Science
The shape that changed our world forever
Did you know that stop signs used to be yellow back in the 1920s even though red had already become known for stop in traffic lights the convention in science wasn't yet established and there were two major problems with red one there wasn't yet a way to make red pigment that wouldn't fade and two red is way harder to see at night you see your eye has three types of cones that detect color red green and blue cones but at night there isn't enough light to activate these cones in your retina and so your eyes rely on rods which are much better at perceiving low light and if we look at the wavelength sensitivity of rods you'll notice they actually don't even pick up red wavelengths when we see red at night it can only be picked up by cones and as a result red is the hardest color to see in low light so while a traffic light shining right is one thing a lowly lit red sign is completely different on top of this even in daylight our eyes are actually most sensitive to a yellow greenish color this is because it's right in the overlap between our red and green cone sensitivity peaking at about 550 nanometers making it a perfect option for visibility but not exactly one for consistency with red meaning stop so when did the switch to red signs happen and how did we overcome this hurdle it's actually one of the most ingenious and coolest inventions to ever come about retro reflection .
By TBH Agencia Exclusiva Colsanitasabout a year ago in Chapters
Strokes
Rapid onset of cerebral deficit or apoplexy. There are two types of strokes Non Hemorrhagic Stroke Hemorrhagic Stroke Non Hemorrhagic Stroke include Ischemic Stroke(thrombotic embolic)which means "Plaque formation in arterial wall, Plaque breaks away and gets lodge into brain"
By umamanidrahabout a year ago in Chapters
Only 12% of People Can See This!
stare at this image for five seconds and without realizing it the photoreceptors at the back of your eyes will start to become fatigued so much so that when this image turns white you see the green birds as red and the red background is green all of this happens because of biological processes in your eyes that link you to the lives of pollinating insects can help you design bedrooms or rooms in your house to be more satisfying and can also explain why women can see better than men seeing color is so freaking cool it kind of mixes science with sensation and over millions of years our eyes have evolved to see wavelengths on the electromagnetic spectrum roughly between 380 nanometers to around 700 nanometers that's it wavelengths longer than this you get into radio waves and microwaves which our eyes cannot see but they can send a text wavelength shorter than this you get into uv rays and gamma rays again your eyes cannot see but they can damage your cells and cause cancer but if we hone in on the wavelengths of color there are specific patterns that our eyes pick up most people see less than 450 nanometers as violet 450 to 485 nanometers as blue 500 to 550 nanometers as green 570 to 590 nanometers as yellow 590 to 625 nanometers you got gold 625 nanometers and above you get red now no object actually possesses any color which is so weird to say all an object does is absorb certain wavelengths of light and then reflect others for example this gorgeous teal seafoam coral blue is absorbing all the colors except for that seafoam teal gorgeous blue which is being reflected to your eye and your brain is interpreting this as color for example if you're looking at one of my favorite flowers the goldenrod which blooms in august the flowers are absorbing every wavelength of light except for the ones between 590 to 625 nanometers again as we said earlier which most people see as gold this light is sent to your cornea which bends it towards the pupil that controls the amount of light hitting the lens which focuses the wavelengths onto the back of your eye called the retina at the back of your eye the retina is covered in photoreceptor cells called cones you have around six million cone cells which absorb light and pass it onto the brain's visual cortex to be interpreted as color this is a biological process that's happening all the time you're looking at this screen i'm looking at this blue sky you're looking at me i'm looking at you and oh this is a connection my friends now your cone cells at the back of your eye are divided into three different types you got red cone cells green cone cells and blue cone cells rgb since you have three types you are visually trichromatic so you can walk around order your coffee and say by the way you me we're trichromatic some other animals for example are tetrachromatic and can even see within the uv wavelengths some birds some fish which i'm sorry are cooler than us that's a rad thing to do they are superheroes we are measly trichromats sit down folks because this science is complicated but the red cone optimal for perceiving the color red the blue cone optimal for perceiving the color blue and you guessed it the green cone optimal for perceiving the color grain but these cells work in combination for you to see over 10 million different colors unless you're 12 percent of women who can see way more than that more on that later but the nature of these cone cells are what create complementary colors that we perceive as satisfying now a complement is something that lacks a hole so for example this circle is a complement of this rectangle with the missing section together they make a hole that's a whole wh w-h-o-l-e not a hole like here here here or a couple down here if i showed you the ones down here we'd be on a different tube site according to the physics of light a complementary color for your eye are two colors that when combined produce white light it's a law of nature it's fascinating it's why we have complementary colors for our eyes and it has to do with how our cones work look at this black and white image if we put on the complementary colors of the original picture and you stare at this dot for a few seconds due to the specific stimulus on your eye