<h1>Never Wait</h1>
<blockquote>
<p><em>Preface:</em> This post is specif­i­cally about Pull Requests for <a href="https://github.com/Automattic/harper">Harper</a>.
Read the con­trib­u­tor guide­lines for a pro­ject be­fore open­ing a <span class="small-caps">PR</span>.</p>
</blockquote>
<p>I get it.
Open­ing a pull re­quest is an in­tim­i­dat­ing propo­si­tion.</p>
<p>It is non-triv­ial to put your blood, sweat, and (let’s be hon­est) tears into code and put that onto the in­ter­net for the world to see.
I re­mem­ber my ﬁrst pull-re­quest: it was­n’t pretty ei­ther.</p>
<p>But I want to high­light a cou­ple rea­sons why I want po­ten­tial con­trib­u­tors to open their pull re­quests as early as pos­si­ble.</p>
<h2>Drafts Reduce Duplicate Work</h2>
<p>When a con­trib­u­tor to a pro­ject is as­sess­ing the vi­a­bil­ity or use­ful­ness of some work they’re prepar­ing to do,
most look at ex­ist­ing Pull Requests ﬁrst.
Even if you’re still work­ing on the patch, it’s a great idea to open a<span class="push-double"></span> <span class="pull-double">“</span>draft” <span class="small-caps">PR</span> so no one starts work that could go to waste.</p>
<p>Further, if you have a draft open whose <span class="small-caps">CI</span> is fail­ing, a main­tainer may see it and ﬁx what­ever the prob­lem may be.
I ﬁnd my­self fre­quently brows­ing <a href="https://github.com/Automattic/harper/pulls">Harper’s Pull Requests</a> look­ing for fail­ing builds, since I’m of­ten the best equipped to ﬁnd the is­sue.</p>
<h2>It Helps With Debugging</h2>
<p>I try to make my­self avail­able to con­trib­u­tors in case they have any ques­tions re­gard­ing the ar­chi­tec­ture of Harper.
I’m also game to help de­bug their code, partly be­cause I am of the opin­ion that de­bug­ging is a skill which is best learned by ex­am­ple.</p>
<p>But it is hard for me to de­bug code if I don’t have it.
If a draft <span class="small-caps">PR</span> has been opened, I can usu­ally see the prob­lem with­out even cloning the code, since our <span class="small-caps">CI</span> is so com­pre­hen­sive.</p>
<h2>Conclusion</h2>
<p>So please don’t wait; open that PR.
I am thrilled each time I see a name I don’t rec­og­nize on a GitHub no­ti­ﬁ­ca­tion.</p>

