Welcome back to the Deep Dive. Today, I want
you to picture something really specific. Okay,
what are we picturing? Picture a black screen,
a blinking cursor, and you are staring at it,
about to type the very first thing into a totally
new system. I know exactly where this is going.
Right. It's a ritual that is so ingrained in
the technological world that we almost never
stop to ask why we do it. It's usually just two
words, maybe a comma, and almost always an exclamation
mark. Hello, world. Exactly. The most famous
phrase in computing. If you have ever tried to
learn to code, whether it was Python last week
or basic 30 years ago, this was almost certainly
the very first thing you built. Oh, without a
doubt. And it seems deceptively simple. You type
a line, the screen talks back to you. Mission
accomplished. It feels simple, sure. But that
simplicity masks a massive amount of complexity.
Hello, world isn't just a greeting. It's a historical
artifact. It's a rigorous stress test for your
entire system. And in many ways, it's the fundamental
handshake between human and machine. And that's
the mission for this deep dive. We aren't just
looking at the syntax or how to type the code.
We are going to unpack the history, which involves
everything from Bell Labs to a 1950s radio DJ.
And we're going to look at why, 50 years later,
this is still the default sanity check for millions
of developers. It really is the cultural baseline
of the entire industry. It's the one thing almost
every programmer has in common, regardless of
what language they speak or what era they grew
up in. So let's start with the definition, just
so everyone is on the same page. same page. When
we say a hello world program, strictly speaking,
what are we actually talking about? At its core,
it is the absolute simplest valid program you
can write in a given language that produces a
side effect. A side effect meaning? Specifically,
outputting that text to a display device, usually
the console. It does nothing else. It doesn't
calculate. It doesn't take input. It just speaks.
It just screams into the void and the void answers.
Now, I think most people, myself included, assume
this phrase just sort of emerged like it was
always there. But looking at the sources we have,
there is a very specific lineage here. We can
trace it back to one specific book. We can. The
moment it solidified as the tradition was 1978.
That's when Brian Kernighan and Dennis Ritchie
published the C programming language. Which is
known as KNR. Right, KNR. It is basically the
Bible of computing. C is the ancestor of almost
all modern language. You know, C++, Java, Python,
they all owe amounts of debt to C. Yeah. In that
book, the very first example Kernighan used to
show how the language worked was a program that
printed hello, world in all lowercase. And because
everyone learned from that exact book, everyone
just copied the example, it became the default.
Precisely. It became a meme before we even really
had the word meme. Right. But, and this is where
the history gets murky and really interesting,
Kernighan didn't actually invent it for that
book. He was recycling his own material. This
is the part I found fascinating in our research.
We have to go back further into the depths of
Bell Labs in the early 70s. Right. If you dig
into the internal memos of Bell Labs, you find
a tutorial from 1974, also by Kernighan, called
Programming in C, A Tutorial. The phrase is right
there. But if you keep digging, you hit 1972.
Yes. 1972. Before C, there was B. The language
era. Exactly. And Kernighan wrote a tutorial
introduction to the language B. That is the earliest
documented instance we have of code being used
to print hello world. But the context in the
B tutorial was totally different, wasn't it?
It wasn't just a friendly say hi exercise. It
was solving a pretty weird technical problem.
It was. This is a great example of how hardware
limitations actually shape our culture. So the
B language had a quirk. It stored text and variables,
but those variables were bound by the physical
architecture of the computer they were running
on. Which was usually what back then? Usually
something like a PDP -7. A variable in B could
only hold four ASCII characters at a time. Four
characters. That's it. That's it. So you couldn't
just say print hello world. The variable memory
wasn't big enough to pull the whole sentence.
So how did he actually get it to print? He had
to chop it up. The code example was actually
demonstrating how to string together external
variables. Oh, wow. Yeah. One variable held heli,
the next held O comma space W, the next ORLD,
and so on. That is wild. So the Hello World tradition
didn't start as a greeting. It started as a hack
to show how to glue string fragments together
because the computers were literally too weak
to handle the whole phrase at once. Exactly.
