Advertising and other nefarious things like that"
The sheet molecules had me on the floor lmao
Hey Steve Great Video! We learned all of this in Medical school and the crazy thing is that in the retina not only the detection of light but also the processing of this information happen. You have different Horizontal cells which become activated by the photoreceptor cells and inhibit surrounding photoreceptor cells to create contrast. That is for example why dark areas seem on the edge to white areas much darker than being surrounded by dark areas. Fun fact: Most of the Proteins you have mentioned are reused by the body in different locations. cGMP in the nose and tongue for senses. Transducin which belongs to the family of G-Proteins are used in the Sympathicus(fight and flight) to increase your heart rate, constrict your Arteries,...
6:34 the doorman loses an arm but gain weight around his belly. Interesting conservation of mass there
Francois Roewer-Despres Perfectly balanced, as all things should be
Felix the Sloth I understood that reference
Great video. Nice CGI effects with the white and orange sheets ;-)
Sheet-G-I effects?
I thought those were PacMan ghosts EATIN TEH DOTZ!
The high budget illustrations in this video are really top notch.
The retinal-ghosts did it for me.
Great video! And amazing of you to use 4k50p, very much appreciated.
EDIT: omg that door sequence
And this complicated biochemistry is the reason for why we perceive more than 20fps as movement.
I think that is more to do with the brain processing than the biochemistry of the eye
Ron Wesilen it's literally both
Well yes, but this biochemistry is the first step and the brain won't get anything faster than this step allows. It uses various processing tricks to fill the gaps somehow, but this can't be done forever. ;)
Hi Steve! Very nice video, as always.
Just a little precision concerning what you explained around 11:31, the colour matching functions x(λ), y(λ), z(λ) are representations of the chromatic response of the observer, they don't exactly correspond to an amount of blue, green and red light.
Thanks for all your work !
So is the red/green overlap also part of the reason red-green colourblindness is a thing?
Kind of. Kind of not.
Red/Green colour blindness isn't the only possible type; there are others. (Every combination you can think of in fact).
It's just that Red/Green is the most common - and yes, that's because of how close together they are.
Colour blindness is generally caused by a defect in one or more cones.
This either means one of the cone types is less sensitive to light than it should be, is missing entirely, or has a defective protein that doesn't do it's job properly.
All of these have the effect of rendering one part of the colour range non-functional, or near enough to it.
People with one of their cones entirely missing/defective, can no longer distinguish that range, which means any colour that depends on being able to tell the difference between two overlapping ranges is now impossible.
With a partial defect you can still tell these colours apart, but it's much more difficult.
The reason Red/Green blindness is so common is because the molecules that produce those two cone types are very similar, so it takes only a minor change to effectively 'remove' one or the other.
Plus, the name is actually ambiguous; given how the basic tests work, both having your 'green' cone and your 'red' cone missing lead to red/green colour blindness;
They don't have the same exact effect, but it's still broadly a problem identifying red/green.
Only having a defective/missing 'blue' cone causes a notably different result.
Steve Mould leather jacket ASMR video when? (Joking aside, super great video!)
Wow, a single molecule made an entire Avenger?
Heh
Man when you look into biochemistry you realise that life really shouldn't work at all. It's like building a supercomputer out of floppy bits of spaghetti floating around in a swimming pool.
I completely agree. That would take a most talented builder, indeed!
Great video! Just to let you know, the conversion of the 11-cis-Retinal to 11-trans-Retinal actually involves what is known as a photo-catalyzed isomerization of one of the double bonds. This conversion of the molecule from the cis to the trans form is basically caused by the excitation of a set of molecular orbitals with visible light. This excitation rearranges the configuration of that bond so that it can act as a switch. You were mentioning the effects of slight conformational changes within the single bonds of the molecule as causing the change in the shape of the molecule. While this still does occur because of the relatively free nature of single bonds, this is not the reason for the conversion of the molecule from one form to another (in that case any long hydrocarbon would do the same job as 11-cis-Retinal, which we know is not the case!). In order to demonstrate that, you would actually have to remove one side of the molecule to show how the light actually causes a 'permanent', albeit temporary, chemical change from the cis to the trans form. I just thought this might be a useful detail to mention!
