Hawking's black hole paradox explained - Fabio Pacucci


Scientists work on the boundaries of
the unknown,

where every new piece of knowledge
forms a path into a void of uncertainty.

And nothing is more uncertain–

or potentially enlightening–
than a paradox.

Throughout history,

paradoxes have threatened to
undermine everything we know,

and just as often, they’ve reshaped our
understanding of the world.

Today, one of the biggest paradoxes in
the universe

threatens to unravel the fields of general
relativity and quantum mechanics:

the black hole information paradox.

To understand this paradox,

we first need to define what we mean
by "information."

Typically, the information we talk about
is visible to the naked eye.

For example,

this kind of information tells us that
an apple is red, round, and shiny.

But physicists are more concerned with
quantum information.

This refers to the quantum properties of
all the particles that make up that apple,

such as their position, velocity and spin.

Every object in the universe is composed

of particles with unique
quantum properties.

This idea is evoked most significantly
in a vital law of physics:

the total amount of quantum information
in the Universe must be conserved.

Even if you destroy an object beyond
recognition,

its quantum information is never
permanently deleted.

And theoretically, knowledge of that
information

would allow us to recreate the object
from its particle components.

Conservation of information isn’t just an
arbitrary rule,

but a mathematical necessity, upon which
much of modern science is built.

But around black holes,
those foundations get shaken.

When an apple enters a black hole,

it seems as though it leaves the universe,

and all its quantum information
becomes irretrievably lost.

However, this doesn’t immediately
break the laws of physics.

The information is out of sight,

but it might still exist within the
black hole’s mysterious void.

Alternatively, some theories suggest

that information doesn’t even make it
inside the black hole at all.

Seen from outside, it’s as if the apple’s
quantum information

is encoded on the surface layer of the
black hole, called the event horizon.

As the black hole’s mass increases,

the surface of the event horizon
increases as well.

So it’s possible that as a black hole
swallows an object,

it also grows large enough to conserve
the object’s quantum information.

But whether information is conserved
inside the black hole or on its surface,

the laws of physics remain intact–

until you account for Hawking Radiation.

Discovered by Stephen Hawking in 1974,

this phenomenon shows that black
holes are gradually evaporating.

Over incredibly long periods of time

black holes lose mass as they shed
particles away from their event horizons.

Critically, it seems as though the
evaporating particles

are unrelated to the information
the black hole encodes–

suggesting that a black hole and all the
quantum information it contains

could be completely erased.

Does that quantum information
truly disappear?

If not, where does it go?

While the evaporation process
would take an incredibly long time,

the questions it raises for physics
are far more urgent.

The destruction of information

would force us to rewrite some of our most
fundamental scientific paradigms.

But fortunately, in science,

every paradox is an opportunity
for new discoveries.

Researchers are investigating a broad
range of possible solutions

to the Information Paradox.

Some have theorized

that information actually is encoded
in the escaping radiation,

in some way we can’t yet understand.

Others have suggested the paradox is
just a misunderstanding

of how general relativity and
quantum field theory interact.

Respectively,

these two theories describe the largest
and smallest physical phenomena,

and they’re notoriously
difficult to combine.

Some researchers argue that a solution
to this and many other paradoxes

will come naturally with a “unified
theory of everything.”

But perhaps the most mind-bending
theory to come from exploring this paradox

is the holographic principle.

Expanding on the idea that the 2D
surface of an event horizon

can store quantum information,

this principle suggests that the very
boundary of the observable universe

is also a 2D surface encoded
with information

about real, 3D objects.

If this is true, it’s possible that
reality as we know it

is just a holographic
projection of that information.

If proven, any of these theories would
open up new questions to explore,

while still preserving our current
models of the universe.

But it’s also possible that those
models are wrong!

Either way, this paradox has already
helped us take another step

into the unknown.

Steve Jobs vs Bill Gates. Epic Rap Battles of History



Let me just step right in

I got things to invent

i'm an innovator baby

change the world

Fortune 500 'fore you kissed a girl

i'm a pimp you're a nerd

i'm slick you're cheesy

beating you is Apple II easy

I make the product

that the artist chooses

and the GUI that Melinda uses

I need a bring up some basic shit

why'd you name your company

after your dick?

