- [Voiceover] The beauty of binary is that it allows us
to use a very elegant form of mathematics.
I'll explain how this works in the next lesson,
which I highly recommend you take the time
to watch through and really understand.
It's not just the elegance of the design though.
There's a fundamental problem computers
have always struggled with:
Reality.
In the real world, things are not always fully OFF or ON.
In fact they're usually mostly OFF, or, mostly ON.
Consider the binary options of light and dark.
In reality, a thing is rarely, truly, all light or dark.
It's usually "quite dark" or "quite bright."
How can a computer decide if a "quite bright" thing
is a one, or a "quite dark" thing is a zero.
In the case of magnetic hard drives, each one or zero,
is stored in its own domain; a little space on the drive
that can be magnetically charged with
the magnetic polarity set one way or the other.
So, set one way, it's a one, and the other way it's a zero.
However, it really isn't exactly
all the way ON or all the way OFF,
rather its 'mostly' ON or 'mostly' OFF.
So probably ON is read as ON,
and probably OFF is read as OFF.
There are only two options; it has to be one or the other.
As long as we're working with something as simple as binary,
the system works pretty well.
It's not flawless,
and there are other more complex systems to correct errors.
But this is easily, enough to understand
the main way technology functions.