[HN Gopher] Can an email go 500 miles in 2025?
       ___________________________________________________________________
        
       Can an email go 500 miles in 2025?
        
       Author : zdw
       Score  : 242 points
       Date   : 2025-07-04 16:49 UTC (4 days ago)
        
 (HTM) web link (flak.tedunangst.com)
 (TXT) w3m dump (flak.tedunangst.com)
        
       | robin_reala wrote:
       | If 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.
       | 
       | (discussed previously on HN 5 years ago -
       | https://news.ycombinator.com/item?id=23775404 - and 10 years ago
       | - https://news.ycombinator.com/item?id=9338708)
        
         | hahahacorn wrote:
         | Even 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 wrote:
           | I have a tough time deciding a favorite between this story
           | and "the ultimate in garbage collection": https://devblogs.mi
           | crosoft.com/oldnewthing/20180228-00/?p=98...
        
             | snowwrestler wrote:
             | Does this system release all the memory it allocates?
             | 
             | Yes, it releases it at about 200 meters per second.
        
           | vghaisas wrote:
           | I 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
           | 
           | - Can't log in when standing up: https://www.reddit.com/r/tal
           | esfromtechsupport/comments/3v52p...
           | 
           | - OpenOffice won't print on Tuesdays: 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/
        
             | hinkley wrote:
             | "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 wrote:
               | This also happens with satellite TV.
        
             | salviati wrote:
             | Monitor switches off when I sit down deserves to be on that
             | list (even if it's hardware, not software): https://old.red
             | dit.com/r/techsupport/comments/2rsivw/monitor...
        
             | vidarh wrote:
             | It'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.
        
             | llimos wrote:
             | - A Story About 'Magic'
             | http://www.catb.org/jargon/html/magic-story.html
        
             | abejfehr wrote:
             | This site has a collection of them: https://500mile.email/
        
             | markstos wrote:
             | I once had a desktop computer that had great uptime, but
             | started to consistently crash when I got up and left the
             | room to get a drink of water.
             | 
             | Turns out it was old building with loose floorboards. The
             | vibrational force of standing up was enough to short out a
             | failing power supply. As long as I sat my desk, it was
             | fine.
             | 
             | But I had a co-worker who had a worse problem with getting
             | up to get a drink of water. Once while she was kitchen, an
             | eight foot steel lighting ballast came loose from the
             | ceiling and felt right onto her chair.That what-if memory
             | still haunts me.
        
               | lloeki wrote:
               | > The vibrational force of standing up was enough to
               | short out a failing power supply
               | 
               | Or, was it?
               | 
               | https://superuser.com/questions/1406140/monitor-screen-
               | that-...
               | 
               | (not disclaiming that it wasn't, but that "chair piston
               | causes EM surge" had me driven crazy for the longest time
               | til I was able to pinpoint the cause)
        
               | duped wrote:
               | I saw this in an office while working on an embedded
               | project where our dev boards had no EM shielding.
               | 
               | Standing up from the chair was enough to cause it to
               | crash.
        
             | anton-c wrote:
             | I wonder if the feeling is excitement or horror when you
             | encounter one of these weird problems that seems like it
             | has to be the user.
             | 
             | Not computer related really, but I'm reminded of when my
             | Mom was helping set up macs in the lab at my middle school.
             | I, a 4th grader, tagged along and hung out in the other lab
             | across the hall. I got very incredulous looks when i
             | claimed that there was a lizard in there. It was the
             | Midwest over summer break! I was obviously a kid seeing
             | things. There's no lizards here.
             | 
             | Then I produced it, caught under a bin. It was a brown
             | anole that had come back in a plant sent from Florida. I
             | wasn't crazy _that_ day.
        