You blow, jobs

you arrogant prick

with your second hand jeans

and your turtleneck

I'll drill a hole in the middle

of your bony head

with your own little spinning

beach ball of death

Hippie

you got given up at birth

I give away your net worth

to AIDS research

combine all your little toys

and i still crush that

iPhone? iPad? iPwn? iSmack

a man uses the machines you build

to sit down and pay this taxes

a man uses the machines i build

to listen to the Beatles

while he relaxes

well Steve

you steal all the credit

for work that other people do?

did your fat beard Wozniak

write these raps for you too?

Ooo

Everybody knows Windows

bit off Apple

I tripled the profits on a PC

all the people with the power to create

use an Apple

and people with jobs use PC

you know i bet they made

this beat on an Apple

nope, Fruity Loops

PC!

you will never

ever catch a virus on an Apple

well you can still afford a doctor

if you bought a PC

let's talk about doctors

I've seen a few

cause i got a PC

but it wasn't from you

I built a legacy son

you could never stop it

now excuse me

while I turn heaven a profit

fine!!!

you wanna be like that

die then!!!

the whole world loved you

but you were my friend

I'm alone now

with nothing but power an time

and no one on earth

who can challenge my mind

I'm a boss!!!

I own DOS!!!

your future is my design!!!!!

I'm a God!!!!!

own Xbox!!!!!!!!!

now there's no one can stop me

the world is mine!!!!!!!!!!!!!!!!!!!

I'm sorry Bill

I'm afraid I can't let you do that

take a look at your history

everything you built leads up to me

I got the power of a mind

you could never be

I'll beat your ass in chess

and Jeopardy

I'm running C plus plus

saying hello world

I'll beat you til you're singing

'bout a daisy girl

I'm coming out the socket

nothing you can do can stop it

I'm on your lap and in your pocket

how you gonna shoot me down

when I guide the rocket?

your cortex just doesn't impress me

so go ahead try to Turing test me

I stomp on a mac and a PC too

I'm on Linux bitch

I thought you GNU

my CPU's hot

but my core runs cold

beat you in seventeen lines of code

I think different from the engine

of the days of old

hasta la vista

like the Terminator told ya

Nikola Tesla vs Thomas Edison. Epic Rap Battles of History

step up

you’ll be shocked

when I spit and start static

I’ll rip your style and add it

to my long list of patents

while you were busy

digging ditches

and burning bridges

I’m pumping out inventions

stacking riches

so go back to your pigeons

you’re a geek

plagued by OCD

you never had sex

but you sure got screwed by me

I’ll crush you Tesla

there’s just no putting it gently

I don’t alternate my flow

I diss you directly

I see a universe of infinite energy

but no potential for threat

from this enemy

so you can call me Tesla

Nikola

impeccably dressed

giving lessons in electrical nemesis

this will be on the test

so confess

to your thefts

and let the whole world know

what the Serbian did

for the Wizard of Menlo

history is getting rewritten

and I have reddit

your best invention

was a way to steal credit

the truth hertz

you’re broke and washed up

don’t give a smidgen

‘bout your visions

if they can’t make a buck

I conduct business

understood

things you never could

so dope

that I even make New Jersey look good

I’m on the record I invented

you got duped there I said it

and I’ll bet you 50 thousand dollars

that you’ll never forget it

without me

here’s a taste

of what this battle would be

no lights

no camera

no sound

see?

you fool

you think that you can

touch me with this?

you couldn’t handle my gifts

with your greedy little mind

what’s inside mine

was ahead of it’s own time

you did not steal from me

you stole me from mankind

it’s a wireless transmission of truth

and it’s a shocking real story

of a banker and you

and if the people knew

you stopped me from making power free

they would curse

the con Edison with every utility

who won?

who's next?

you decide


The Rise Of The Drive-Thru

When drive-thrus first became a thing
in the 1950s, they brought together

two of American's favorite things:
cars and fast food.

Drive-thrus were essentially developed to
make fast food even faster.