Never Wait

<h1>What Is Randomness?</h1>
<img src="/images/numbers_on_a_screen.jpg" alt="Numbers on a screen">
<p>In case you were born yes­ter­day, let’s go over it.</p>
<p>Randomness is, at the most ba­sic level, some­thing that can­not be pre­dicted.
In com­puter sci­ence, when we talk about ran­dom­ness, we are usu­ally talk­ing about ran­dom num­bers and the tools we use to get them, ran­dom num­ber gen­er­a­tors (RNGs).</p>
<h2>Pseudorandomness</h2>
<p>We say an <span class="small-caps">RNG</span> is<span class="push-double"></span> <span class="pull-double">“</span>pseudorandom” when we have to give it a ﬁxed seed, and it gen­er­ates ran­dom num­bers based on that seed.
If we give it the same seed, we will get the same num­bers.
It is de­ter­min­is­tic.</p>
<p>I thought, for a very long time, that com­put­ers could only cre­ate pseudo­ran­dom num­bers.
The main rea­son I thought this, and why you might too, is be­cause util­i­ties like the Random class in&nbsp;.<span class="small-caps">NET</span> are pseudo­ran­dom and are seeded by some ar­bi­trary in­for­ma­tion, like the cur­rent time.</p>
<p>Computers aren’t use­ful if they aren’t de­ter­min­is­tic.
In a per­fect, en­closed sys­tem, it would be im­pos­si­ble for a com­puter to gen­er­ate truly ran­dom num­bers.</p>
<h2>True Randomness</h2>
<p>The phrase<span class="push-double"></span> <span class="pull-double">“</span>true ran­dom­ness” is used to de­scribe things that are im­pos­si­ble to pre­dict. Provably so. This is dif­fer­ent from chaotic sys­tems, which are pre­dictable un­der short spans of time.
True ran­dom­ness is im­pos­si­ble to pre­dict on all scales.</p>
<h2>The Everyday Method</h2>
<p>Allow me to in­tro­duce you to <a href="https://en.wikipedia.org/wiki/RDRAND"><span class="small-caps">RDRAND</span></a> and <a href="https://en.wikipedia.org/wiki/RDRAND#RDSEED"><span class="small-caps">RDSEED</span></a>, two <span class="small-caps">CPU</span> in­struc­tions orig­i­nally in­tro­duced by Intel, that al­low pro­grams ac­cess to truly ran­dom num­bers.
These in­struc­tions gather data from an on-chip en­tropy source to pro­vide ran­dom num­bers.</p>
<p>These in­struc­tions uti­lize ther­mal noise to pro­duce white noise, which is used to gen­er­ate said ran­dom num­bers.
The ad­van­tage of ther­mal noise is that it pro­duces ac­tu­ally ran­dom val­ues, as ex­plained here.
Its also fast, which means it can be used for every­day things, like gen­er­at­ing <span class="small-caps">SSL</span> or <span class="small-caps">TLS</span> keys and the like.</p>
<h3>Do It Yourself</h3>
<p>If you hap­pen to be on a Linux sys­tem, you can ac­tu­ally use these in­struc­tions your­self. Just run this com­mand:</p>
<pre><code class="hljs language-bash"><span class="hljs-built_in">dd</span> <span class="hljs-keyword">if</span>=/dev/random count=4 bs=1 status=none | <span class="hljs-built_in">od</span> -An --format=dI
</code></pre>
<p>This com­mand uses <code>dd</code> to gen­er­ate 4 ran­dom bytes.
Then it pipes those bytes into <code>od</code>&nbsp;, which will for­mat those 4 bytes into hu­man-read­able text as a signed 32-bit in­te­ger.</p>
<h2>The Nuclear Method</h2>
<img src="/images/nuclear_plant.jpg" alt="A Nuclear Plant">
<p>One of the big ad­vance­ments of the 20th Century was the cre­ation of a branch of re­search called quan­tum physics.
One of the things we learned was that on the scale of in­di­vid­ual par­ti­cles, it be­comes prov­ably im­pos­si­ble to pre­dict state.
Every time a mea­sure­ment is taken of a sub­atomic par­ti­cle, its state changes ran­domly.</p>
<p>One way we could sam­ple sub­atomic par­ti­cles is by plac­ing a Geiger counter next to a bit of ra­dioac­tive ore.
Be­cause whether an in­di­vid­ual atom will de­cay at any given mo­ment, we can know that the time be­tween ticks of the Geiger counter is ran­dom.</p>
<h2>The Cloudﬂare Method</h2>
<img src="/images/lava_lamp.jpg" alt="A Lava Lamp">
<p>Cloudﬂare uses some es­pe­cially in­ter­est­ing sources of en­tropy to seed its ran­dom num­ber gen­er­a­tors.
One way is via lava lamps.
In their lobby, they have a large ar­ray of lava lamps.
There is a cam­era run­ning a live feed of the lava lamps to their servers.
There are two main sources of ran­dom­ness.</p>
<p><strong>First</strong>, the lava lamps them­selves.
The move­ment of even a sin­gle lava lamp, if we for­get the sec­ond law of ther­mo­dy­nam­ics, is far too chaotic to pre­dict.
If we in­clude the sec­ond law of ther­mo­dy­nam­ics, it be­comes true ran­dom­ness.</p>
<p><strong>Second</strong>, the cam­era sen­sor’s noise.
Thanks to the pho­to­elec­tric ef­fect the noise that ap­pears on a cam­er­a’s sen­sor, how­ever un­no­tice­able, is truly ran­dom.</p>
<p>By com­bin­ing these two sources, you get a pool of truly ran­dom num­bers ~60 times a sec­ond.
If that does­n’t ﬁt your needs, you can use those num­bers to feed a cryp­to­graph­i­cally se­cure pseudo­ran­dom num­ber gen­er­a­tor (<span class="small-caps">CSPRNG</span>) to get as many as you want.</p>

We look at several interesting ways computers generate random numbers. It may fascinate you to know that some methods are not *truly* random, but only an approximate.

<p>We look at sev­eral in­ter­est­ing ways com­put­ers gen­er­ate ran­dom num­bers. It may fas­ci­nate you to know that some meth­ods are not <em>truly</em> ran­dom, but only an ap­prox­i­mate.</p>

3 Awesome Ways Computers Generate Randomness

It didn't work for me, and if you reading this, it probably won't work for you either.

Do Not Type your Notes

on_linkarzu

<h1>On Linkarzu’s YouTube</h1>
<p>I con­sider my­self an avid mem­ber of the Neovim com­mu­nity.
As a whole, they have a great pulse on what a good writ­ing ex­pe­ri­ence feels like.
Over time, this com­mu­nity has grown into a real force in the soft­ware en­gi­neer­ing ﬁeld.</p>
<p>Linkarzu has been a con­stant pres­ence in this ecosys­tem for a while, giv­ing a voice to the hid­den
main­tain­ers that make Neovim great.
I am hon­ored to be counted among the guests he has hosted on his chan­nel.</p>
<p>We talked at length about <a href="https://writewithharper.com">Harper</a>, open source main­te­nance, and the tool­ing we use in our de­vel­op­ment work­ﬂows.</p>
<iframe width="100%" height="400" src="https://www.youtube.com/embed/l9D7M1gIY8I?si=dXhZKospDwyb6zmU" title="YouTube video player" frameborder="0" allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share" referrerpolicy="strict-origin-when-cross-origin" allowfullscreen></iframe>

I was honored to be a guest on Linkarzu's YouTube series.

<p>I was hon­ored to be a guest on Linkarzu’s YouTube se­ries.</p>

Elijah Potter

On Linkarzu’s YouTube

Other Stuff

Never Wait

3 Awesome Ways Computers Generate Randomness

Do Not Type your Notes