Vision Is Actually A Chemical Reaction

This Halloween, I am going to dress up as a retina protein.

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 YouTube and I never hesitate to share your new videos after watching them. I hope you go right to the very top.

i want colorful ghosts to hold me as sweetly as they held those molecules :(

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.

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.

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!

Psychotherapist: Ghost Steve Mould isn't real, he can't hurt you with chemistry! Ghost Steve Mould holding a scary molecule: 4:09

7:07 the computer nerd inside me immediately thinks: so they are "active low"? :D Edit: I appreciate the "not gate"

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

8:38 voice dubbed over mistakenly saying the word "pixels".

The high budget illustrations in this video are really top notch.

The sheet molecules had me on the floor lmao

Holy shit. I mean really, holy shit this is amazing. All this is going on right now in my eyes! Freaking NOT gates!?!

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,...

"Advertising and other nefarious things like that"

6:34 the doorman loses an arm but gain weight around his belly. Interesting conservation of mass there

The retinal-ghosts did it for me. Great video! And amazing of you to use 4k50p, very much appreciated. EDIT: omg that door sequence

I'm not really an expert or anything, but I'm pretty sure it just works.

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.