Experts estimate that about 60-70 percent
of a restaurant's sales come

from the drive-thru, if
they have one.

That means nailing customers'
experience there is essential.

We're doing a number of things to make
sure that not only is it fast, not

only is the food delicious, but also to
make sure we get your order right.

Drive-thrus have been undergoing transformations
as restaurants turned to

technological solutions to
boost sales.

Companies are pouring money into
innovations like digital menu boards,

dual-lane drive-thrus and even artificial
intelligence to get diners to

spend more. And it's working.

Drive-thrus represent a huge chunk of
restaurant sales and more people

than ever are using them.

In 201 9, 39% percent of consumers
reported they use the drive-thru more

often than they did the year prior.

Despite the surge in popularity, just
20 percent of American restaurants

currently have a drive-thru.

In a segment with razor thin
margins like fast food, providing solid

drive-thru service can be
make or break.

In the 1920s, the number of people
who owned cars in the U.S.

exploded. In these pre-depression years,
people were making more money,

and everyday-consumers could afford
to buy a car.

Over the next few decades, drive-in
restaurants and drive-in movies took

off. At drive-in restaurants, customers
would drive into a restaurant's

parking lot, park their car and order
from a waiter or waitress called a

car hop. Car hops delivered food
to people sitting in their cars.

Those restaurants where the
predecessor to drive-thrus.

Then banks started rolling out drive
-thrus in the 1930s, so that

customers carrying big sums of cash didn't
have to wait on the street.

It didn't take long for
fast-food restaurants to catch on.

Drive -thru dining first became a
thing in the 1950s in California.

But it didn't go mainstream until
the 70s, when major fast-food

restaurants across the country began adding
drive -thru windows to their

restaurants. With more single parent
households after school activities

for kids, and women working outside the
home in the 70s, convenient fast

food became more and more attractive,
according to the National Museum of

American History. In-N-Out has long
been a drive -thru trendsetter.

At the California burger chain, customers
were given butcher paper to

shield their laps from spills
while eating in the car.

In-N-out has what's considered one
of the best drive-thru experiences

today. In-N-Out drive -thrus also
developed now commonplace elements of

the drive thru experience.

The company says it invented the
two-way speaker system for drive-thru

ordering. Some of the most popular
fast-food chains have drive-thrus to

thank for strong growth.

For instance, Wendy's started adding
drive-thru windows in 1971, and

restaurant experts credit them as one
factor behind Wendy's fast expansion

in the years that followed.

Drive -thrus saved Wendy's space in
its parking lots and indoor seating

areas because the drive-thru customers
usually left and eat somewhere

else. McDonald's built its first
drive -thru in 1975.

Most national fast-food chain had
drive-thrus by the mid 70s.

Fast-food restaurants also started developing
more products that could be

eaten easily in a car.

According to one fast-food historian,
Chicken McNuggets were developed

with driving in mind.

And it wasn't just the fast-food
chains that were adapting the sales

experience to be as convenient
to customers as possible.

As eating in the car grew
in popularity, automakers also took notice.

By the 1960s, glovebox doors
opened flat to support drinks.

And in the 80s, built-in
cup holders were standard issue.

The number of cup holders in a car
has even become a selling point for

manufacturers. Subaru's Ascent SUV made
headlines for sporting 19 cup

holders. Drive-thrus have even started to
catch on with restaurants that

have long avoided the format.

Fast casual chains like Panera and
Cava resisted the drive-thru model for

years, but QSR magazine
says that's changing.

Some of the biggest names in fast
casual are adopting the model and

showing that the drive -thru can be
compatible with food that takes a

little longer to prepare.

There's no question that the
drive-thru is uniquely American.

There's even a national drive-thru day
celebrated every July 24th in the

U.S. The drive-thru has spread
to other countries, too.

But experts note they're most popular
in places that share some

similarities with the U.S.—low

population density and a
car centric culture.

Think places like Saudi Arabia, the
United Arab Emirates and Australia.

McDonald's Ireland claims to have brought
the very first drive -thru to

Europe when it opened in a
Dublin shopping center in 1985.

It was soon rebranded as McDrive.