the background we used and the perception of your red green and blue cone receptors when we put back this black and white image you see the color i do this all the time just for fun i'm like gosh dang my eyes and brain are insane the reason that this happens is because your eyes are so sensitive to these wavelengths that the cones become overused and oversaturated when looking at the same color the stimulus can start to spread to other cones nearby and when the stimulus is taken away the tired cones and your visual cortex default to seeing the complementary colors this is why we love looking at complementary colors beside each other they have energetic reciprocity going back to this image when staring at the green your green and blue cone cells become fatigued but the red isn't really being used in these sections so when you switch to white your brain reads these sections as red the red cone start to trigger your brain to see red it's all just about perception it's wild because it's like through these two little things that i'm seeing everything and living my life purple and gold are a reciprocal pair that our trichromatic eyes and the eyes of bees see very similarly golden rod and purple asters grow together so that bees find them attractive and this increases their pollination these flowers evolve to grow together to help pollination with bees they weren't for us but because of the energetic reciprocity of our cones being similar to that of bees we get to reap the benefits of this energetic beauty when looking at flowers when you see gold and you see purple and it feels good thank the bees when designing a room take a look at this light complementary color wheel if you focus on the complements of each other throughout your room you're going to be designing pleasing scenarios for the cones of your eye this can really help you make decisions about how you're going to design your room just think about the physiology of your freaking brain now for men seeing color can be more of an issue this is because the genes that encode red and green cones show high sequence homology on the x chromosome so although gender and sex can fall on a spectrum for the most part people who identify as women have xx chromosomes and people who identify as men have x y chromosomes and it's this y chromosome for people like me who have a y chromosome we are more likely to not be able to see red and green as well this is why statistically men are much more likely to be colorblind but on top of this there's a lot of new research but it is starting to be found out that 12 of women are actually tetrachromats they have an extra cone and can see a hundred times more color than the rest of us i got into a rabbit hole of all this research after being in nature and just looking at all these beautiful colors that were so soothing to my eye my brain my perception and it almost just was like what is beauty science has a hard time defining beauty you know beauty is in the eye of the beholder but when you look at these complementary light color wheels you start to realize there are some things we can do in our lives to better understand the physics of light our eyes and our brain and utilize this thinking to benefit our lives essentially this is just a video enticing you to get out there and of course stop and smell the flowers but also stop and look at those flowers see you next week for a new science video peace
By TBH Agencia Exclusiva Colsanitasabout a year ago in Chapters
Why You Shouldn’t Fear Death
One thing I can say about you right now, is that you are going to die, and yes this is scary, that is why today i am going to use scientific principles to help you understand and cope with the inevitable ending of your life. Grade 7 was the first i ever processed the concept of dying. I remember freezing in my tracks and thinking, wait so, this is all just going to end? Mommy! I eventually agreed with my own brain to suppres this fear and just go through the motions of life. I put excessive energy into schoolwork, got pimples, started date girls, realizing I only wanted to to them about the Lizzie McGuire movie, so I started dating guys, but it wasn't until my brilliant high school teachers made me fall head over heals in love with science, that a healthy perspective on death began to emerge. Your body is controlled by genes that code for proteins that lead to the formation of neural impulses that make constantly search out for meaning in life. This was first shown in a slightly violent study in the 1960. Participants visualized videos of victims suffering electrical shocks. the participants watching the videos would harshly judge the victims of the shocks as bad people. Psychologists and bioligists began to posit that humans feel an inate impulse to create meaning. In this case if you had to watch someone get electrically shocked, then they must have deserved it. It is now understood that according to your biology, you and everyone else on the planet will constantly be looking for meaning to life, and to death. So according to science at least you know you're not alone in any attempt to explain your own death. Now lets zoom out . Look at the night sky and you see the milky way galaxy full of an estimated 100 billion stars. That is is just one galaxy, there this a billion other galaxies in our observable universe, which is only expanded and getting bigger. How can we matter in such an expansive universe? Well, put both of your firsts together like this. That is roughly the size of your brain. An organ that has evolved over millions of years to have 86 billion neurons and even Glial cells to support it. There are more cells in your brain than stars in the milky way galaxy. You have an incredibly biological machine tucked wonderfully into your skull right now, that is astonishingly capable of conceptualizing the very idea that our universe is huge, expanding and vast. Science essential proves you are exceptionally smart. Before you die, you have unique opportunity to live a complex and wonderful life. Like all other forms of life on earth, you are made of atoms