Hey, Vsauce. Michael here. What's normal? Are you normal? Well, today let's bathe our brains with those questions and scrub down with things that are surprising and counterintuitive. What does it mean to be normal in the first place?
Well, maybe it just means to be average. But an average can be a bit weird, a bit misleading. For instance, think of this way. The average human has one breast and one testicle. Also, the
average person has not climbed to the top of Gangkhar Puensum. In fact, no one has. Gangkhar Puensum is considered the tallest mountain on Earth that has yet to be summited. And it's unlikely it ever will be soon. It lies on the border of China and Bhutan
and local governments believe the area to be holy, and no mountaineering or climbing is allowed. But don't worry, there are plenty
more. There are at least a hundred other recognised peaks that are quite tall and remain unsummitted. That's great. It's surprising to think that Earth has
so many places that still have yet to be conquered or explored. At least, we were all
born here on Earth. Derek, from the YouTube channel Veritasium, where were you born? A small Australian town called Traralgon. But were you really born there? I'm suspicious of Derek's answer because saying that you were born on Earth's surface, is like saying you were born in a taxicab. The taxicab may still be around, but is
it in the exact same location that it was at the moment of your birth? Probably not.
Like a taxicab, the Earth is moving, and it's moving quickly. For one, the Earth is spinning. This is real time
footage of Earth spinning you don't notice much movement at all, but that's just because Earth is so large. To a distant observer beyond Earth, two seconds from now you will be an entire kilometre east
from where you are now. Earth is also orbiting around the Sun, quickly. Three days ago, I was in Singapore. From
the reference frame of Earth's surface, Singapore is 6,000 kilometres
away from this place. Sydney, Australia. But, in terms of Earth
orbiting around the Sun, three days ago I wasn't just 6,000 kilometres away, I was more than 7 million. The point is, where you were born, when you were born, is now just an empty region of space Earth will never, ever return to. My favourite surprise is
the solution to the Three Prisoners problem. It's related to the Monty Hall
problem but the stakes are higher. Its solution is notoriously
counter-intuitive. Let's say that myself, Kevin and Jake, have been arrested.
And we are told that tomorrow morning two of us will be executed. We don't know which two, so it's a terrible night. But if I ask a guard to tell me
something about what happens tomorrow and the guard says "Michael, I won't tell
you anything about your fate and I won't tell you who lives, but I will
tell you this little piece of information: tomorrow morning Jake is one of the guys who will be executed." What a relief(!) I used to have a one
in three chance of being the one who lives, but now that I know Jake dies, it's just
between Kevin and I. My chances of living have gone up from 1 in 3 to 1 in 2. This is great. Well, if I thought that I would actually be wrong. In fact, my chances of living
haven't changed at all and Kevin's are paradoxically now twice
as good as mine. How can that be? Well, take a look at this. This circle represents the three possibilities. Either tomorrow Jake will live, Kevin will live or I will live. The hearts represent life. Isn't that beautiful? Now, let's focus on what the guard can tell me. In the case that Jake is the one who has been
selected to live, both Kevin and myself will die tomorrow. But the guard cannot tell me anything
about myself, and he cannot tell me who lives, so if Jake is the one chosen to
survive all the guard can tell me is that Kevin will be one of the guys
who dies tomorrow, that's it. Now, in this case, where Kevin is the guy selected to live, both myself
and Jake will die tomorrow, but the guard can't tell me about myself and cannot tell me who lives. So all the
guard can say is that tomorrow Jake is one of the guys who will die.
Here's where it gets interesting. If I am the one who has been picked to
live tomorrow, the guard has a choice; he can either tell me that Kevin is the one who will die tomorrow or he
can tell me that Jake is one of the guys who will
die tomorrow. Well, look at what we've got here. If the guard tells me that Jake is one of the guys who will die tomorrow, I'm only faced now with these possibilities. In one-third of these cases I am the survivor, and in two-thirds of these cases Kevin is the survivor. My chances haven't changed and Kevin's are now twice as good as mine used to be. It is a beautiful day here in Sydney.
Before I arrived in Australia I was in Singapore, where it was also beautiful but incredibly humid. The air felt thick to move through and breathe, but in actuality humid air is less dense than dry air. Derek, tell us about Avogadro's Law. Well, Avogadro came up with the idea that in a given volume of gas at a given
temperature and pressure, there will be always the same number of gas particles.
Doesn't matter what the gas is, if it's helium or nitrogen or oxygen. And that holds truth for air, which is a mixture of gases. That's right. So, it's got nitrogen and oxygen principally. But if it's humid air, then you replace
some of those nitrogens and oxygens with water. And water is wider than the diatomic nitrogen and oxygen that
exists in our atmosphere. That's right.
Oxygen and nitrogen have masses of 32 and 28, whereas water is just 18. Humid air is actually much less dense than dry air. It's lighter and things can move
through it more easily. This is especially true when it comes to baseballs. A baseball travels through humid air more easily, and further, with the same amount of
energy. If air becomes more humid and decreases drag by only five
percent that can mean the difference between a fly ball and a home run. This became a problem when indoor baseball stadiums started to
play around with the idea of turning on the air conditioning when
the rival team came up to bat. Essentially, the air conditioning made the air dryer, therefore thicker and made the rival team hit baseballs shorter distances. The word normal, by the way, is homological.
What does that mean? A homological adjective describes itself. For instance, the word tiny is pretty tiny. It's a small word. The word unhyphenated is unhyphenated. Normal is one of the top 1000 most commonly
spoken and written words. The word normal is normal, it describes itself. But they're also words that are heterological;
adjectives that don't describe themselves.
For instance, the word misspelled. Yes, well, if you don't misspell it.
If you don't misspell it. What about abbreviated? Ooo, I like that one, too. What about German? Not a German word. That's a good one.
How about monosyllabic? That's heterological because it doesn't describe itself.
But polysyllabic? For sure. I especially love just how homological pentasyllabic is. Yeah, five syllables. That is genius. Well, it's the way words are. The way they normally are. But what about you, are you normal? Well, a common way of defining normal is to say that something about you is
normal, if you fall within just one standard deviation of the average for all people. But there are a lot of things about you. You can easily think of, say, 36 different independent variables.
Different things to say about yourself. For instance, how tall you are, how many
friends you have, how bad your breath is or, say, how often you lie. Now, the statistical
probability that you would be normal for all 36 of those different attributes is actually one in a million.
Which means, mathematically speaking, it is quite abnormal to be normal. And as always, thanks for watching.
