6 ms·

Let me see if I'm the first one to link to that classic story in the same series, "I cannot send email further than 500 miles" http://www.ibiblio.org/harris/50

Let me see if I'm the first one to link to that classic story in the same series, "I cannot send email further than 500 miles" http://www.ibiblio.org/harris/500milemail.html http://www.ibiblio.org/harris/500milemail.html Or the Magic/More Magic switch http://www.catb.org/jargon/html/magic-story.html http://www.catb.org/jargon/html/magic-story.html It's fun when physical reality meets the abstract models that we have built in our heads of these machines.

tombert 3y ago
The 500 mile email story is one of my favorite reminders that, fundamentally, we're still governed by the laws of physics. It's funny, but it's also a reminder that, while networks might be very fast, the latency is still going to be governed by the speed of light.
- ck2 3y ago
  Well laws of physics is what gave us radio in the first place. Some of my favorite video documentaries are on how it was theorized and then slowly developed over years and decades until they finally got to spark-gap transmitters. https://en.wikipedia.org/wiki/Timeline_of_radio https://en.wikipedia.org/wiki/Timeline_of_radio But just imagine listening to spark-gap morse code radio broadcasts for years as amateur and then suddenly someone does a broadcast test of actual voice (violin!) That must have been incredible to hear wirelessly. 24 December 1906 Reginald Fessenden, that was the leap that eventually gave us wifi https://en.wikipedia.org/wiki/Reginald_Fessenden https://en.wikipedia.org/wiki/Reginald_Fessenden
- ortusdux 3y ago
  If we are doing classic stories - Grace Hooper and the Nanosecond of wire https://www.youtube.com/watch?v=9eyFDBPk4Yw https://www.youtube.com/watch?v=9eyFDBPk4Yw https://americanhistory.si.edu/collections/nmah_692464 https://americanhistory.si.edu/collections/nmah_692464
- hughesjj 3y ago
  I actually like thinking about the exchange of physical information as a network propagation delay, and entanglement/coherence as a distributed consensus algorithm. They're kinda samey from a conceptual point of view (in my amateur opinion)
amelius 3y ago
I came here to see if someone posted that.
tiltowait 3y ago
I forgot all about the 500 miles story. My favorite line: > If the problem had had to do with the geography of the human recipient and not his mail server, I think I would have broken down in tears.
lamontcg 3y ago
and previously discussed: https://news.ycombinator.com/item?id=9338708 https://news.ycombinator.com/item?id=9338708
asadhaider 3y ago
First thing I thought of too. Anyone know if there a list of more articles similar to these three?
- barryrandall 3y ago
  DNS responses sent over UDP are often truncated if the response is too large. This manifests itself as "machine unreachable if name > x characters" sort of errors when you have really long FQDNs.
- Tomte 3y ago
  My wife has complained that open office will never print on Tuesdays!? https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161/comments/28 https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161...
- fabatka 3y ago
  I remember one (might have been a hn-er's comment, dunno) about the computer restarting when the toilet was flushed. Turns out it was due to voltage drop when a compressor turned on to refill the reservoir of the toilet.
  - stavros 3y ago
    It was: https://news.ycombinator.com/item?id=39898272 https://news.ycombinator.com/item?id=39898272
  - saalweachter 3y ago
    That's why in rural locales with spotty power it pays to have a UPS on any electronics -- you might not benefit much from 15-30 minutes of extra power in a day long blackout, but it keeps everything happy when the voltage fluctuates.
- cyberax 3y ago
  My personal example: VoIP phones stopping after the Asterisk server was up for 3 days. Reason: the server had IPv6 turned on, and it steadily accumulated privacy IPv6 addresses. These addresses were all sent in a packet describing the supported media endpoints, using UDP. And yep, eventually it overflowed the MTU and the phones couldn't handle the fragment reassembly.
sebtron 3y ago
Or the "Car allergic to vanilla ice cream" story [1]. [1] https://news.ycombinator.com/item?id=37584399 https://news.ycombinator.com/item?id=37584399
duxup 3y ago
I had a customer who used a line of sight system for extending their network across part of a city. I had a shortcut on my desktop with the weather for that town ready when they would inevitably call and blame our unrelated equipment for some problem.
- scbrg 3y ago
  I worked at a small, local ISP in the 90:ies that had a point to point link across the river, handling the dial up traffic from the telecom company we partnered with. Every few days, always at roughly the same time, all incoming dial up traffic would drop. A minute later, the customers could reconnect. It took a while before we realized that one of the huge passenger ferries that docked a short distance upstream was the cause. When it arrived and departed, its chimneys and possibly bridge and highest deck blocked LOS across the river.
- dmurray 3y ago
  I used to work in high-frequency trading. I had several tabs permanently open to the live weather radar feed for regions where we had microwave towers: the NE USA, the South of England, the Alps...
  - seabass-labrax 3y ago
    I'm curious to know where your towers were. Do you know if they still exist? Were your microwave antennae co-located on other operators' towers (e.g. those for VHF radio), or did your company have towers all to itself?
    - dmurray 3y ago