and atoms and molecules smashing into one another, absorbing energy from your environment, but unique to you, in your amazing brain, is the ability to contemplate your actions, make decisions, and care. Now let's zoom in. As a science teacher I know you should all remember drawing the electron diagrams of the first 20 elements of the periodic table. This is part of most, worldwide, high school science curriculum's. If you don't remember doing that, then on behalf of all science teachers everywhere... clap clap Eyes on the board please? Thank you. Can we all pay more attention in class? These diagrams were meant to show you that everything in our known universe is made up of protons, electrons, and neutrons. Yes we can get even smaller into the realm of quarks, Bosons or neutrinos, in fact, the sun is constantly emitting neutrinos with 100 trillion of them passing through your body every second. But let's stay on topic, we're talking today about death. We'll save neutrinos for another day. These protons, neutrons and electrons are all governed by forces that help explain, well, everything. How you evolved how you move, and yes, most importantly, how your phone works (hello?) You can describe your whole life based on the positions , velocities, and orientations of all of these atoms in your body, and this is called kinetic theory. You can use the kinetic theory to explain how plants absorb energy from the sun through photosynthesis. We eats plants or animals that have eaten plants, in order to gain that energy. Our bodies use that energy to power the process of the special molecule a called ATP, which powers every part of your life. Muscle contraction, transporting molecules throughout the body, synthesizing DNA etc. And yes, ATP is synthesized in the mitochondria, making the mitochondria the powerhouse of the cell. Infact, to stay alive, you'll typically create and use your whole bodyweight inATP molecules in one day. But, this also means that according to the kinetic, theory, regardless of your religion or spirituality, dying means that life as we know it ends. As your body loses the capability of creating ATP, and you start to physically fall apart. And one study found that when given the option to essentially produce ATP forever and live for eternity, overwhelming people said no, they want to eventually die. The fact that death is looming is what makes life so special. And in a wonderful way, death is really the only thing that we all have in common. In many ways, death is the meaning of life. Also passionately learning about science offers the unique opportunity to grasp what science can't explain. And knowing what science doesn't know can bring clarity. Takes these 3 examples of Shawn Caroll's epic book, the big picture. 1 the universe is expanding, 2 humans and chimpanzees share a common anscestor, 3 we should live happier and longer lives. The first 2 statements are rooted in science. We use impericism, resoning and observation to explain them. The last statement is not rooted in science. Science doesn't involve doing experiments to decide if people should lead happier, longer lives. Science just observes the world and it doesn't say whether something is right or wrong. Another way of looking at this is through evolution. Evolution is an incredible process based on millions of years of change, adaptation, and impulses. It just follows the laws of nature, but can't explain how to live your life. You have the power to change your life. You have the power to care about others, and you have the power life love laugh, babe, and that is incredible. After you do inevitably die, you live on in the memories of others for the time being. And then, you'll be forgotten in the change and passing of life. There are this any atoms in your body which insanely amazing but, these little guys will eventually stop being you. And even though collectively they will no longer be you, it is comforting to know that they will remain on earth after you have left. Once gone, even if the whole human race vanishes, the universe will still be here doing its thing, moving along according to the laws of nature. But sticking to right now, according to science, we are all sharing this universe, sharing the same laws of nature and sharing the same task of creating meaning to what is happening around us. It is estimated that you have around 3 billion heat beats in a life time, so it is up to you to make them count. So, some scientific reasons to not fear death is 1, we humans are meaning making machines, we can choose to not make death a dreadful thing, and choose to live a meaningful life. 2, you might feel insignificant, but there lies within you more neural cells than stars in our universe. 3, eventually you will stop making ATP, but the fact that it ends, is what makes life so great. 4, science can't explain everything, so it us to you to choose to live your life to your fullest. And 5, eventually your atoms will atoms will stop being you, but you were made of will likely carry on for eternity. Science is a brilliant way to view the complexity of your life and help inform how you live it, while here, and thankfully, if you are still watching this, congratulations, you are alive, but again if there's one thing I can say about you right now, it is that you, yes you are going to die. I'm constantly on a quest to deal with my own fear of death and this book helped me with this video a lot, its called the picture by Shawn Carroll it is amazing, check it out. It talks about morality, consciousness, life, death, and all through the realm of science. We'll leave the link to get the book below and make sure you subscribe for more science videos, peace.
By TBH Agencia Exclusiva Colsanitasabout a year ago in Chapters
What's Inside A Wasp's Nest | What's Inside?
This is a wasp next. In the wild, some of these nests are built underground using clay or mud. But you might be most familiar with the paper nests -- the ones built out of saliva and pulp, typically found attached to buildings or trees.
By TBH Agencia Exclusiva Colsanitas2 years ago in Chapters