It was a demonstration of managing memory constraints.
We've kept the phrase, but we've largely forgotten
that the original lesson was about the limitations
of the hardware. Now, speaking of the phrase
itself, why Hello World? Why not just test or...
It works. Yeah. This brings us to the really
unlikely connection to a New York radio DJ. Right.
William B. Williams. I love this detail because
it takes us out of the computer lab entirely.
So Williams was a DJ on WNEW in New York in the
1950s. And he had this signature sign on. He
would turn on the mic and say, hello, world.
And Kernighan has admitted in interviews that
this was likely rattling around in his subconscious.
He remembers seeing a cartoon of a chick coming
out of an egg saying it. or hearing it on the
radio. So it wasn't on purpose? It wasn't a deliberate,
I am quoting this DJ moment, no. But it shows
that computer science doesn't happen in a vacuum.
The pop culture of 1950s radio totally seeped
into the sterile environment of Bell Labs. It
adds such a human texture to it. Every time a
new kid in a coding boot camp types that line
today, they are unknowingly echoing a 1950s radio
bit. It's a really nice reminder that code is
written by humans. Although, to be totally thorough,
I should mention the jargon file claims a 1967
origin with the BCPL language. Okay. But the
Kernighan lineage at Bell Labs is the one we
can actually prove with physical paper trails.
Fair enough. So, we know where it comes from,
but we don't use the B language anymore. We don't
have four character limits on our variables today.
Why does this persist? Why is it still the very
first step? This brings us to the concept of
the sanity check. I hear this term used a lot
by engineers. Let's do a sanity check. What does
it actually imply in this context? Think about
what actually needs to happen for code to run.
When you sit down at a computer and type print
hello world, you aren't just typing words. You
are activating a massive invisible industrial
pipeline. It feels instant to me though. I hit
run and the text just appears. It feels instant,
but physically it's a miracle. How so? Well,
you need an editor to accept the text. You need
a compiler to translate that text into machine
code, the binary that the processor can actually
understand. You need a linker to grab the standard
library so the computer knows what print even
means. Right. You need the operating system to
give you permission to access the screen. And
finally, the hardware driver has to literally
light up the pixels. Okay, so it's huge chain
reaction. It's a Rube Goldberg machine. Yeah.
And if any single part of that chain is broken,
if the compiler is the wrong version, if the
path variables aren't set, if the permissions
are wrong, the program crashes. So Hello World
isn't testing my ability to code. It's testing
the environment. Bingo. It validates the workflow.
If Hello World fails, you don't have a coding
problem, you have a configuration problem. That
makes so much sense. It saves you from debugging
a really complex algorithm when the issue is
actually just that you didn't install the language
correctly. It's like tapping the microphone before
you start singing. You aren't testing your voice.
You're testing the sound system. That's the perfect
analogy. In fact, this utility is so universally
recognized that Linux systems, specifically Debian
and Ubuntu, have formalized it. I saw this in
the notes. There is a literal package called
simply hello. Yes. You can type apt -get install
hello. It downloads a program from the GNU project
that just prints a friendly greeting. Why would
anyone ever need to download that? It's not for
the user to say hi. It's for the developers.
It serves as the sanity check for the package
manager system itself. Oh, I see. It's a perfect,
compliant example of how to structure a software
package. If you were building a new installer
or package manager, you test it with Hello, because
you know the code itself is totally bug -free.
So if it fails... If it fails, you know your
installer is broken. It's the control group of
the experiment. Exactly. It's the stable baseline.
I want to pivot to something that I think is
really useful for anyone looking at picking up
a new language. There is this metric we came
across called TTHW. Yes, the time to hello world.
It sounds like a race. It effectively is. It
measures approachability. The stopwatch starts
when you sit down to learn a language, and it
stops when you successfully see text on the screen.
