Content-Type: text/shitpost

Subject: Another trivial utility: do-over
Path: you​!your-host​!ultron​!gormenghast​!qwerty​!fpuzhpx​!plovergw​!plover​!shitpost​!mjd
Date: 2018-06-29T20:52:35
Message-ID: <>
Content-Type: text/shitpost

I have been waffling for several days about whether to post this. Argument in favor:

I really like this command! A lot!

Argument against:

I don't understand why, since it doesn't actually do anything.

It's called do-over and it's just a glorified loop. You say something like

    do-over command args....

and it replies

    Hit <enter> to start

When you hit enter, it runs command args, and then it prompts again:

    Job completed in 12.3s
    Hit <enter> to re start

If someone else were showing me this, I would ask:

Why is this better than hitting the up-arrow and then enter?

or possibly

Why is this better than while read x; do command...; done?

I have no answer to these questions. But I have done a lot of both of those other things, and I like this better, although I don't know why.


    use Time::HiRes qw(time);

    print STDERR "Hit <enter> to start\n";
    while (1) {
          my $x = <STDIN>;
          last unless $x;
          print STDERR scalar(localtime()), "\n";
          my $start = time();
          print STDERR "running @ARGV\n";
          my $elapsed = time() - $start;
          printf STDERR "Job completed in %.1fs\n", $elapsed;
          print STDERR "Hit enter to restart\n"; 

Subject: Today I learned…
Path: you​!your-host​!wintermute​!hardees​!m5​!plovergw​!shitpost​!mjd
Date: 2018-06-29T16:55:22
Message-ID: <>
Content-Type: text/shitpost

I was looking at a map of West Virginia and I saw there is a town named New Vrindaban. “That's a surprising name for a town in West Virginia,” I said, so I looked it up. Aha, it was founded by ISKCON, now it all makes sense.

New Vrindaban has a web site.

Subject: A metric coincidence
Path: you​!your-host​!wintermute​!glados​!extro​!goatrectum​!plovergw​!shitpost​!mjd
Date: 2018-06-29T13:23:32
Message-ID: <>
Content-Type: text/shitpost

It is that case that $$\sqrt5\frac{\text{mile}}{\text{hour}} = \frac{\text{m}}{\text{s}}$$ almost exactly, so of course also $$5\frac{\text{mile}}{\text{hour}} = \sqrt5\frac{\text{m}}{\text{s}}.$$

I would find this more delightful if it hadn't just caused me so much confusion. I couldn't figure out whether I was supposed to multiply or divide because the number was the same both ways around. Still it might make a useful mnemonic, if I could remember which way around it was.

Subject: Today I learned…
Path: you​!your-host​!warthog​!goatrectum​!plovergw​!shitpost​!mjd
Date: 2018-06-25T14:38:29
Newsgroup: talk.mjd.ncube
Message-ID: <>
Content-Type: text/shitpost

There was a political party in Zimbabwe called “Movement for Democratic Change – Ncube”. Unfortunately it seems to have nothing to do with actual N-cubes; it is named for MDC founder Welshman Ncube, who also seems to have nothing to do with actual N-cubes.

Disappointing, but nothing compared to my childhood discovery that the biblical Book of Numbers had nothing to say about actual numbers.

Subject: Indecent math jargon
Path: you​!your-host​!wintermute​!wikipedia​!hardees​!m5​!plovergw​!shitpost​!mjd
Date: 2018-06-19T20:43:41
Newsgroup: talk.mjd.math-terminology-indecent
Message-ID: <>
Content-Type: text/shitpost

A couple of times I have witnessed discussions of what mathematical term is the most off-color or indecent-sounding. Of course someone always mentions the hairy ball theorem immediately and this is usually acclaimed the best (worst?).

But in my opinion the winner is “the class of forbidden minors”.

Subject: My least favorite mathematical term
Path: you​!your-host​!warthog​!goatrectum​!plovergw​!plovervax​!shitpost​!mjd
Date: 2018-06-19T20:31:55
Newsgroup: comp.lang.haskell.math-terminology-symplectic
Message-ID: <>
Content-Type: text/shitpost

“Symplectic”. What the hell does it mean? As far as I can tell, nothing.

Subject: A mathematical terminology failure
Path: you​!your-host​!walldrug​!epicac​!goatrectum​!plovergw​!ploverhub​!shitpost​!mjd
Date: 2018-06-19T20:28:33
Newsgroup: talk.mjd.math-terminology-failure
Message-ID: <>
Content-Type: text/shitpost

If you have a system of vectors, and you want a related system that spans the same space but is pairwise normal, you should obviously normalize the system.

No that's completely wrong. You can normalize them, but it won't help. If you want them to be normal, you have to orthogonalize them.

That sucks.

Subject: Crosswords people
Path: you​!your-host​!walldrug​!epicac​!qwerty​!fpuzhpx​!plovergw​!plovervax​!shitpost​!mjd
Date: 2018-06-19T20:21:56
Newsgroup: talk.mjd.linkedin-buddies
Message-ID: <>
Content-Type: text/shitpost

Today I got a LinkedIn invitation from someone (that I don't know) whose description reads as follows:

About US

Working at the crosswords people and transformative technologies, [our company] Delivers innovarive business solutions - powered by top talent - to help organizations reach their strategic and realize opportunities now and in future.