      Without going into anything confidential - we had some of our own hardware, but generally rented capacity from firms like [0]. Some towers were custom built for HFT, some were shared with other types of users. A famous blog post investigating some of the towers as an outsider, at [1], will be of interest to you. If you want to guess where they are, get a globe, find the datacentres where electronic exchanges operate (it's not a secret: Chicago, New Jersey, London, Tokyo, Frankfurt, Zurich...) and draw the straightest possible lines between pairs of them. Microwaves don't cross the ocean. [0] https://www.mckay-brothers.com/ https://www.mckay-brothers.com/ [1] https://sniperinmahwah.wordpress.com/2014/09/25/hft-in-my-backyard-ii/ https://sniperinmahwah.wordpress.com/2014/09/25/hft-in-my-ba...
FergusArgyll 3y ago
Boy did that [0] send me down a long rabbit hole [0] magic-story
vikingerik 3y ago
My recent version: I was playing a pinball game in an arcade. One particular ramp shot was registering earlier in the day and then stopped working. Eventually I realized that the sensor is an optical beam, and the receiver happened to be in direct sunlight coming in through a window! So it was continuously receiving infrared and would never report the beam being blocked by a pinball. Sure enough, it started working again once the sun angle changed by a few more degrees.
- lupusreal 3y ago
  You missed an opportunity to cheat the machine by waving your hand between it and the sun. ;)
  - vikingerik 3y ago
    Heh, but not exactly. If I blocked the sun, the receiver still would have been picking up the real beam. I would have had to block the sun _and_ make the shot with a pinball at the same instant... which is just playing the game normally with extra steps.
- yencabulator 3y ago
  I have an optical smoke detector that will give (very loud) false alarms if a sun beam can bounce off a windowsill onto it. It works great if the curtain is closed. Debugging that took a few early sunrises.
freedomben 3y ago
Oh man, this is one of my favorite lines of all time: > "Anyway, I asked one of the geostatisticians to look into it--" > "Geostatisticians..." > "--yes, and she's produced a map showing the radius within which we can send email to be slightly more than 500 miles. 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." I adore when experts use their expertise to analyze real-world things like this and provide ridiculously thorough explanations :-D
- fsckboy 3y ago
  it's a useful analysis. Nobody thought of router hops, but this pattern is pretty much what you'd expect, so it was a very good hint.
- neilv 3y ago
  My favorite story kinda of this nature, of an expert as alien intelligence, was Feynmann's calculations about computer architecture of the Connection Machine: https://longnow.org/essays/richard-feynman-connection-machine/ https://longnow.org/essays/richard-feynman-connection-machin... It's a few paragraphs, maybe too much to quote, but the bulk of it starts with: > By the end of that summer of 1983, Richard had completed his analysis of the behavior of the router, and much to our surprise and amusement, he presented his answer in the form of a set of partial differential equations. To a physicist this may seem natural, but to a computer designer, treating a set of boolean circuits as a continuous, differentiable system is a bit strange. [...] Our discrete analysis said we needed seven buffers per chip; Feynman's equations suggested that we only needed five. We decided to play it safe and ignore Feynman. Guess who was right. The whole essay is worth reading, if you haven't yet.
  - eszed 3y ago
    I hadn't seen that before, so thanks for posting it. What a great story!
  - greesil 3y ago
    That was a great read. It was also interesting to read about what happened to the company. https://en.m.wikipedia.org/wiki/Thinking_Machines_Corporation https://en.m.wikipedia.org/wiki/Thinking_Machines_Corporatio... One thought I had while reading this was what areas of technologies are still open to amateurs.
sspiff 3y ago
As someone with very limited electrical experience, the more magic switch story instantly went "the second terminal of the switch is probably grounded to the switch casing" when they explained it only had one connected terminal. This is a very common thing in older automotive electronics, for example.
nosmokewhereiam 3y ago
Magic/more magic legend lives! I tell that to everyone experiencing a spooky troubleshooting!
miki123211 3y ago
There was a site with stories like these somewhere, I sadly can't remember the URL any more. I think the one that stuck out to me was the Soviet mainframe computer that would get weird bit flips almost every day, always at the exact same time. Somebody compared what was different about the days it didn't get bit flips on, it turns out those were the days on which a particular train didn't run, the computer was very close to a railway station. What train was it, you ask? The one transporting the (definitely perfectly safe to eat, definitely not filled to the brim with nuclear radiation) cow meat from Chernobyl. The radiation was intense enough to cause bit flips, I'm sure the quality of soviet components didn't help here either.
- nomel 3y ago
  Perhaps thedailywtf.com?
  - danlugo92 3y ago
    What was the one for Apple stories...?
    - timoteostewart 3y ago
      https://www.folklore.org/0-index.html https://www.folklore.org/0-index.html
- dr_orpheus 3y ago
  I think is the one you are looking for: https://beza1e1.tuxen.de/lore/index.html https://beza1e1.tuxen.de/lore/index.html Also posted on HN awhile back: https://news.ycombinator.com/item?id=23005140 https://news.ycombinator.com/item?id=23005140 Edit: yep, here are your Crash Cows: https://beza1e1.tuxen.de/lore/crash_cows.html https://beza1e1.tuxen.de/lore/crash_cows.html
2-3-7-43-1807 3y ago
i love those stories plus their detailed explanations because you can learn so much from them about technology, physics and even psychology.
redbell 3y ago
This is a true classic that never gets old! Discussed many times here in HN: 1. https://news.ycombinator.com/item?id=37576633 https://news.ycombinator.com/item?id=37576633 2. https://news.ycombinator.com/item?id=23775404 https://news.ycombinator.com/item?id=23775404 3. https://news.ycombinator.com/item?id=9338708 https://news.ycombinator.com/item?id=9338708