All around the world, McDonald's
drivers have different names.

In Spain, they're called McAuto.

And in Chile and
Paraguay, you'd visit Auto-Mac.

There's even a McSki in Sweden where
customers can pick up Big Macs and

McFlurries after a day on the slopes.

The drive-thru isn't particularly popular in
Asia, which has less driving

culture and cities with
high population density.

In jam-packed cities, fewer people have cars
and real estate for a big

drive -thru is expensive.

In South Korea, Singapore and Japan
in particular, take out from quick

service restaurants is common, but a
small portion of those orders take

place in the drive
-thru, according to Technomic.

There are some countries that are hardly
showing us much of anything at

all, such as Japan, for example, where we
have only about a fifth of those

takeout orders that
are drive through.

What do we have in Japan? We
have a very concentrated population, right?

As the drive -thru has become
an essential revenue stream for fast-food

chains, it's continued to dictate what
products they develop and where

they build restaurants. Here's how
restaurants are bringing drive-thrus

into the 2020s.

There are a lot of factors that
go into a customer's experience at the

drive-thru. Order accuracy, customer-service
and cleanliness all determine

a consumer's experience
at the drive-thru.

It's not all about speed.

In fact, the amount of time customers
spent in the drive-thru actually got

longer in 2019 when compared
to the year prior.

But customers didn't seem to
care all that much.

Take Chick-Fil-A. It has the longest service
speed, but it comes out on

top in accuracy and customer service.

Despite the drive-thru service, Chick-Fil-A
actually has incredibly loyal

customers, and their customers don't think that
their wait time is long ,

which is an interesting
aside to that.

So while they have the longest time,
people are going to go there anyway.

Fast-food chains see a big opportunity
in improving how customers order.

Menu boards are more complicated
than you might expect.

There are certain ways to arrange
products and highlight promotions that

will encourage customers
to spend more.

Fast food-restaurants are designed to be
quick, but sometimes that speed

of service in line or at the drive-thru
can end up being stressful for the

consumer. And stressed customers
may order less.

So fast-food operators think pairing technology
with menus can help solve

the problem. There's a science behind it, but
it's also a bit of an art.

So designing the menu board in the
right way can really help leverage

investment and drive returns more than,
more than some people may realize.

There's an industry shift to using
digital menu boards which can be

updated faster than printed menus.

Digital signs can help restaurants rotate
menus for breakfast, lunch and

dinner and remove products
that are sold out.

Restaurants that had digital menu
boards made service speedier and

customers do care about their menus.

In a 2019 survey, 74 percent of customers
said an easy to read menu board

is a top priority.

But digital menu boards were president
at less than 20 percent of

drive-thrus. In the survey, McDonald's had
the most digital menu boards in

place by far, with 60.6

percent. McDonald's is making huge
commitments to improving menu boards.

In March 2019, it bought a tech
company called Dynamic Yield, which uses

artificial intelligence to personalize digital
menu boards based on

factors like the weather
and restaurant traffic.

Let's say it's a sunny day, menu boards
enhanced with AI might show you an

ice-cream cone or iced-coffee at
the center of the board.

For some customers, that
makes choosing easier.

It's also helped McDonald's too.

Former CEO Steve Easterbrook said on
a call with analysts, that adding

Dynamic Yeild's technology to outdoor
digital menu boards is increasing

how much customers spent.

Some chains are also experimenting with
license plate recognition to speed

up drive-thru times and
sell more to customers.

Here's how it works: A camera reads the
license plate on a car in the

drive-thru, compares it to information
in a restaurant's database, and

finds that customers ordering history
and credit card details.

That allows the restaurant to target menu
items to the customer and use

saved payment methods.

That technology isn't being used on a
national scale, but it suggests what

could be ahead in
drive -thru innovation.

Before you even get to the
point of ordering your food, fast-food

restaurants have to convince
customers to choose them.

Restaurant experts say sometimes a crowded
drive -thru is enough to turn

customers away. To fix congestion in
the drive -thru, the physical format

of fast-food restaurants
is changing too.

More restaurants are
building dual-lane systems.