               | jwrallie wrote:
               | Since you mentioned your mom, mine is not as tech savvy.
               | At one point she needed a computer to type something and
               | print it, a simple use case so I came up with this idea
               | of setting up a computer that would give me no tech
               | support trouble, since I was living in another state. I
               | installed CentOS, libre office and made sure the printer
               | was supported.
               | 
               | I told my mom to keep the system up to date and set up an
               | ssh connection for remote access just in case.
               | 
               | A few months go by and one day I receive a phone call
               | that she cannot find the system updater shortcut anymore.
               | I started to think how I could get Gnome to load over
               | ssh, I was sure she moved the icon accidentally or
               | something but decided to google it just in case.
               | 
               | Lo and behold and there is a bug report that due to some
               | bug in package management dependency resolution the
               | graphic software updater GUI could remove... itself... if
               | the user performed a routine system update. It seemed to
               | even affect RHEL at the time if I'm not mistaken.
               | 
               | A yum install command away over ssh and it was solved but
               | that was the day I realized that no matter how stable a
               | distro is famed to be or how much support it has from a
               | company, there was still lots of work to be done until
               | Linux could be seen as friendly enough for the end user.
        
             | d--b wrote:
             | I had one of these myself. WiFi wouldn't work when my wife
             | was using her laptop in bed. As soon as she gave it to me,
             | it started working again. She thought it was the magic
             | touch of the engineer, but it turned out that when she was
             | in bed, she pulled her knees up and set the computer on her
             | lap, while I would lay down completely and let the computer
             | rest on my chest. Her knees blocked the WiFi signal enough
             | to be quite noticeable.
        
             | Tarsul wrote:
             | there's also the story that wiggling the mouse in Win95
             | when installing something really _does_ make it go faster. 
             | https://retrocomputing.stackexchange.com/questions/11533/wh
             | y...
        
               | rft wrote:
               | There also is the (somewhat) famous caps lock gamble in
               | XCOM 2 [1].
               | 
               | Quote: "Hitting the key, through a rube-goldberg-esque
               | series of events, forces all outstanding load requests to
               | be filled immediately in a single frame. This causes a
               | massive hitch, and potentially could crash the game. If
               | you don't care about those adverse effects the
               | synchronous load is faster."
               | 
               | [1] https://www.eurogamer.net/a-single-button-press-
               | skips-loadin...
        
             | b3lvedere wrote:
             | I've seen some weird technical glitches in my career. One
             | that i will always remember is that a customer was very
             | happy with his new big computer, but could not work for
             | multiple hours on it, because his office would get colder
             | and colder when he kept using it. After some mailing and
             | talking over the phone i suggested a visit to his office
             | where i quickly found the cause of the problem: The big
             | computer fan was aimed directly at the thermostat knob of
             | the radiator, so it assumed the entire office was well
             | heated and closed.
        
             | rich_sasha wrote:
             | At one point, my scanner only worked when my daughter was
             | awake - never when she was asleep (nighttime or napping).
        
             | lilyball wrote:
             | Most of these are good, but "can't log in while standing
             | up" is just too implausible. I can't possibly be led to
             | believe that every single one of a whole group of
             | technically-literate touch typers failed to notice that
             | keys were swapped.
        
             | redbell wrote:
             | As seen on HN:
             | 
             |  _Car allergic to vanilla ice cream_ :
             | https://news.ycombinator.com/item?id=37584399 and
             | https://news.ycombinator.com/item?id=13347852
             | 
             |  _The Wi-Fi only works when it 's raining_:
             | https://news.ycombinator.com/item?id=39896371
        
           | mtillman wrote:
           | "...even of a relatively impoverished department like
           | statistics."
           | 
           | Perfection.
        
         | ableal wrote:
         | I 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 wrote:
           | Presumably this is the author given their UNC and SysAdmin
           | background: https://www.linkedin.com/in/treyharris
           | 
           | I found it via a "trey harris sage.org" search on Google.
        
         | lesser-shadow wrote:
         | First time I'm hearing about this actually, thank you.
        
         | thenobsta wrote:
         | Thanks for letting me be one of the lucky ones.
         | 
         | Obligatory xkcd 10,000 lucky people explainer:
         | https://xkcd.com/1053/
        
         | dgritsko wrote:
         | And 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/
        
           | SoftTalker wrote:
           | 9,999 remaining.
        
