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.