8 ms·
Can an email go 500 miles in 2025?
https://archive.ph/h1AhH https://archive.ph/h1AhH
- robin_reala 1y agoIf you’re one of today’s lucky 10,000 and haven’t heard the original 500-mile email story, you can read it at https://web.mit.edu/jemorris/humor/500-miles https://web.mit.edu/jemorris/humor/500-miles. (discussed previously on HN 5 years ago – https://news.ycombinator.com/item?id=23775404 https://news.ycombinator.com/item?id=23775404 – and 10 years ago – https://news.ycombinator.com/item?id=9338708 https://news.ycombinator.com/item?id=9338708)
- hahahacorn 1y agoEven after reading the 2025 updated version, reading the original made me absolutely giddy at the end. I can only imagine the euphoria of reconciling the inputs of “the things I know to be true of computers and email” and “my emails won’t send further than 500 miles”. What a great story - thanks for posting the original.
- ericpauley 1y agoI have a tough time deciding a favorite between this story and “the ultimate in garbage collection”: https://devblogs.microsoft.com/oldnewthing/20180228-00/?p=98125 https://devblogs.microsoft.com/oldnewthing/20180228-00/?p=98...
- snowwrestler 1y agoDoes this system release all the memory it allocates? Yes, it releases it at about 200 meters per second.
- vghaisas 1y agoI collected a list of fun stories of this form a while ago! - Car allergic to vanilla ice cream: https://www.cs.cmu.edu/~wkw/humour/carproblems.txt https://www.cs.cmu.edu/~wkw/humour/carproblems.txt - Can't log in when standing up: https://www.reddit.com/r/talesfromtechsupport/comments/3v52pw/i_cant_log_in_when_i_stand_up/ https://www.reddit.com/r/talesfromtechsupport/comments/3v52p... - OpenOffice won't print on Tuesdays: https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161/comments/28 https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161... - The Wi-Fi only works when it's raining: https://predr.ag/blog/wifi-only-works-when-its-raining/ https://predr.ag/blog/wifi-only-works-when-its-raining/
- hinkley 1y ago“WiFi doesn’t work in the summer” is one of the first anecdotes I learned about WiFi when it was still brand new. You set up WiFi between two buildings in the winter, spring comes and the water in the leaves blocks the signal.
- madcaptenor 1y agoThis also happens with satellite TV.
- salviati 1y agoMonitor switches off when I sit down deserves to be on that list (even if it's hardware, not software): https://old.reddit.com/r/techsupport/comments/2rsivw/monitor_shuts_off_briefly_when_i_stand_up_from_my/ https://old.reddit.com/r/techsupport/comments/2rsivw/monitor...
- vidarh 1y agoIt's not quite in the same league as any of this, but when I was a child, we sent our Commodore 64 in for repairs several times because it started "writing" by itself. Gibberish would slowly appear as if someone was randomly hitting the keyboard. Each time it took several days before they repair centre got to it, and they then contacted us to tell us there was nothing wrong with the computer at all. After we picked it up, eventually, when it started happening again for the third or fourth time, we realised the problem: The "large" (a whopping 26") CRT TV we'd recently started placing it under when not in use caused it... A few days away from the TV to dishcharge it, and it was fine - hence why the repair technician didn't find anything.
- mtillman 1y ago"...even of a relatively impoverished department like statistics." Perfection.
- ableal 1y agoI got curious what Trey Harris (the original 500 mile story teller) was up to these days, but Google mostly finds me a football player born around that time (2002).
- jhalstead 1y agoPresumably this is the author given their UNC and SysAdmin background: https://www.linkedin.com/in/treyharris https://www.linkedin.com/in/treyharris I found it via a "trey harris sage.org" search on Google.
- lesser-shadow 1y agoFirst time I'm hearing about this actually, thank you.
- thenobsta 1y agoThanks for letting me be one of the lucky ones. Obligatory xkcd 10,000 lucky people explainer: https://xkcd.com/1053/ https://xkcd.com/1053/
- dgritsko 1y agoAnd if you're one of today's lucky 10,000 and haven't heard of the concept of "lucky 10,000", you can read the relevant XKCD here: https://xkcd.com/1053/ https://xkcd.com/1053/
- SoftTalker 1y ago9,999 remaining.