Sometimes it's just two typical
drive, order and pay lines.

At other restaurants, there's one traditional
lane and then a second

special lane for customers who already
placed and paid for their order

online, and are just coming
to pick up their food.

Dunkin', Chick-Fil-A, McDonald's and others are
testing this kind of dual

drive -thru system. But while restaurants
intend to make the drive-thru

more efficient, research has shown
dual drive -thrus don't necessarily

speed up service. That was a bit surprising
to us when we sliced the data

last year, and we found that it
didn't necessarily speed up an individual

customer's time in line, but it may
increase the overall throughput for a

restaurant. So that's not to say that
it's not a good investment, because

it might be, but it doesn't
always speed up, again, an individual

customer's experience there.

Restaurant experts say that while dual drive
-thrus may not speed up the

process... Hi there, got
a mobile order?

Mobile ordering on its own can
succeed in reducing a customer's ordering

stress and increasing efficiency.

Ordering through an app
can also improve speed.

At Chipotle, service times are as low as
11 seconds at its version of the

drive-thru called Chipotlanes.

There's two parts of the of the
process when you go through a traditional

drive -thru, that you don't
have to do at Chipotlane.

And there 're really two of
the slowest parts of the experience.

One is ordering, so not only do you
not have to order at Chipotle, you

order ahead on your phone. So the
ordering process has already been taken

care of and the
payment process as well.

Those are the two things in a
drive-thru that tend to cause the drive-thru

to stack up. And that's what
c auses the wait times.

The app also tries to reduce
slow service times during busier periods.

At Chipotlanes, if a restaurant has a
lot of orders coming in at once,

Chipotle will suggest another time for
pickup, so customers don't have to

wait as long. For instance, the app
might suggest you pick up a lunch

order for 12:30 at 12:45 instead.

By the end of 2019, Chipotle had
66 Chipotlanes around the country, and

plans to add more. Chipotle had a
strong fourth quarter of 2019 with

digital sales-growth of 78.3

percent and same-store
sales-growth of 13.4

percent. And some restaurants are literally
going all in on the

drive-thru. KFC opened a drive-thru only
restaurant in Australia in 2019,

the first of its kind.

Customers order on the KFC app and
enter a four-digit code onto a

touchscreen receiver, which transmits their
order to the kitchen.

The drive-thru has five lanes, three
of which are for online pickup.

I wouldn't be surprised to see
more smartphone technology and more

ordering capabilities go
into the car.

Domino's is starting to play with
this, as a matter of fact.

The drive-thru used to be the
most convenient way customers could get

their fast food. Third-party delivery apps,
like GrubHub and Uber Eats,

have disrupted that in the 2010s.

Now food from popular chains like
McDonald's and Tripoli can come straight

to your door. Some restaurant experts
say that's a threat to the

drive-thru. The rise in third-party delivery
apps is one of the biggest

disruptions in fast-food this decade.

In 2018 alone,
consumers ordered $10.2

billion dollars worth of food
from third party delivery services.

That size would make the third-party
delivery market the fifth largest

U.S. restaurant chain.

But as consumers embrace the ease
of ordering through apps like GrubHub

and Uber Eats, restaurants are grappling
with how delivery services impact

their bottom line. On one hand,
third-party delivery apps may boost the

number of customers chains like
McDonald's and Chipotle reach.

On the other hand, restaurants have to
share some of the profits from

orders with third-party
delivery services.

Delivery providers charge restaurants a
fee of 15-30 percent for

fulfilling orders, eating
into restaurant's profits.

Given over the last three years or
so, the advent of the third-party

delivery companies, and being able to order
your food on your own and walk

inside and pick it up, all of
the other channels available to people to

get their food, the drive -thru
has seen an incredible amount of

competition. In some cities, Drive-thrus are
just fighting to stay open.

Cities across the U.S.

are banning the construction
of new drive-thrus.

Places in Missouri, California, New
Jersey and Minnesota have implemented

bans restricting drive-thrus.

These policies aim to improve safety
and walkability in cities and reduce

pollution and trash.

They also want to
encourage healthier eating.