           | kibwen wrote:
           | And if you're one of today's lucky 10,000 who haven't heard
           | of XKCD: https://www.explainxkcd.com/wiki/index.php/xkcd
        
         | jeffhuys wrote:
         | > 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 wrote:
           | I always want to reach for `units`, but I'm perennially
           | baffled by the output! What's up with the * and /?
        
             | Arnavion wrote:
             | The * 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 wrote:
               | Oh, 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 wrote:
               | * multiply
               | 
               | / divide
        
               | bqmjjx0kac wrote:
               | I am familiar.
        
               | spacepotato wrote:
               | If 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
        
             | barnas2 wrote:
             | the * is denoting the conversion from your first unit to
             | your second, the / denotes the other way.
             | 
             | You have: 1 miles You want: feet * 5280 / 0.00018939394
             | 
             | In the above example, 1 mile is 5280 feet, and 1 foot is
             | 0.00018939394 miles
             | 
             | If I do 2 miles to feet, the values are doubled (or halved
             | for the reverse conversion)
             | 
             | You have: 2 miles You want: feet * 10560 / 9.469697e-05
        
             | Symbiote wrote:
             | I usually call it non-interactively:                 $
             | units 1500DKK USD           * 236.76653           /
             | 0.00422357
             | 
             | in which case it's always the first line I want.
             | 
             | (The second line is telling me 1USD is 0.00422357 of
             | 1500DKK.)
             | 
             | Note if you use the currency conversions,
             | systemctl enable units-currency-update.timer
             | 
             | is needed to keep them up-to-date.
        
           | bspammer wrote:
           | It's one of my most used utilities, as someone who can't help
           | but nerd-snipe myself on the regular. Example questions that
           | I've used it for, just in the last week:
           | 
           | If I work 42 hours/week, how many minutes is that per year?
           | 
           | I've downloaded 4.91GB in the last minute, what's that in
           | Mbps? How long will it take to download a 76GB game?
           | 
           | This AWS feature costs $0.045/hour, how much is that per
           | month?
           | 
           | This guy I read about traveled 58,000km in 27 years, what's
           | his average speed in m/s?
           | 
           | How much would a 10cm sphere of gold be worth in GBP?
           | 
           | If a 36 inch pipeline can deliver 25580 acre-feet of water in
           | a year, how fast is the water flowing in m/s?
        
             | jmoggr wrote:
             | > How much would a 10cm sphere of gold be worth in GBP?
             | 
             | Is there some trick to this? Or do you have to input it
             | like:
             | 
             | You have: 4/3 _pi_ (10 cm)^3 _19320 kg /m^3_45000 GBP/kg
             | 
             | (What ChatGPT gave me)
        
               | bspammer wrote:
               | units has (I assume room temp/pressure) densities for all
               | elements, as well as some precious metal prices and
               | currency exchange rates (you need to run the units_cur
               | program regularly to update the database for these). It
               | also has tab completion to make discovering these a bit
               | easier.
               | 
               | The invocation is
               | 
               | You have: goldprice * golddensity * spherevol(10cm/2)
               | 
               | You want: GBP
        
               | jmoggr wrote:
               | Neat! Thank you!
        
               | thedrexster wrote:
               | TIL -- thank you, brother!
        
               | sneak wrote:
               | You can just save a step and ask ChatGPT the answer. It
               | can google the current spot price of gold.
        
               | lazide wrote:
               | Sure, but then I need to do all the math to verify the
               | answer it gives me isn't gibberish anyway.
        
         | jjice wrote:
         | Thank 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 wrote:
         | reminds me of the magic/more magic switch story
        
         | jekwoooooe wrote:
         | Easily my favorite story on the internet
        
         | redbell wrote:
         | This was the highest-voted submission, posted two years ago:
         | https://news.ycombinator.com/item?id=37576633
        
       | strangescript wrote:
       | Reading the title and knowing exactly what this is about kind of
       | makes me feel old to be honest.
        