tombert 3y ago

The 500 mile email story is one of my favorite reminders that, fundamentally, we're still governed by the laws of physics. It's funny, but it's also a reminder that, while networks might be very fast, the latency is still going to be governed by the speed of light.

ck2 3y ago
Well laws of physics is what gave us radio in the first place. Some of my favorite video documentaries are on how it was theorized and then slowly developed over years and decades until they finally got to spark-gap transmitters. https://en.wikipedia.org/wiki/Timeline_of_radio https://en.wikipedia.org/wiki/Timeline_of_radio But just imagine listening to spark-gap morse code radio broadcasts for years as amateur and then suddenly someone does a broadcast test of actual voice (violin!) That must have been incredible to hear wirelessly. 24 December 1906 Reginald Fessenden, that was the leap that eventually gave us wifi https://en.wikipedia.org/wiki/Reginald_Fessenden https://en.wikipedia.org/wiki/Reginald_Fessenden
ortusdux 3y ago
If we are doing classic stories - Grace Hooper and the Nanosecond of wire https://www.youtube.com/watch?v=9eyFDBPk4Yw https://www.youtube.com/watch?v=9eyFDBPk4Yw https://americanhistory.si.edu/collections/nmah_692464 https://americanhistory.si.edu/collections/nmah_692464
hughesjj 3y ago
I actually like thinking about the exchange of physical information as a network propagation delay, and entanglement/coherence as a distributed consensus algorithm. They're kinda samey from a conceptual point of view (in my amateur opinion)

amelius 3y ago

I came here to see if someone posted that.

