All language subtitles for 3_Binary

You might be wondering
how are computers

get these ones and zeros?

It's a pretty question. Imagine
we have a light bulb and

a switch that turns the state
of the light on or off.

If we turn the light on,

we can denote that state is one,

if the light bulb is off,

we can represent
the state as zero.

Now imagine eight light
bulbs and switches that

represents eight bits with
a state of zero or one.

Let's backtrack to
the punch cards

that were used in
Jacquard's loom.

Remember that the loom use
cards with holes in them.

When the loom would
reach a hole,

it would hook to
thread underneath,

meaning that the loom was on.

If there wasn't a hole,

it would not hook the
thread, so it was off.

This is a foundational
binary concept.

By utilizing the two
states of on or off,

Jacquard was able to weave

intricate patterns into
fabric with his looms.

Then the industry started

refining the punchcards
a little more.

Where there was a whole,

the computer would read one,

if there wasn't a hole,
it would read zero.

Then by just translating

the combination of
zeros and ones,

a computer could calculate

any possible amount of numbers.

Binary in today's computer
isn't done by reading holes.

It uses electricity via

transistors allowing electrical
signals to pass through.

If there's an electric voltage,

we would denote it as one,

if there isn't, we would
denote it by zero.

But just having transistors
isn't enough for

our computer to be able
to do complex tasks.

Imagine if you had two light

switches opposite
ends of a room,

each controlling of
light in the room.

What if when you went to turn

on the light with one switch,

the other switch
wouldn't turn off?

That'll be a very
poorly designed room.

Both switches should either
turn the light on or off,

depending on the
state of the light.

Fortunately, we have something
known as logic gates.

Logic gates allow
our transistors

to do more complex tasks like

decide where to send
electrical signals

depending on logical conditions.

There are lots of different
types of logic gates,

but we won't discuss
them in detail here.

If you're curious
about the role that

transistors and logic gates
play in modern circuitry,

you can read more about it in
the supplementary reading.

Now we know how our
computer gets it's ones and

zeros to calculate into
meaningful instructions.

Later in this course,
we're going to be

able to talk about
how we're able to

turn human-readable
instructions into zeros

and ones that our computer
understands through compilers.

That's one of the very
basic building blocks of

programming that's led to

the creation of our favorite
social media sites,

video games, and just
about everything else.