Okay. It is a fantastic way to judge how scary
or complex a programming language actually is.
So let's compare a few to get a feel for this.
Let's look at the easy end of the spectrum first.
Python. Python is the absolute king of low TTHW.
You install it, you open a file, and you type
print hello world. One line. No boilerplate,
no complex setup. So the barrier to entry is
basically zero. Right. It's designed to be readable.
It wants you to succeed immediately. Now contrast
that with C++. C++ is notoriously not that. C++
is industrial grade. To say hello, you can't
just say print. You need to include a library
called Iostream. You need to use a namespace.
You have to declare a main function because C++.
demands to know specifically where the program
starts. Wow, that's a lot. And you have to use
standard count and insertion operators, those
little angle brackets, and you usually need to
return an integer at the end to tell the operating
system, I finished correctly. That is a massive
amount of overhead just to say hi. It is, but
it teaches you something fundamental about the
language. It tells you that C++ gives you manual
control over everything. Input streams, memory,
exit codes. So high TTHW usually means high power,
high complexity. Exactly. It forces you to understand
the structure before you get the reward. And
then there's Go. The notes mention Go does something
pretty interesting with its Hello World. Go is
a modern language from Google. Their tutorial
example doesn't just print English. It prints
English, Chinese, and Japanese characters all
at once. Total show -offs. A little bit. But
it's highly strategic. They are demonstrating
that Go has Unicode support built right into
the core. Why is that a big deal? In the old
days, like with C, handling foreign characters
was an absolute nightmare. Go is saying... Look,
we are modern. We handle the whole world right
out of the box. No, we have to talk about the
absolute nightmare scenario. The time to hello
world champion of the universe. Malbolge. Ah,
yes, Malbolge. Wade, I'd never heard of this
until we looked at these sources. The TTHW was
two years. That is correct. Two entire years.
How is that even possible? Malbolge is what we
call an esoteric programming language. It wasn't
designed to be used. It was designed as a challenge.
Or maybe a sick joke. The joke. It's named after
the eighth circle of hell in Dante's Inferno.
The entire design goal was to make it as difficult
as possible for a human being to write code.
So what makes it so hard? Is it just weird symbols
or what? It's much worse than that. The commands
actually change depending on where they are in
memory. Wait, really? Yes. The code modifies
itself as it runs. The logic is ternary, so base
three rather than binary. It is completely hostile
to human reasoning. So the two -year delay, that
wasn't just someone procrastinating. That was
someone actively trying to figure it out. It
took two years for the very first valid Hello
World program to appear. And here's the kicker.
A human didn't even write it. Really? Who did?
A cryptographer had to write a completely separate
program in Lisp, which is a smart logical language,
to search through the combinations and basically
discover the Malbolge code that would output
the right text. So it was brute forced by another
computer. Yes. That is the ultimate irony. The
language is so hard that we literally needed
machines to talk to it for us. And the output
wasn't even perfect. It printed Hello World with
totally weird capitalization. Because that was
the absolute best the search algorithm could
find. That's fantastic. It's the hello world
from hell, literally. Literally. So we've talked
a lot about text, but we are moving into a world
where not everything is a command line. What
happens to hello world when you don't even have
a screen? This is where the concept adapts beautifully.
It turns out, hello world isn't actually about
text. It's about the simplest possible output.
If you are an electrical engineer, working on
an embedded system like a chip inside a microwave
or a drone, you don't have a monitor. You just
have the circuit board. Right. So the hell of
a roll of hardware is the blinking LED. Like
a little heartbeat. Exactly. If you can write
code that makes a little light blink on and off
once per second, you have proven everything you
need to know. You've proven the power is on,
the chip is reading your code, the clock timing
is correct, and the physical output pin is properly
connected. It's the exact same sanity check,
just with photons instead of pixels. We see this
in every domain. In 3D graphics, text is actually
really hard to render. You need fonts, textures,
alignment, the huge pain. So in OpenGL or DirectX,
the sanity check is the hello triangle. Just
a triangle. Just a bright, colorful triangle.
