Originally posted by Unnamed Headcrab 9001:

Hey, Vsauce. Michael here. Let's take a moment to recognize the heroes who count. Canadian Mike Smith holds the world record for the largest number counted to in one breath - 125. But the world record for the largest number ever counted to belongs to Jeremy Harper from Birmingham, Alabama. In order to set the record, Harper never left his apartment. He got regular sleep, but from the moment he woke up in the morning until the moment he went to bed at night, Harper did nothing but count. He streamed the entire process over the Internet and raised money for charity while doing it, but after three months of counting all day, every day, he finally reached the world record - 1 million. Now, a million might not sound like a lot, but think of this way. One thousand seconds is about 17 minutes, but a million seconds is more than 11 days. And a billion seconds, well, that's more than 31 years. There's no full video online of Harper counting all the way to a million, but you can watch John Harchick count all the way to 100,000, if you have 74 hours to spare. John also has some other channels. One involves more than 300 videos of himself eating carrots. Another, more than 3,000 videos of himself drinking water. Many of John's videos literally have no views.

They are as lonely as a video on YouTube can get. A great way to find such videos is a website made by Jon van der Kruisen. This website auto-plays videos on YouTube that no one has yet watched. John and Jeremy, as well as Mike, the one breath counter counted like this. 1, 2, 3, 4, 5, 6, 7 and so on. But that's not the only way to count. And it doesn't seem to be the one we're born with.

Additive counting is the one we're all familiar with, where each next step is just one added to the last. But what if we multiply it by a number instead? Well, that kind of counting is logarithmic, from "arithmos" meaning number and "logos" meaning ratio, proportion. On this scale, similar distances are similar proportions. One is a third of three and three is a third of nine. Four is a third of 12 and so on. Our brains perceive the world around us on a logarithmic scale. It's believed that almost all of our senses are multiplicative, not additive.

For example, how loud we perceive a sound to be. Two boomboxes playing at the same volume don't sound twice as loud as one. In order to make a sound that is perceived as being about twice as loud as one boombox, you actually need ten times as many, so 10. And to double that loudness, you would need a hundred. And to double that loudness, you would need a thousand. Having an intuitive sense of logarithmic scales built into your brain is probably an advantage when it comes to natural selection and survival, because often proportion matters more than absolute value. For example, "is there one lion hiding over there in the shadows or two?" is a very different question than "are there ninety six lions about to attack us or ninety seven?" Sure, in both cases I'm just talking about one extra lion, but adding one lion to one lion, doubles the threat. Adding one lion to 96, well, that's basically nothing.

Logarithmic thinking and feeling may explain why life seems to speed-up as we get older. It seems like I was a child for ever. And in college, in my early 20's, just whizzed by. And logarithmically, that makes sense, because each new year that I live is the smaller fraction of all the other years I've already lived. When you turn 2 years old, the last year of your life is half your life. But when you turn 81, that last year that you've lived, well, that's just a tiny part of the other 80 that you know. Logarithmic thinking isn't always helpful, especially in scenarios where proportion doesn't logically matter but we, nonetheless, act like it does. One of my favorite examples is the psychophysics of price paradox. This is something almost all of us do.

Researchers found consistently that people are willing to put a lot of effort into saving 5 dollars of a 10 dollar purchase, but they won't put much effort into saving 5 five dollars of a 2,000 dollar purchase. It's 5 dollars saved either way, but our natural obsession with proportion leads us astray. Take a look at these pictures. Can you tell how many objects are in each of them? You probably can. It's like really easy. You can tell if there are zero, one, two, three or four objects in a photo without even needing to count. How are you doing that? Is it some sort of sixth sense? No.

Psychologists call it "subitizing." We can, intuitively, at a glance, determine whether there are about four or fewer objects in a photo. This has been part of human culture for a very long time and it may be the reason so many tally systems from all over the world all through history wind up having to do something different when counting the number five. When estimating or comparing amounts above 4, the brain uses what's known as an approximate number system. It's a psychological ability we have. It's about 15 percent accurate. It two amounts are at least 15 percent different, we can tell. So, for example, 100 objects and 115 or a thousand and 1,150 or 1,200.