Some research has pointed to
the possibility that legislation curbing

drive-thrus promotes
healthier eating.

A study of 27 Canadian cities
with fast-food bans found that fast-food

drive-thru service bans may play a
role in promoting healthier food

environments. Though it was short lived,
in 2008, South Los Angeles was

one of the first places in the U.S.

to ban construction of new
fast-food restaurants, including drive-thrus.

The city stopped the construction of
new fast-food restaurants to address

higher than average obesity rates.

A few years later, in 2015, the Rand
Corporation did a study on the impact

of the 2008 ban and found that
obesity actually increased in the area.

Although the number of soft
drinks consumed per person fell.

The study concluded that residents had
other places to find unhealthy

food, like convenience stores, and that
focusing on reducing portion sizes

might have been more effective.

Experts say, bans like this
won't kill the drive-thru.

Third-party delivery apps aren't
likely to either.

I would say that the drive-thru
has a very bright future, whereas

deliveries future is at this point
seems somewhat questionable when we

talk about third-party, and that really
has to do with the economics

behind it. Nearly 40 percent of
consumers reported they're using the drive

-thru more often. This spike is part
of a bigger shift, eating off

premise, away from a restaurant.

Customers want to take
their food and go.

To stay competitive, chains have to
make eating outside the restaurant

easy and fast.

And that's where the
drive-thru really delivers.

The myth of King Midas and his golden touch - Iseult Gillespie


With his harebrained schemes 
and asinine dealings with the gods,

King Midas ruled the ancient kingdom 
of Phrygia with an uneven hand.

He was known in Greek mythology 
as a rogue ruler

whose antics bemused his people 
and distracted the gods.

Midas spent his days 
in a stupor of splendor,

spoiling himself and his beloved daughter
and gorging himself on feasts and wine.

Unsurprisingly, he felt 
an affinity with Dionysus,

god of wine, carnival, and performance.

One day, Midas discovered a satyr

dozing in his rose garden and drunk 
on more than the scent of flowers.

Midas recognized the satyr 
as one of Dionysus’s followers

and let him nurse 
his hangover at the palace.

Pleased with the king’s hospitality,
Dionysus offered to grant him one wish.

Midas cast a greedy eye 
over his surroundings.

Despite the luxury in which he lived,

no amount of precious jewels, finest silk 
or splendid decor felt like enough.

His life, he thought, was lacking luster;
what he needed was more gold.

The god sent the power to turn anything
the king touched to gold

surging through Midas.

Ecstatic, he turned to his possessions.

At his lightest touch, 
the palace walls transformed,

stone statues shone,

and goblets glittered.

He galloped through his home in a frenzy,

handling each item until 
it took on a lustrous sheen.

Soon the palace heaved with gold,

and Midas’s delirious
laughter echoed off the walls.

Exhausted and hungry from his rampage,

Midas picked up a bunch of grapes from 
his newly gilded fruit bowl.

But he nearly shattered his teeth,

for the fruit had turned 
to metal in his mouth.

When he picked up a loaf of bread, 
the crumbs hardened in his hand.

Flinging himself onto 
his bed in frustration,

Midas discovered his plush pillows 
had morphed into solid gold.

Hearing his cries of frustration, 
his daughter entered the room.

But when Midas reached out to her,

he saw with horror that he had frozen her 
into a golden statue.

Horrified at what he had done,

Midas begged the gods 
to rid him of his power.

Taking pity on the foolish king,

Dionysus told Midas to wash 
his hands in the River Pactolus.

When Midas reached into the river, 
the gold drained from his fingertips.

Midas returned home 
to find his daughter alive

and his palace back to normal, 
and he rejoiced.

You’d think he would’ve learned 
his lesson,

but just a few weeks later,
Midas blundered again,

insulting the music and sun god Apollo 
when he declared Pan a greater musician.

Apollo scornfully declared that the king 
must have the ears of an ass

to make such a misjudgment,
and transformed Midas accordingly.

Once again regretting his behavior,

Midas kept his hairy ears 
hidden in public.

They were seen only by his barber,

who was sworn to secrecy during 
a very awkward grooming session.