         | JadeNB wrote:
         | > 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 wrote:
         | You could have discovered that story yesterday :-)
        
         | cs02rm0 wrote:
         | If 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 wrote:
         | I 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.
        
       | jancsika wrote:
       | Is 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 wrote:
       | Don't get it
        
         | voidUpdate wrote:
         | Data 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 wrote:
         | It'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
        
           | vidarh wrote:
           | Both 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 wrote:
             | Good to know! I do love the story.
        
         | SV_BubbleTime wrote:
         | It'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.
        
           | vidarh wrote:
           | Why do you think it's "clearly bullshit"?
           | 
           | connect() will take time. Either you then fail on reiceiving
           | EINPROGRESS, or you attempt a select() with 0 for the
           | timeout, which will also take time. That that time could add
           | up to 3ms on a mid-90's system also used for other things
           | seems entirely plausible to me.
        
       | renrutal wrote:
       | I clicked the story wondering if the speed of light has changed
       | since the late 90s.
       | 
       | Apparently not.
        
         | SV_BubbleTime wrote:
         | It's still speed of light in a medium, which is not speed of
         | light. Electricity over copper it is 2/3 iirc.
        
           | deadbabe wrote:
           | HFT firms have entire infrastructure that runs very close to
           | the speed of light, beating the competition that runs on
           | antiquated copper.
        
             | hhmc wrote:
             | There'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.
        
               | deadbabe wrote:
               | There's always competition running on copper, shitty
               | little traders that think they can beat the big firms.
        
               | hhmc wrote:
               | I don't think the switches connecting to any real
               | exchanges support this
        
           | ta1243 wrote:
           | speed of packets over copper I think is actually faster than
           | fibre
        
             | layer8 wrote:
             | It seems to depend on the cable type: https://en.wikipedia.
             | org/wiki/Velocity_factor#Typical_veloci...
        
           | connicpu wrote:
           | ~200,000km/s is the speed of light in fiber optics.
           | Electromagnetic propagation in copper is more like 99% c.
        
             | layer8 wrote:
             | The insulating material significantly decreases the
             | propagation speed: https://en.wikipedia.org/wiki/Velocity_f
             | actor#Typical_veloci...
        
       | welder wrote:
       | I 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 wrote:
         | This is the first roadblock the author runs into - lots of
         | universities ping at <2ms, likely because everyone's on the
         | same datacenter.
        
       | geocar wrote:
       | > 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 wrote:
         | I 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.
        
         | MadnessASAP wrote:
         | > 144 cores of 2.3ghz; 1tb ram
         | 
         | I can't help but feel that's somewhat excessive for a desktop.
         | Have you considered closing a few browser tabs?
        
           | geocar wrote:
           | > I can't help but feel that's somewhat excessive for a
           | desktop.
           | 
           | I got it on ebay for EUR2k. You can't _not_ expect me to use
           | it as a desktop.
           | 
           | > Have you considered closing a few browser tabs?
           | 
           | No? I mean actually no: I made a brotab+wofi script that
           | allows me to search tabs, and I find it a lot more convenient
           | than bookmarks.
           | 
           | Here's the relevant bits:                   brotab_filter='{
           | split($1,A,".");          t=$2;          gsub(/&/,
           | "\\&amp;",t); gsub(/</,  "\\&lt;",t); gsub(/>/,  "\\&gt;",t);
           | print "<span size=\"xx-small\">"A[1]"."A[2]"</span><span
           | size=\"xx-small\">."A[3]"</span> <span
           | weight=\"bold\">Firefox</span> <span>"t"</span>"         }';
           | ( # more stuff is in here         brotab list | awk -F" "
           | "$brotab_filter" ) | \         wofi -m --insensitive --show
           | dmenu --prompt='Focus a window' | sed -e 's/<[^>]*>//g' | {
           | read -r id name || exit 1          case "$id" in
           | exec) exec "$name" ;;          [0-9]*)   swaymsg
           | "[con_id=$id]" focus ;;          [a-z]\.*)           brotab
           | activate "$id"; sleep 0.2;           swaymsg
           | "[title=\"${name#Firefox }\"]" focus           ;;
           | esac         }
           | 
           | Works fine on 19,294 tabs at the moment...
        