- kibwen 1y agoAnd if you're one of today's lucky 10,000 who haven't heard of XKCD: https://www.explainxkcd.com/wiki/index.php/xkcd https://www.explainxkcd.com/wiki/index.php/xkcd
- jeffhuys 1y ago> units 751 units, 62 prefixes You have: 10 miles You want: meters * 16093.44 / 6.2137119e-05 Huh. Never knew that was a thing!
- bqmjjx0kac 1y agoI always want to reach for `units`, but I'm perennially baffled by the output! What's up with the * and /?
- Arnavion 1y agoThe * value is the result of converting 10 miles to meters, as requested. The / value is the inverse of that in case you wanted that, ie 0.1 meters in miles. It's explained in `man 1 units`
- bqmjjx0kac 1y agoOh, I know it's explained in the man page. I read it every time and promptly forget because I can't internalize the choice of notation.
- jagged-chisel 1y ago* multiply / divide
- bqmjjx0kac 1y agoI am familiar.
- spacepotato 1y agoIf you find the output a bit hard to parse at times (as I do), you might want to try qalc instead, I use it all the time from the terminal to do conversions: $ qalc > 3 millilightseconds to miles 3 milliLightSeconds ≈ 558 mi + 1491 yd + 0.1692913386 ft I'm not sure if it has all the same units as `units` does, but it replaced my use of it entirely as it can do other useful operations as well
- jjice 1y agoThank you for linking this - I need to save this locally because I reference this all the time. This is one of my favorite internet stories - it's just a great arc!
- firefax 1y agoreminds me of the magic/more magic switch story
- jekwoooooe 1y agoEasily my favorite story on the internet
- redbell 1y agoThis was the highest-voted submission, posted two years ago: https://news.ycombinator.com/item?id=37576633 https://news.ycombinator.com/item?id=37576633
- strangescript 1y agoReading the title and knowing exactly what this is about kind of makes me feel old to be honest.
- JadeNB 1y ago> Reading the title and knowing exactly what this is about kind of makes me feel old to be honest. Let's go for experienced and ready to educate the young'uns.
- jraph 1y agoYou could have discovered that story yesterday :-)
- cs02rm0 1y agoIf it makes you feel better, I'm so old I read the title and 3/4 of the original story before I realised I'd read it before.
- r0uv3n 1y agoI think this is enough of a classic to be widely known even among younger people. I'm 23 (doing math msc) and I think all the CS people that I know would instantly recognize the 500 miles title. Though I do somewhat envy the possibility of having read the article close to publication and feel in some sense part of the history when it crops up again like this.
- cedws 1y agoIt’s a HN classic, any HN addict knows it.
- jancsika 1y agoIs there a library to re-introduce relevant delays into a CDN so that all users experience their own geographically-appropriate response times? I mean, I want reliability. But I also want Europeans to be able to taste that authentic latency they'd expect from a fledgling startup running out of a garage in San Jose.
- lesser-shadow 1y agoDon't get it
- voidUpdate 1y agoData can only go about 500 miles in 3ms, and in the original story, that's how long the system took to time out, and would fail to send the email
- justusthane 1y agoIt’s a test of an old probably apocryphal story about a university that couldn’t send an email more than 500 miles: https://web.mit.edu/jemorris/humor/500-miles https://web.mit.edu/jemorris/humor/500-miles
- vidarh 1y agoBoth the person who supposedly configured Sendmail, and the person who wrote the story, have defended the truthfulness of it on HN in the past.
- justusthane 1y agoGood to know! I do love the story.
- lesser-shadow 1y agoCommenting late on this but I seriously didn't know about the story beforehand.
- SV_BubbleTime 1y agoIt’s a nerd story about short timeouts. Effectively a what is the speed of light or electricity in copper and over infrastructure. It’s a joke that doesn’t make any sense because 3ms was clearly bullshit devised for example. Don’t think about it too hard, it doesn’t suddenly snap into anything meaningful.
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- renrutal 1y agoI clicked the story wondering if the speed of light has changed since the late 90s. Apparently not.
- SV_BubbleTime 1y agoIt’s still speed of light in a medium, which is not speed of light. Electricity over copper it is 2/3 iirc.
- deadbabe 1y agoHFT firms have entire infrastructure that runs very close to the speed of light, beating the competition that runs on antiquated copper.