I noticed the single bonds were used to represent double bonds (just to clear up any confusion). It's just interesting to note that the cis and trans Retinal actually adopt fairly rigid conformations when not being catalyzed by light (this is what leads to its great ability to act like a 'switch'.
Thank you for explaining this Steve!! It's seems soooo fragile, the way so many things are so dependent on one another and how each little thing seems so subtle. Considering all the processes that has to take place, the little molecules that need to move about in the fluid to the time it takes for the sodium charge to build up, I'm impressed at how quickly we can perceive movements and changes in our vision.
Speed only makes sense within the framework created by these processes
Mom : retinol ghost is not real, it can't haunt you
4:20 : 😣
5:40 "Spooky action at no distance" ;-) Einstein approves :-P
Love the videos Steve. Great explanations of how we see colour. Could we have a video on why we don't see colour at low light levels even though the same mechanism is being used? Many thanks for all the effort you put in.
Thank you Steve very cool, this is enlightening
The second smaller peak for the red/long spectrum is at double the frequency of the larger peak.
a harmonic?
@@majacovic5141 Precisely!
@@gsurfer04 😁
I'm not going to lie the quality and consistency of this guys brain food is unparralled
I award him 3.14 Michelin Stars
I love how you explain things..
Just when I was getting confused, a colorful ghost shows up 😂
Great video .. One of your statement makes me confused - "Evolution works bit by bit"
My question -
Does Evolution has a target in mind (intelligence / intention) for which it works bit by bit choosing each molecule like an advanced bio-chemist ?
How complex would something have to be in order for us to acknowledge that it was purposed by a mind superior to ours? This is a real question. I wonder what it would take for someone who doesn't see design to say, "okay, someone/something made this." If a person found a wristwatch on an island, they would naturally assume it had been left there by someone; yet processes like vision, photosynthesis, reproduction and countless others are working harmoniously throughout earth's ecosystems, each one individually making our greatest techs look like tinker-toys by comparison. Can you think of anything that would be brilliant enough for you to consider that searching for it's creator would be scientific?
You playing around with the molecule gave me a new intuitive understanding of how molecules work I never grasped before. Like how they reach stable shapes due to how the forces attract and repel each other and then how outside energy can force them to switch into a new shape. Thanks!
I loved these 2 videos. I still have a few questions. Where exactly is the 'signal' and what is the mechanism generating the signal. Would it be possible to tap into the optic nerve fibers and read the signal electronically? How about generating the same signal for someone who is blind but still might have an optic nerve? Could you induce vision or even color?
Must have missed this one. Cheers for the relink
I think you still look at things in a very linear manner. Sure, there is this nice cascade of switches from change of one molecule to the neuron firing... however there is so much going on in the meantime... these things does not happen isolated and that what makes biochemistry hard, there is this nice theoretical pathway of actions, but that is not how it really is, the cell needs to reactivate deactivated molecules, recycle the loose elements, destroy damaged proteins, synthesize new ones... and sometimes there is interference from a completely different pathway...
Well that's my Halloween costume sorted then.
Very nice description!
"I'm always fascinated by how complicated biochemistry is" Yes, most things are more complex than originally perceived...
This blew my mind, you made such an awesome and complicated phenomenon so accessible and captivating. Thanks for the awesome video!
Looking a bit younger for some reason I'm from the future don't tell anyone
This is amazing, a brilliant way to explain something really complicated in an easy to consume and funny way 👍
That was one of my most searched videos since like 3 years... Thank you so much! you helped me a lot
How does tetrachromatics work then ? (Being one myself) Just curious :)
Love the Greaser look. Great content too!