Except to redact the company name, I did not change a word of this.

I had to ask around to find out whether this was a parody account, posted in mockery of LinkedIn itself, because if so, I love it. But at this point I think it is sincere. I almost want to start my own parody account, but I don't think I could do it this well.

Subject: The dream of the Tsar's clock
Path: you​!your-host​!walldrug​!epicac​!thermostellar-bomb-20​!twirlip​!am​!plovergw​!shitpost​!mjd
Date: 2018-06-19T17:05:10
Message-ID: <>
Content-Type: text/shitpost

Last night I had a dream in which I was telling the following hilarious joke:

Once upon a time in Russia, the Tsar owned a magnificent handmade clock. It covered almost an entire wall, and was marvelously ornamented, with two accompanying decorations, resembling religious icons, to be hung on the wall flanking it.

There was a merchant who coveted the clock, and one day, unable to resist any longer, he hired some thieves to break into the Tsar's palace and steal the clock, which he then hung in his own home.

The very next day, who should happen by but the Tsar himself, with his retinue and bodyguards. Of course it would have been unforgivably rude to turn away that Tsar, so the merchant reluctantly invited him in.

The Tsar gazed at the clock on the wall. “That is a magnificent clock,” he said at last. Not knowing what else to say, the merchant agreed.

“I have one just like it,” said the Tsar.

That was the punch line.

Dreams. (Shrug.)

Subject: Shampoo
Path: you​!your-host​!ultron​!uunet​!asr33​!hardees​!brain-in-a-vat​!am​!plovergw​!plovervax​!shitpost​!mjd
Date: 2018-06-18T15:30:06
Message-ID: <>
Content-Type: text/shitpost

A small bottle of hotel shampoo,
labeled “Neutrogena® CLEAN normalizing shampoo”

I'm sorry I used this now that every one of my hairs is perpendicular to my scalp.

Subject: How I became MJD
Path: you​!your-host​!walldrug​!kremvax​!hal9000​!plovergw​!plovervax​!shitpost​!mjd
Date: 2018-06-17T15:27:52
Newsgroup: alt.mjd.mjd
Message-ID: <>
Content-Type: text/shitpost

I was not intending to be known as “MJD”. It happened by accident.

When I got my first full-time job, as a Unix system administrator, my boss, Mark Foster, asked me what username I would like. He had mark, so that was unavailable.

At college I had had entropy, but I wasn't sure that would be appropriate.

(The first time I chose my own username I was unprepared for the question. I sat there staring at the screen for two minutes, unable to think of anything good, and finally, wanting only to move on, entered puswad. Some months later that admin of that lab asked if I would be willing to change my username. He had to include it on reports that he gave to his boss about the lab, and felt embarrassed every time he saw it. Hence entropy.)

Mark assured me that entropy would not be a suitable email address for a staff person. Thinking of the ilustrious history of dmr and rms and so forth, I suggested mjd and the die was cast.

What I wasn't expecting was that people would start calling me that. For a long time I resisted it. “That is not my name,” I would say. “It's just my email address.” On chat systems I would always choose something else because I didn't want to encourage the trend of people calling me “MJD” to my face.

But I didn't want to change it, and eventually, I gave up. Now, many years later, it seems very natural for people to call me “MJD” and I am sometimes startled when they don't.

My first Unix username was dominusm, assigned by some other person or perhaps an automatic process. My colleagues David Hiebeler and George Kyriazis were similarly assigned hiebeled and kyriazig. This infuriated me. Eight characters were available, so why not hiebeler and kyriazis? Why mangle people's names for a foolish consistency? I resolved that if I were ever in charge of assigning usernames, I would do a better jobs, and eventually, I did.

One day I was trying to type telnet but my left hand was on the wrong position and I typed yrlnry by mistake. When Dada lightning strikes like that, I take it seriously. On IRC I was yrlnry for many years. The only thing that prevented me from using it more widely is that people seem unsure how to pronounce it. (/yuril-nury/) Another benefit: since it's hard to prounounce, people wouldn't try to call me that when they met me.

But I usually prefer to use my real name. I don't (usually) want to be pseudonymous, and I think “Mark Dominus” is a great name. I often find nicknames silly, pompous, or juvenile, and I often find myself feeling embarrassed for people who use them. It is tempting to insert some especially painful examples here, but one of the rules of this blog is: no mockery of any specific and identifiable private persons. But maybe you can imagine me cringing when I think of someone who goes around calling himself “Elrond”.

On Math Stackexchange I originally used “Mark Dominus” but then I found to my distaste that Google searches for my name turned up my SE contributions and nothing else, so I changed it to “MJD”. The SE thing reminds me of something related. There is a certain class of SE user that chooses as their avatar a picture of David Hilbert or Georg Cantor, which I would never dare do. It seems conceited and vainglorious. I make plenty of dumb mistakes and I do not want to make them right above a picture of Niels Henrik Abel. I chose my own avatar specifically to get as far as possible from that:

A potato
A screenshot of a Math.SE post,
with my name and potato avatar at the lower-right corner

I think this is hilarious.