If you see the triangle, your graphics driver
is working. I saw a note in our research about
the Excel programming language. They went a bit
further than a triangle. Oh, Excel. Yeah, they
show off a spinning 3D Earth. It's a bit of a
flex, basically saying 3D is so native to our
language that rendering a spinning globe is as
easy as printing text. And then there's CNC machines,
the big robotic drills. Their hello world is
terrifyingly physical. Oh, absolutely. If you
are programming a laser cutter or a CNC mill,
the hello world is getting the machine to carve
the words into a block of wood or plastic. Wow.
It is the code physically manifesting in the
real world. If you get that wrong, you don't
just get an error message on a screen. You break
a drill bit. Or cut a hole straight through your
table. Exactly. It's high stakes Hello World.
There is one group of programmers, though, who
apparently absolutely hate Hello World, the functional
programming crowd. Why do they have a beef with
a friendly greeting? This gets a little philosophical.
Functional languages, things like Haskell, ML,
or Lisp, treat programming like pure mathematics.
You put a number in, you get a number out. They
highly prioritize purity. And printing text isn't
pure? No, because it's a side effect. Define
that for us, for those who might not know. A
side effect is when a function changes the state
of the world outside itself, like modifying a
file, making a sound, or printing to a screen,
rather than just returning a value. For purists,
side effects are messy. I see. They are necessary
eventually, but they are the dirty part of coding.
So using a side effect as your very first lesson
is seen as teaching bad habits. So what did they
do instead of hello world? They usually calculate
a factorial, like five factorial is 120. It demonstrates
recursion in math without ever touching the messy
hardware. It's very academic. We don't want to
say hello. We just want to do math. That sums
up the functional community pretty perfectly.
They want to show you the beauty of the logic.
not the utility of the screen. So we've gone
from the B language hack in 1972 through the
two -year time to Hello World's struggle of Malbolge
all the way to blinking lights and CNC carving.
It's amazing how this one ritual has held on
for so long. It has held on because the fundamental
problem it solves hasn't changed. We still always
need to know, is this thing on? It's the bridge
between the abstraction of our code and the physical
reality of the machine. But there is a really
interesting suggestion in the research, specifically
from Mark Gosdiel and Elliot Soloway, that maybe
the era of Hello World is finally ending. This
is a fascinating, forward -looking idea. Their
argument is that computers themselves are changing.
For 50 years, the primary way we interacted with
computers was text. We typed, it typed back.
But look at how kids learn to code right now.
Like Scratch or Minecraft. Exactly. And Scratch.
You snap blocks together to make a cartoon cat
dance. In AI generation, you just ask for an
image. Text output isn't the primary mode of
communication anymore. So if I'm programming
a voice assistant, hello world might just be
a sound. Or if you're programming a haptic suit
for VR, it might be a pulse on your wrist, a
haptic handshake. That's a wild thought. As the
interface changes, the greeting changes. It forces
us to ask, what does it actually mean for a computer
to speak? If the future is brain -computer interfaces,
maybe Hello World is just a sensation of the
color blue directly stimulated into your visual
cortex. The Hello World of the future might just
be a feeling. It's highly possible. But whatever
form it takes, we will always need that first
moment of contact, that first confirmation that
we have successfully bridged the gap between
our mind and the machine. That is a great place
to leave it. Think about that for a while. Whether
it's a blinking light, a spinning triangle, or
just those two words on a black screen, the ritual
continues. It does indeed. If you've never done
it, maybe go look up a Python tutorial today.
Type the code. Make the machine say hello. It's
satisfying in a way that's really hard to describe
until you actually do it. Everyone should absolutely
do it at least once. Thanks for listening to
The Deep Dive. We'll catch you on the next one.