If you wanna test the accuracy of your approximate number system Panamath has a pretty good test. We often take linear additive counting for granted, but it's not granted to us. We aren't born with it. We are, however, born with the ability to subitize and use an approximate number system. Children younger than the age of three can tell, without counting, that this line of 4 coins contains fewer coins than this line of 6, even if you spread the 4 coins out into a line that is physically bigger, longer than this line of 6. However, mysteriously, around the age of 3.5, children lose this ability and begin saying that this line of 6 coins contains fewer coins than this long line of just 4 coins, possibly because around this age the physical world of objects, physical sizes, is more salient in their minds. But then, when they begin to learn linear counting, they reverse back and begin again correctly saying that this line of 6 contains more coins than this line of 4, around the age of 4.

The smallest physical thing science could ever hope to observe is the Planck length. In order to look at anything smaller, you'd need to have so much energy concentrated in such a small area a black hole would form and you would lose whatever you were looking at. Okay, with that in mind, here's a question. What number is halfway in-between 1 and 9. 5 seems like the obvious answer. There are four numbers on either side of 5, it's halfway between, right? Well, if you ask this question of a young child or a member of a culture that doesn't teach a linear additive number line, their answer will be 3. You see, they are exhibiting the human mind's natural logarithmic tendency, because 3 in that sense makes sense. Three is three times larger than 1, and 9 is three times larger than 3. Three is in the middle, proportionately.

But what if we took that logarithmic number line and change the one to be the smallest thing we can observe, the Planck length, and the nine to be the largest thing we can observe, the observable universe. What would go in the middle? Well, as it turns out, we would. The number of Planck lengths you could stretch across a brain cell is equal to the number of your brain cells it would take to stretch all the way across the observable universe. sold So, welcome to the middle. And as always, thanks for watching. Hello again. The YouTube channel Field Day recently gave me an opportunity to explore Whittier, Alaska, one of the strangest places humans call home. To see why and to see me investigate, talk to the locals, click the link in this video's description or on the annotation here on this video. It was really fun, so give it a little lookie look.

Originally posted by Unnamed Headcrab 9001:

Hey, Vsauce. Michael here. Where are your fingers? Seriously. It's a pretty easy question. You should be able to answer it. But how do you know? How does anyone know anything?

You might say, well, I know where my fingers are. I'm looking right at them. Or, I can touch them, I can feel them, they're right here and that's good. Your senses are a great way to learn things. In fact, we have way more than the usual five senses we talk about. For instance, your kinesthetic sense, proprioception. This is what the police evaluate during a field sobriety test. It allows you to tell where your fingers and arms and head and legs in your body is all in relation to each other without having to look or touch other things. We have way more than five senses, we have at least twice as many and then some. But they're not perfect.

There are optical illusions, audio illusions, temperature sensation illusions, even tactile illusions. Can you turn your tongue upside down? If so, perfect. Try this. Run your finger along the outer edge of the tip of your upside down tongue. Your tongue will be able to feel your finger, but in the wrong place. Our brains never needed to develop an understanding of upside down tongue touch. So, when you touch the right side of your tongue when it's flipped over to your left side you perceive a sensation on the opposite side, where your tongue usually is but isn't when it's upside down. It's pretty freaky and cool and a little humbling, because it shows the limits of the accuracy of our senses, the only tools we have to get what's out there in here.

The philosophy of knowledge, the study of knowing, is called epistemology. Plato famously said that the things we know are things that are true, that we believe and that we have justification for believing. those justifications might be irrational or they might be rational, they might be based on proof, but don't get too confident because proven is not a synonym for true. Luckily, there are things that we can know without needing proof, without needing to even leave the house, things that we can know as true by reason alone. These are things that we know a priori. An example would be the statement "all bachelors are unmarried." I don't have to go survey every bachelor on earth to know that that is true. All bachelors are unmarried because that's how we define the word bachelor. Of course, you have to know what the words bachelor and unmarried mean in the first place. Oh, you do? Okay. Perfect. That's great. But how do you know?