The barber stifled his laughter 
and fought the desire to tell someone,

yet the secret consumed him.

One day, he walked outside the city 
and dug a hole in the ground.

Plunging his head into the earth,

the desperate barber whispered,
“Midas has ass’s ears.”

Soon after, a clump of reeds sprang up

in the spot where the barber 
had buried his words.

When the wind blew, they carried the 
echoes of his whisper through the breeze:

"Midas has ass’s ears."

At the sound, donkeys in the fields raised
their heads in recognition

and people chuckled to themselves 
at the follies of their king.

With his golden touch and ass’s ears, 
Midas was not the most respected ruler.

And where other leaders were honored 
through statues and temples,

his people remembered him 
a little differently:

in the depths of the glittering river 
and the rustle of the Phrygian wind.


Can you solve the troll’s paradox riddle? - Dan Finkel

You’ve discovered a doorway
to another realm,

and now you and your brother

are off exploring the wonderful
world of Paradoxica.

Fantastically paradoxical creatures crawl,
run, and fly around you.

And then you see the troll.

It’s catching all the creatures
in an enormous net.

You bravely step forward
and demand it let them go.

The troll laughs.

“If you’re such a
fan of paradoxes,” it says,

“then I’ll make you an offer.

If you say something true,
I’ll release all these creatures."

You’re about to say, “You are a troll,”

but before you can,
the troll grabs your brother.

“If you say something false,”
he continues,

“then I’ll release your brother."

Your statement can
only be a single sentence.

And as you can see,
I hate paradoxes more than anything.

If you try to cheat
by saying something paradoxical,

like, ‘this statement is false,’

then I'll eat your brother
and the creatures."

What true/false statement
can you say to force the troll

to free your brother
and the paradoxical creatures?

[Pause the video now if you
want to figure it out for yourself!]

Answer in: 3

Answer in: 2

Answer in: 1

This seems like an impossible situation,

but incredibly, you can say something

that will force the troll to
release all its prisoners.

This is an example of coercive logic,

invented by the great logician
and puzzle creator Raymond Smullyan.

The trick Smullyan came up with
involves saying a statement

whose truth or falseness depends on
what you want the troll to do.

Your statement still
has to be carefully crafted.

For example, if you were to say,

“You are going to free the
creatures and my brother,”

the troll could respond, “that’s false…
I’m only going to free your brother.”

Similarly, if you said, “You will free
the paradoxes,”

the troll could say, “That’s true,”
and free the paradoxes.

But watch what happens if you say,
“You will free my brother.”

The statement can’t be false,

because if it were, the troll,
by its own rules,

would have to free your brother.

That would make the statement
paradoxically true and false.

But the troll hates paradoxes

and would never willingly create one.

So his only option
is for the statement to be true.

If “you will free my brother” is true,

then the troll
has to release your brother.

And by its own rules, the troll
has to free the creatures as well,

since you said a true statement.

By wielding just 5 words
like a logical scalpel,

you’ve forced the troll
to free all its prisoners.

As the troll stomps off in anger,

the paradoxes cheer you
for winning them their freedom,

and promise to lead you to the
treasure at the top of the stairs.

If you can reach it.

Everything changed when the fire crystal got stolen - Alex Gendler





Someone has tripped the magical alarms
in the Element Temple.

By the time you and the other monks
arrive on the scene,

you know you have a disaster
on your hands.

Overnight, four young apprentices
broke into the temple’s inner chamber

to steal the sacred element crystals.

But when the alarm went off
they panicked,

and each of them swallowed the crystal
they held right before they were caught.

With no idea how to control
the crystals’ vast powers,

they’ll soon transform
into uncontrollable elemental spirits.

Improbably enough,

the old monk next to you
has seen something similar happen before.

He explains:
“You must determine who ate which crystal

and get each into the proper containment
field before they transform.

The elements compel their masters:

those who ate the Earth and Water Crystals
must speak the truth,

while those who consumed Fire and Air
must lie."

The youths are too scared to confess
their own transgressions.

Instead, they fall to accusing each other.

“Rikku took the Water crystal!”
Sumi blurts out.