- hhmc 1y agoThere's no competition that's running on copper -- even competitors without latency sensitivity with still be running over fibre because that's just the baseline infrastructure in datacentres, transatlantic etc. Of course, yes, the HFT firms will be using also the standard tricks of microwave towers, shortwave radio, weather balloon etc, to beat the fibre route.
- ta1243 1y agospeed of packets over copper I think is actually faster than fibre
- smohare 1y ago[dead]
- welder 1y agoI thought this was about consolidation of email providers so your email never leaves a single datacenter: "10 years ago we couldn't send an email 500 miles, but these days we can't send it 500 miles because it just routes internally." Too bad, I think that would have been more interesting to read.
- banannaise 1y agoThis is the first roadblock the author runs into - lots of universities ping at <2ms, likely because everyone's on the same datacenter.
- geocar 1y ago> There’s a lot to the story that’s obviously made up... Obviously? I think I've had this phone call myself a few times, although in my experience it was never from a statistician and they didn't give me as much data, but I'm pretty sure the story is mostly accurate. > I think this is nonsense... why would an invalid or incomplete sendmail configuration default to three milliseconds? This is a wonderful question, and perhaps much more interesting than anything else in the page, but first, let's reproduce the timing; My desktop, a 2017 Xeon E7-8880 (144 cores of 2.3ghz; 1tb ram) with a load of 2.26 at this moment: $ time sleep 0.001 real 0m0.004s user 0m0.001s sys 0m0.003s On my i9-10900k (3.7ghz) current load of 3,31: $ time sleep 0.001 real 0m0,002s user 0m0,000s sys 0m0,001s (In case you think I'm measuring exec; time /bin/echo returns 0's on both machine) Now as to why this is? Well in order to understand that, you need to understand how connect() actually works, and how to create a timeout for connect(). Those skilled in the art know you've got a number of choices on how to do it, but they all involve multiple steps because connect() does not take a timeout as an argument. Here's one way (not too different than what sendmail does/did): fcntl(f,F_SETFL,O_NONBLOCK); if(-1==connect(f,...)&&errno==EWOULDBLOCK){ fd_set a;FD_ZERO(&a);FD_SET(f,&a); if(!select(f+1,&a,&a,NULL,{.tv_sec=0,.tv_usec=0})) { close(f);return error; } } If you read this carefully, you only need to ask yourself how much time can pass between the top of connect() and the bottom of select(), and if you think it is zero like tedu does, you might probably have the same surprise: Computers are not abstract machines, but made out of matter and powered by energy and thus subject to the laws of physics, and so everything takes time. For others, the surprise might be that it's still 3msec over twenty years later, and I think that is a much more interesting subject to explore than whether the speed of light exists.
- lordnacho 1y agoI thought the 3ms was more or less what a low-granularity clock would give you. So, not the clock that gives you nanos, but the big standard one that is useful if you just somewhat care that some timer has run out. Perhaps you use it to count frames (120fps ~ 8.3ms) or check whether some calendar event has happened. A 333 Hz clock seems like something you might have on computers going back to those days, even if not for the CPU.
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- vidarh 1y ago> The poll timeout is 3ms, as specified by the lore. I think this is nonsense, why would an invalid or incomplete sendmail configuration default to three milliseconds? The answer is that per the original story, it was not defaulting to three milliseconds. It was defaulting to 0, and the 3ms was just how long it took the system to check for a response with a 0 timeout: > Some experimentation established that on this particular machine with its typical load, a zero timeout would abort a connect call in slightly over three milliseconds. This is a very different scenario, as it's not clear there should be a poll() there at all (or more likely select() given the age of the story) to match the original, but if there was, the select would have a timeout of 0, not 3ms, and would just happen to be unable to distinguish between 0 and up to 3ms.
- banannaise 1y agoYeah, the article is a good one overall, but the truthering is obnoxious, especially since it hinges on a basic misreading of the original story.
- CrazyStat 1y agoThe original story is also about the statistics department, not the university president. It would be nice to get such details right.
- xp84 1y agoI really wouldn't have predicted the extreme amount of centralization, and arguably unnecessary centralization, that we have today for things like university email and web servers. Even 20 years ago when I was in college, the servers I interacted with including email, were all in our school's /16. They did have software packages for LMS and stuff, but those were mostly deployed on-prem. Today the websites are hosted on third party cloud servers (my school's main website is some company that hosts your Wordpress or Drupal site so you don't have to) and the email by Microsoft or Google. Same for every school it seems. I guess the IT department that used to run all the infra is now probably just a few people in charge of ordering new laptops for faculty/staff when they break, and replacing Wi-Fi access points every 5 years.