             | lazide wrote:
             | I think I love you.
        
         | chimeracoder wrote:
         | > 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.
         | 
         | Yeah, the original retelling even states up-front:
         | 
         | > The story is slightly altered in order to protect the guilty,
         | elide over irrelevant and boring details, and generally make
         | the whole thing more entertaining.
         | 
         | It's pretty common to alter minor details of stories in order
         | to make them easier to follow, not to mention that the entire
         | account is also written several years after it happened, when
         | details are presumably less likely to be completely accurate.
         | Obviously the dialogue is reconstructive for narrative ease; no
         | reader would look at that and assume it's intended to be a
         | verbatim transcript.
         | 
         | Unless the author here can cite specific things that make it
         | truly impossible for anything of that shape to have occurred,
         | I'm not seeing anything that justifies the conclusion "there's
         | a lot to the story that's obviously made up".
        
         | throw310822 wrote:
         | Never got this, honestly.
         | 
         | Well, first light does 500 miles in 3ms, but the connect signal
         | needs to come back, right? So it should be 250 miles, at most?
         | But this is just a detail.
         | 
         | More importantly, because it seems to assume that all other
         | operations besides the signal actually reaching the destination
         | are instantaneous. As you point out yourself, computers are not
         | abstract machines, so the actual response time between the
         | signal being received by the destination (even assuming it's
         | just one straight line with zero electronics in between) and
         | the destination replying is not zero. I imagine there can be a
         | large variation between physical installations and different
         | types of hardware, so much as to make it very hard to detect a
         | clear 500 miles boundary.
         | 
         | Or am I missing something?
        
           | ndiddy wrote:
           | The author wrote an FAQ several years after the original
           | story that answers most of your questions.
           | https://www.ibiblio.org/harris/500milemail-faq.html
        
             | throw310822 wrote:
             | Yes I think I had read those FAQ at some point, they're
             | terribly handwavy though.
             | 
             | "Should have been 6ms instead of 3 for the ACK to come
             | back? Yes, sorry, it was too boring to add"; "Should it be
             | much more and variable because of the routers in between?
             | Yes sure, I probably pinged them and added up the delays";
             | "Shouldn't plenty of deliveries have failed for
             | destinations much closer than 500 miles? Yes sure, but that
             | must have been the limit..." Etc.
        
               | lilyball wrote:
               | The "destinations much closer than 500 miles" was
               | explicitly handled in the story, I don't know why that
               | was even in the FAQ except that the asker failed reading
               | comprehension.
               | 
               | > _" There are a number of destinations within that
               | radius that we can't reach, either, or reach
               | sporadically, but we can never email farther than this
               | radius."_
        
       | vidarh wrote:
       | > 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 wrote:
         | Yeah, 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 wrote:
           | The original story is also about the statistics department,
           | not the university president. It would be nice to get such
           | details right.
        
       | xp84 wrote:
       | I 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 wrote:
         | You answered your own question. IT staff is expensive, a SaaS
         | subscription less-so.
        
           | rrr_oh_man wrote:
           | You, sir, obviously have not dealt with enterprise SaaS
           | subscriptions
        
         | rtkwe wrote:
         | Spam 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.
        
         | anonymfus wrote:
         | You totally could make that prediction just by thinking about a
         | number of schools in the world, a number of /16s in ipv4 and a
         | rate of ipv6 adoption.
         | 
         | Typically that "IT department" was just a few CS teachers, who
         | assigned some slacking students creating a webpage as a
         | homework, and replacing a bad memory in a server computer as a
         | lab work, and then gave up when that become impossible.
        
       | ta1243 wrote:
       | We 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.
        
       | YesThatTom2 wrote:
       | > 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
       | 
       | Here's the FAQ that covers the ambiguous parts:
       | 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.
        
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