Rikku interrupts angrily.

“It was Bella,
she stole the Fire crystal!”

So Bella yells:
“Jonah ate the Air crystal, I saw him!”

Jonah looks up timidly
and shakes his head.

“I… I don’t know what happened,
but Sumi doesn’t have the Earth crystal.”

So who ate which crystal?

Pause now to figure it out for yourself.

There’s no getting around it—
this will take some trial and error.

But that’s not a bad thing.

If we make a wrong guess,

we’ll eventually reach a point where
our conclusions contradict each other.

That would allow us to confirm
that our initial guess was wrong

and work from there.

This is a technique
known as proof by contradiction.

The trick is in being strategic
about where we begin our guessing.

Some assumptions
might not lead to contradictions

without making further assumptions.

We want to pick one that creates
the most constraints on its own,

and thus gives us the most information
when it turns out to be right or wrong.

Take, for example, Sumi’s statement.

If we assume she’s telling the truth,

we’d know the identity
of both truth tellers.

Rikku would have the Water crystal,
and since she’s not lying about him,

Sumi would have Earth.

So Bella would have the Fire crystal,
as Rikku says.

But then Bella would have to be lying
about Jonah having the Air crystal.

And yet that’s the only remaining option.

This is a contradiction, and it tells us
our initial assumption was wrong.

So now we can go back to the start,

but with the added knowledge
that Sumi is lying.

As a liar, Sumi
must either have the Fire or Air crystal.

That means Jonah
was telling the truth about her,

so he can’t have taken either of those.

And that means Bella was lying about him,

so she must also have either Fire or Air.

Since Sumi was lying,
Rikku can’t have taken the Water crystal—

the only one left
who could have it is Jonah.

And because we’ve already identified
the two liars,

Rikku must have the Earth crystal.

That means Bella has the Fire crystal
and Sumi has Air.

You manage to get them all
in the proper containment fields

just as the crystals’ magic
begins to manifest.

Compared with the difficult task
of training these kids

to control their new powers,

figuring out who had which crystal
was elementary.

 

Wonder Woman vs Stevie Wonder. Epic Rap Battles of History

Epic Rap Battles Of History


Wonder Woman


VERSUS


Stevie Wonder.


BEGIN!


Wonder Woman fly


I’m about to tell you why


Princess Diana but this lady don’t die


my rhymes are signed, sealed


and delivered on time


you a bald has-been, I’m in my amazon prime!


I’ll tell you what I say


you bit your style from Ray


the grin and the shades


and the King Cobra head sway


Gods made me out of clay


then they broke the mold


I’m like Gina Davis, in a justice league of my own


I just called to say


that you need to ditch the hair beads


lookin like the Predator


aften some chemotherapy


but don’t be scared


I let bats down easy


so you don’t gotta worry ’bout a thing Little Stevie


I feel like this is the beginning


but you have sucked for


a few thousand years


I’m a man who comes from a higher ground


and I say DC is a whole step down


I’ve been spitting out hits


since both Fingertips


so use the tip of your fingers


and read my lips


how you gonna talk about a bat being blind?


you need to echo-relocate to the fourth of luly


because you’re MS. Independent


or at least you try


but your first story is you


running off with a guy


now let me tell the truth


cause I know you got the lasso


you got that wack flow


Suffering Sappho!


I"m the ceremony master


blaster with the bars


and I got more grammys


than your panties got stars


Well I’m a woman who wonders


what you’re thinking


some of your records


make me wish you started drinking


even if I stick to the best selections


your Youtube videos


raise some vision questions


Your ignorant questions


could never cause as much pain


as never knowing


how stupid you look in your airplane


you’re a misguided C-minus


on the Bechdel test joke


and my worst song is better


than your best TV show


Look I don’t want to judge a Talking Book


by its cover


but of the vegan buffet


you’re a Full Time Lover.


and part time father


from what I’ve discovered


9 ditferent kids


with 5 ditferent mothers


you couldn’t walk in my shoes


so stick to your re boots


with plots so thin


even I can see through


It’s not a superstition


I believe you got dissed


not even your tiara’s


coming back trom this (haha)