- sombrero_john 1y agoYou answered your own question. IT staff is expensive, a SaaS subscription less-so.
- rrr_oh_man 1y agoYou, sir, obviously have not dealt with enterprise SaaS subscriptions
- rtkwe 1y agoSpam is another reason most places don't bother with selfhosting email now. Big providers like GMail aggressively filter unknown servers so if you attempt to host your own and don't setup everything perfectly (or even if you do and you trigger their filter ban threshold) all your email will silently fail to deliver or be blackholed to the Spam folder for the largest email providers and you might never find out or have a way to get them to reconsider.
- SchemaLoad 1y agoSomething I faced at multiple companies before Google and MS took over was that malware would get on your mail server and start blasting out spam. And then you'd find yourself on a bunch of blacklists thinking they made a mistake but it's because your server was actually spamming.
- ta1243 1y agoWe have a program which the company who developed lost the ability to rebuild the app for some reason. It has a 500ms timeout to load some settings from a server in the UK via TLS. If it goes more than that 500ms (or something, it's unclear the exact timeout cause) the app just vapourises. This is fine in the UK, TLS needs about* 3 times RTT to complete though, so an RTT above about 160ms and it's screwed. Almost all our users are in the UK, europe, mid-east or east coast USA, and in that 160ms RTT range. We ran into issues when a dozen people tried to use it in Australia, so the principal still happens with some badly written code.
- DmitryOlshansky 1y agoPatching the binary is an option, though it’s tricky I would attempt it anyway.
- ta1243 1y agoAlas an ios app, which is in the app store. It was a "nice feature" of an older unrelated system, we're going through a procurement to replace it, as patching a binary is fine for me, but not really a supportable solution at an enterprise level :D
- YesThatTom2 1y ago> there was a university president who couldn’t send an email more than 500 miles, and the wise sysadmin said that’s not possible, so the president said come to my office, and lo and behold, the emails stopped before going 500 miles. NO. NO NO NO. How can you get SO MANY facts wrong when the freaking story is googlable? Here's the original email: https://web.mit.edu/jemorris/humor/500-miles https://web.mit.edu/jemorris/humor/500-miles Here's the FAQ that covers the ambiguous parts: https://www.ibiblio.org/harris/500milemail-faq.html https://www.ibiblio.org/harris/500milemail-faq.html This annoys me because I know the original author and I remember when this happened (he told the story a few times). Let's recap: > there was a university president NO! It was the chairman of the statistics department. > who couldn’t send an email more than 500 miles, True. Being in the statistics department he had the tools to make actual maps. > and the wise sysadmin said that’s not possible, so the president said come to my office Kind of true. There was an office involved. > and lo and behold, the emails stopped before going 500 miles. True. > There’s a lot to the story that’s obviously made up, NO! Zero of this story was made up. ALL the people that were involved in the story are still alive. You can literally get them on the phone and talk to them. We're not debating whether or not Han Solo ever used a light saber. THIS SHIT REALLY HAPPENED. Sheesh.
- ddejohn 1y agoThe whole tone of TFA is super frustrating. The original story is funny, well written, and, well, a story meant to be told "over drinks at a conference". TFA misses all the humor and generally seems to be written by a very bitter person.
- EnPissant 1y agoI think the entire story was made up, but certainly the author admits much of it was made up. > 4. If you are not 100% sure of the details, then why are there so many details in the story? > Because with the details, the story looks much better. Do you really think that if I started each sentence with the words “I don’t remember exactly, but it seems to be ...”, then something would have changed? In the end, at the very beginning, I warned that some minor details were changed, and some were intentionally omitted - just to make the story better. > The second important point is the site where the story was first published. I sent this story to the SAGE (System Administrators Guild) mailing list in the "incredible challenges" section. These were just stories about the most incredible tasks that management sometimes puts to system administrators. And let's not forget the the post ends with: > I'm looking for work. If you need a SAGE Level IV with 10 years Perl, tool development, training, and architecture experience, please email me at trey@sage.org. I'm willing to relocate for the right opportunity. Which I think was the true purpose of the (to me) made up story.