This time I mean functionally, how do you know? Where is knowledge biologically in the brain? What are memories made out of? We are a long way from being able to answer that question completely but research has shown that memories don't exist in the brain in single locations. Instead, what we call a memory is likely made up of many different complex relationships all over the brain between lots of brain cells, neurons. A major cellular mechanism thought to underlie the formation of memories is long-term potentiation or LTP. When one neuron stimulates another neuron repeatedly that signal can be enhanced overtime LTP, wiring them more strongly together and that connection can last a long time, even an entire lifetime. A collection of different brain cells, neurons that fire together in a particular order over and over again frequently and repeatedly can achieve long-term potentiation, becoming more sensitive to each other and more ready to fire in the exact same way later on in the future. They're a physical thing in your brain, firing together more easily because you strengthen that pattern of firing. You memorized. This branching forest of firing friends looks messy, but look closer. It could be the memory of your first kiss. A living souvenir of the event. If I were to go into your brain and cut out those cells, could I make you forget your first kiss or could I make you forget where your fingers are? Only if I cut out a lot of your brain. Because memories aren't just stored in one relationship, they're stored all over the brain. The events leading up to your first kiss are stored in one network, the way it felt to the way it smelled in different networks, all added up together making what you call the memory of your first kiss.

How many memories can you fit inside your head? What is the storage capacity of the human brain? The best we can do is a rough estimate, but given the number of neurons in the brain involved with memory and the number of different connections a single neuron can make Paul Reber at Northwestern University estimated that we can store the digital equivalent of about 2.5 petabytes of information. That's the equivalent of recording a TV channel continuously for 300 years. That's a lot of information. That is a lot of information about skills you can do and facts and people you've met, things in the real world. The world is real, right? How do you know?

It's a difficult question, but it's not rocket science. Instead, it is asking whether or not rocket scientists even exist in the first place. The theory that the Sun moved around the earth worked great. It predicted that the Sun would rise every morning and it did. It wasn't until later that we realized what we thought was true might not be. So, do we or will we ever know true reality or are we stuck in a world where the best we can do is be approximately true? Discovering more and more useful theories every day but never actually reaching true objective actual reality. Can science or reason ever prove convincingly that your friends and YouTube videos and your fingers actually exist beyond your mind? That you don't just live in the matrix?

No. Your mind is all that you have, even if you use instruments, like a telescope or particle accelerators. The final stop for all of that information is ultimately you. You are alone in your own brain, which technically makes it impossible to prove that anything else exists. It's called the egocentric predicament. Everything you know about the world out there depends on and is created inside your brain. This mattered so much to Charles Sanders Peirce that he drew a line between reality, the way the universe truly is, and what he called the phaneron, the world as filtered through our senses and bodies, the only information we can get. If you want to speak with certainty you live in, that is you react to and remember and experience your phaneron, not reality. The belief that only you exist and everything else, food, the universe, your friends are all figments of your mind is called solipsism. There is no way to convince a solipsist that the outside world is real. And there is no way to convince someone who doubts that the universe wasn't created just three seconds ago along with all of our memories. It's a frightening realization that we don't always know how to deal with. There's even The Matrix defense.

In 2002 Tonda Lynn Ansley shot and killed her landlady. She argued that she believed she was in the matrix, that her crimes weren't real. By using the matrix defense, she was found not guilty by reason of insanity, because the opposite view is just way healthier and common. It's called realism. Realism is the belief that the outside world exists independently of your own phaneron. Rocks and stars and Thora Birch would continue to exist even if you weren't around to experience them. But you cannot know realism is true. All you can do is believe.

Martin Gardner, a great source for math magic tricks, explained that he is not a solipsist because realism is just way more convenient and healthy and it works. As to whether it bothered him that he could never know realism was true, he wrote, "If you ask me to tell you anything about the nature of what lies beyond the phaneron, my answer is how should I know? I'm not dismayed by ultimate mysteries, I can no more grasp what is behind such questions as my cat can understand what is behind the clatter I make while I type this paragraph." Humble stuff. What strikes me is the cat.