Hey Steve. I've been thinking about the perceiving of colors by human eye. Consider an animal who is able to see in IR or UV or Xray(!). Then it must see something more than RGB (or not?), and it is very hard for me to even imagine it. I would love to hear anything about the sensation of feeling and perceiving that new color. Thank you.
holy shit im early, awesome video!
re - 6:45
Neuronal action potentials are freakin' AMAZING!!!
I love the way a signal is propagated without any loss of signal strength!! I mean, the way we use conductors to carry/ convey/ transmit a charge is always going to result in some loss, due to the resistance of the conductor. While you can work around these shortcomings by increasing the current, etc, natural selection found a much more elegant solution via action potentials. I say "elegant," because it's not especially simple, but it's not impossibly complex, either. It's not an especially efficient method of propagating a signal/ charge, but it IS wonderfully ingenious. It's the kind of solution that a thinking agent would never think of but the kind of thing that natural selection would naturally select.
Absolutely brilliant! I am a high school student and these videos are a great pass time as well as educational for me. They are extremely informative and beautifully made. Thank you so much, and keep uploading these kinds of videos. I hope many more students turn to UA-cam to access amazing educational content such as yours.
Kudos to you for making good use of your time while in school. It will help you get further ahead in life later on. Whereas watching booty shakers on tic thot will rot your brain.
As is life itself - just chemical reactions.
You're going as a ghost this Halloween, aren't you.
6:06 I misheard "molecule called Xi JinPing"
I know how my mum feels when I talk about science now.
BYU as in Brigham Young University?
Brilliant, but then I'm a sometime pharmacologist, I suspect to the average punter.... you may as well have been speaking dolphin .
No, pretty accessible for anyone with high school science, I think.
5:23 - 7:37 So, if I'm understanding correctly, when you look at a light, retinal molecules change shape which puts a force and changes the opsin protein harboring them. This shape change causes the protein to lose its transducin and causes a cascading molecular chain reaction that transforms cGMP [Sodium channel] molecules in the cell membrane into GMP, which is closed. This closure means sodium is no longer flowing in the cell, concentration goes down, and action potential is no longer present. This turns on the bipolar [NOT gate] cell and causes a signal to be interpreted.
If all my understanding is valid, then I got questions:
1. Why can we see negative afterimages? Is it because of the change in sodium levels? Or is it just a unrelated event?
2. How do the cycle reset? Does the retinal molecule turn back? Does the opsin molecule get its transducin back? Does the GMP ever become cGMP again? Or is all this a one time change that is replace and not reset?
Hey, here I am watching this "new thumbnail and title for an old video that you really like but didn't get seen much at the time" video again. I really liked back then, and I really like it now... And thinking about how chemistry goes step by step I remembered this so called "Krebs cycle", and maybe you could figure out a way to make it a lot more entertaining to see. Just saying
HOW TO YOU MAKE COLOR 500 NM
it dose not stimulate the red cone but it does the blue and green so if you try to use blue and green light to make it you will stimulate the red cone since blue light stimulates the red cone little and you cant stimulate the red cone to "make" 500 nm which is blueish green so can you not "make" this color with a RBG screen
It's scary how many similarities the universe has with the way computers compute things, the not gate cells work in a very similar way as the logic gates do on cpus, and then how quantum mechanics explain things in "simulation theory" and etc, such as the superposition property and the way we manage memory in software (pointers and how they only store the address of data which then allows the software to put the data in memory using pointers whenever there's a need, instead of constantly keeping it in memory, similar to how quantum objects behave differently when observed) ... Makes you think... Bit by bit, if you stitch things together from different fields of studies, more and more discoveries lead to credibility to the simulation theory. I ain't a believer myself, but it just makes you think, maybe the idea is not so absurd after all...
Wait they're actually described as "trans" and "cis" retinal? Neat, interesting to see that that terminology exists elsewhere.
Ok, so: The doorman stops working, things get turned on and there's potential for action. At some point something might be coming in your eyes. Got it, cheers Steve!