Cats do not understand keyboards, but they know the keyboards are a fun place to be. It's a great way to get the attention of a human, they're warm and exciting, surrounded by noises and flashing lights plus cats love to get their scent on whatever they can, a mark of their existence. We aren't that much different, except instead of keyboards we have the mysteries of the universe. We will never be able to understand all of them.

We won't be able to ever answer every single question, but walking around in those questions, exploring them, is fun. It feels good. And as always, thanks for watching. Do you want more unanswered questions? Well, you're in luck. Today, nine other amazing channels on YouTube have made videos about questions we still haven't fully answered. Alltime10s has organized them and to watch them all click the annotation at the end of this video or the link at the top of the description. Enjoy.

Originally posted by Unnamed Headcrab 9001:

Hey, Vsauce. Michael here. Where are your fingers? Seriously. It's a pretty easy question. You should be able to answer it. But how do you know? How does anyone know anything?

You might say, well, I know where my fingers are. I'm looking right at them. Or, I can touch them, I can feel them, they're right here and that's good. Your senses are a great way to learn things. In fact, we have way more than the usual five senses we talk about. For instance, your kinesthetic sense, proprioception. This is what the police evaluate during a field sobriety test. It allows you to tell where your fingers and arms and head and legs in your body is all in relation to each other without having to look or touch other things. We have way more than five senses, we have at least twice as many and then some. But they're not perfect.

There are optical illusions, audio illusions, temperature sensation illusions, even tactile illusions. Can you turn your tongue upside down? If so, perfect. Try this. Run your finger along the outer edge of the tip of your upside down tongue. Your tongue will be able to feel your finger, but in the wrong place. Our brains never needed to develop an understanding of upside down tongue touch. So, when you touch the right side of your tongue when it's flipped over to your left side you perceive a sensation on the opposite side, where your tongue usually is but isn't when it's upside down. It's pretty freaky and cool and a little humbling, because it shows the limits of the accuracy of our senses, the only tools we have to get what's out there in here.

The philosophy of knowledge, the study of knowing, is called epistemology. Plato famously said that the things we know are things that are true, that we believe and that we have justification for believing. those justifications might be irrational or they might be rational, they might be based on proof, but don't get too confident because proven is not a synonym for true. Luckily, there are things that we can know without needing proof, without needing to even leave the house, things that we can know as true by reason alone. These are things that we know a priori. An example would be the statement "all bachelors are unmarried." I don't have to go survey every bachelor on earth to know that that is true. All bachelors are unmarried because that's how we define the word bachelor. Of course, you have to know what the words bachelor and unmarried mean in the first place. Oh, you do? Okay. Perfect. That's great. But how do you know?

This time I mean functionally, how do you know? Where is knowledge biologically in the brain? What are memories made out of? We are a long way from being able to answer that question completely but research has shown that memories don't exist in the brain in single locations. Instead, what we call a memory is likely made up of many different complex relationships all over the brain between lots of brain cells, neurons. A major cellular mechanism thought to underlie the formation of memories is long-term potentiation or LTP. When one neuron stimulates another neuron repeatedly that signal can be enhanced overtime LTP, wiring them more strongly together and that connection can last a long time, even an entire lifetime. A collection of different brain cells, neurons that fire together in a particular order over and over again frequently and repeatedly can achieve long-term potentiation, becoming more sensitive to each other and more ready to fire in the exact same way later on in the future. They're a physical thing in your brain, firing together more easily because you strengthen that pattern of firing. You memorized. This branching forest of firing friends looks messy, but look closer. It could be the memory of your first kiss. A living souvenir of the event. If I were to go into your brain and cut out those cells, could I make you forget your first kiss or could I make you forget where your fingers are? Only if I cut out a lot of your brain. Because memories aren't just stored in one relationship, they're stored all over the brain. The events leading up to your first kiss are stored in one network, the way it felt to the way it smelled in different networks, all added up together making what you call the memory of your first kiss.