I’m amazed that this entire process is happening thousands of times per second in every single cone cell. It gives you an idea of how fast molecular interactions can be. Like your brain can visually detect something within about 100 milliseconds. That’s fast for all this plus the processing to happen!
hmm yes I would like to watch this video in public with subtitles
the subtitles: não
So the long process of resetting the retinol in the cone and rod cells is the reason for the image you saw staying in front of your eye when it suddenly goes dark (like, turning off the light in a windowless room)?
Actually surprisingly uncomplicated? You have a fantastic talent at explaining things in a fascinating and intuitive manner.
Some women can see a lot more color nuances than the rest of us, due to having one more color receptor in their eyes. I said some, because it's not a common trait.
Helpful information
so you dont need red Green and blue they are gust the most efficient you can use other colors they just have
simulate the cons the right way
really just a chemical reaction? i thought my boy is made out of magic and stuff
4:09 God damnit Steve put a warning next time. You scared the shit out of me!
Pretty much all systems which allow for analog signals to be converted to digital signals and vice versa make for very interesting topics. Such systems are present both in machines and in organics. Please cover some more of them in the future! I too hope your channel gets to vsauce, veritasium levels of popularity soon, looks like its on the ways 'swell!
i couldn't finish this video because of the scary ghost that kept showing up...
Quite the genius aye? Go ahead, explain consciousness then please....
7:30 does this mean blind people only see white or is that not what's affected by blindness?
Amazing bed sheet animation skillz! =D
that's how he picks up on sexy people at the club.
Sometimes your videos go beyond my capacity for absorption capacity/comprehension, but I stay til the end because you are such an excellent presenter!
Grease? lol. The hair, white shirt, and leather jacket... Grease
Steve, for what it's worth, you make a decent greaser
And you just confirmed that I'm actually physiologically nocturnal. Dang.
11:06 I think you are oversimplifying this. In order to show a color you want to stimulate the three kinds of cells in the proportion you showed, but using combination of a number of other colors (most often tree but doesn't need to be). Unfortunately though you cannot just do it using a distinct color for each cell ("according to the amounts from the graph") , because their response is non-trivial and overlapping, e.g. you cant stimulate the "red" cell without stimulating the "green" one. You labeled them red, blue and green, but they are not pure red, blue and green sensors. There doesn't seem to be a color on that spectrum that can be solely "assigned" to one kind of sensor cell only.
You want to figure out which combination of these complex stimuli responses to your base colors will be equivalent to the color you want to show. This doesn't look like a trivial problem to me, given the response curves.
Mathematically speaking this reminds me of finding an orthogonal base in the color stimuli space (your base colors) and performing a change into that base from the one based on cellular response. Apparently Red, Green and Blue are close to being that orthogonal base.
@misium Well that's why you have the color matching functions. They're not responses from the cones; they come from experimental results of combining distinct colors to produce a particular perception. That's enough to produce your orthogonal basis I'm pretty sure. You don't have to worry about the cross over in the cones because it's not based on the cone response, it's based on perception. You just figure out what cone response combination corresponds to that perception. I think that's good enough.
Changing the absorption spectrum of a pigment by deforming the molecule using external forces instead of just using a different pigment is just such a biology thing to do... -.-
So true
Not just tiny baby steps, but random ones... leading to such strange complexity.
Hey new sub here! Sent from SmarterEveryDay!
The horrors of the Na+ sneaking through the door at 6:23! :D
You make me feel I have been robbed by medical school. Seriously, this world needs a lot more conceptual teachers like you than it currently has!!!
11:14 I noticed that at 430 nm and 470 nm, red activation and blue activation are almost identical, with green only being slightly different. I used www.w3schools.com/colors/colors_rgb.asp to look at RGB values of 25, 0, 150 and 25, 10, 150, but the perceived wavelength of light was identical. Doesn't this conflict with the model shown?
The first time i ever saw you Steve was when you were explaining how magenta light doesn't exist and blowing my mind. It's come full circle.
(what's with the rockabilly look? looks good)
That was bloody fascinating... thank you, a great explanation of something we don't really think about often. That was great!
So elegantly simple, yet so amazingly complicated.
Love your videos.