How many memories can you fit inside your head? What is the storage capacity of the human brain? The best we can do is a rough estimate, but given the number of neurons in the brain involved with memory and the number of different connections a single neuron can make Paul Reber at Northwestern University estimated that we can store the digital equivalent of about 2.5 petabytes of information. That's the equivalent of recording a TV channel continuously for 300 years. That's a lot of information. That is a lot of information about skills you can do and facts and people you've met, things in the real world. The world is real, right? How do you know?

It's a difficult question, but it's not rocket science. Instead, it is asking whether or not rocket scientists even exist in the first place. The theory that the Sun moved around the earth worked great. It predicted that the Sun would rise every morning and it did. It wasn't until later that we realized what we thought was true might not be. So, do we or will we ever know true reality or are we stuck in a world where the best we can do is be approximately true? Discovering more and more useful theories every day but never actually reaching true objective actual reality. Can science or reason ever prove convincingly that your friends and YouTube videos and your fingers actually exist beyond your mind? That you don't just live in the matrix?

No. Your mind is all that you have, even if you use instruments, like a telescope or particle accelerators. The final stop for all of that information is ultimately you. You are alone in your own brain, which technically makes it impossible to prove that anything else exists. It's called the egocentric predicament. Everything you know about the world out there depends on and is created inside your brain. This mattered so much to Charles Sanders Peirce that he drew a line between reality, the way the universe truly is, and what he called the phaneron, the world as filtered through our senses and bodies, the only information we can get. If you want to speak with certainty you live in, that is you react to and remember and experience your phaneron, not reality. The belief that only you exist and everything else, food, the universe, your friends are all figments of your mind is called solipsism. There is no way to convince a solipsist that the outside world is real. And there is no way to convince someone who doubts that the universe wasn't created just three seconds ago along with all of our memories. It's a frightening realization that we don't always know how to deal with. There's even The Matrix defense.

In 2002 Tonda Lynn Ansley shot and killed her landlady. She argued that she believed she was in the matrix, that her crimes weren't real. By using the matrix defense, she was found not guilty by reason of insanity, because the opposite view is just way healthier and common. It's called realism. Realism is the belief that the outside world exists independently of your own phaneron. Rocks and stars and Thora Birch would continue to exist even if you weren't around to experience them. But you cannot know realism is true. All you can do is believe.

Martin Gardner, a great source for math magic tricks, explained that he is not a solipsist because realism is just way more convenient and healthy and it works. As to whether it bothered him that he could never know realism was true, he wrote, "If you ask me to tell you anything about the nature of what lies beyond the phaneron, my answer is how should I know? I'm not dismayed by ultimate mysteries, I can no more grasp what is behind such questions as my cat can understand what is behind the clatter I make while I type this paragraph." Humble stuff. What strikes me is the cat.

Cats do not understand keyboards, but they know the keyboards are a fun place to be. It's a great way to get the attention of a human, they're warm and exciting, surrounded by noises and flashing lights plus cats love to get their scent on whatever they can, a mark of their existence. We aren't that much different, except instead of keyboards we have the mysteries of the universe. We will never be able to understand all of them.

We won't be able to ever answer every single question, but walking around in those questions, exploring them, is fun. It feels good. And as always, thanks for watching. Do you want more unanswered questions? Well, you're in luck. Today, nine other amazing channels on YouTube have made videos about questions we still haven't fully answered. Alltime10s has organized them and to watch them all click the annotation at the end of this video or the link at the top of the description. Enjoy.

Originally posted by Unnamed Headcrab 9001:

my dad sucked off Adolf Hitler and my dad is called Adolf Hitler

Originally posted by PetriDishBoy:

Originally posted by Sir. Paulord:

Hitler did nothing wrong

Originally posted by Sir. Paulord:

Originally posted by Unnamed Headcrab 9001:

I suck dick.

Hitler did nothing wrong

Originally posted by Unnamed Headcrab 9001:

I suck dick.