tiltowait 3y ago

I forgot all about the 500 miles story. My favorite line: > If the problem had had to do with the geography of the human recipient and not his mail server, I think I would have broken down in tears.

lamontcg 3y ago

and previously discussed: https://news.ycombinator.com/item?id=9338708 https://news.ycombinator.com/item?id=9338708

asadhaider 3y ago

First thing I thought of too. Anyone know if there a list of more articles similar to these three?

barryrandall 3y ago
DNS responses sent over UDP are often truncated if the response is too large. This manifests itself as "machine unreachable if name > x characters" sort of errors when you have really long FQDNs.
Tomte 3y ago
My wife has complained that open office will never print on Tuesdays!? https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161/comments/28 https://bugs.launchpad.net/ubuntu/+source/cupsys/+bug/255161...
fabatka 3y ago
I remember one (might have been a hn-er's comment, dunno) about the computer restarting when the toilet was flushed. Turns out it was due to voltage drop when a compressor turned on to refill the reservoir of the toilet.
- stavros 3y ago
  It was: https://news.ycombinator.com/item?id=39898272 https://news.ycombinator.com/item?id=39898272
- saalweachter 3y ago
  That's why in rural locales with spotty power it pays to have a UPS on any electronics -- you might not benefit much from 15-30 minutes of extra power in a day long blackout, but it keeps everything happy when the voltage fluctuates.
cyberax 3y ago
My personal example: VoIP phones stopping after the Asterisk server was up for 3 days. Reason: the server had IPv6 turned on, and it steadily accumulated privacy IPv6 addresses. These addresses were all sent in a packet describing the supported media endpoints, using UDP. And yep, eventually it overflowed the MTU and the phones couldn't handle the fragment reassembly.

sebtron 3y ago

Or the "Car allergic to vanilla ice cream" story [1]. [1] https://news.ycombinator.com/item?id=37584399 https://news.ycombinator.com/item?id=37584399

duxup 3y ago

I had a customer who used a line of sight system for extending their network across part of a city. I had a shortcut on my desktop with the weather for that town ready when they would inevitably call and blame our unrelated equipment for some problem.

scbrg 3y ago
I worked at a small, local ISP in the 90:ies that had a point to point link across the river, handling the dial up traffic from the telecom company we partnered with. Every few days, always at roughly the same time, all incoming dial up traffic would drop. A minute later, the customers could reconnect. It took a while before we realized that one of the huge passenger ferries that docked a short distance upstream was the cause. When it arrived and departed, its chimneys and possibly bridge and highest deck blocked LOS across the river.
dmurray 3y ago
I used to work in high-frequency trading. I had several tabs permanently open to the live weather radar feed for regions where we had microwave towers: the NE USA, the South of England, the Alps...
- seabass-labrax 3y ago
  I'm curious to know where your towers were. Do you know if they still exist? Were your microwave antennae co-located on other operators' towers (e.g. those for VHF radio), or did your company have towers all to itself?
  - dmurray 3y ago
    Without going into anything confidential - we had some of our own hardware, but generally rented capacity from firms like [0]. Some towers were custom built for HFT, some were shared with other types of users. A famous blog post investigating some of the towers as an outsider, at [1], will be of interest to you. If you want to guess where they are, get a globe, find the datacentres where electronic exchanges operate (it's not a secret: Chicago, New Jersey, London, Tokyo, Frankfurt, Zurich...) and draw the straightest possible lines between pairs of them. Microwaves don't cross the ocean. [0] https://www.mckay-brothers.com/ https://www.mckay-brothers.com/ [1] https://sniperinmahwah.wordpress.com/2014/09/25/hft-in-my-backyard-ii/ https://sniperinmahwah.wordpress.com/2014/09/25/hft-in-my-ba...

FergusArgyll 3y ago

Boy did that [0] send me down a long rabbit hole [0] magic-story

vikingerik 3y ago

My recent version: I was playing a pinball game in an arcade. One particular ramp shot was registering earlier in the day and then stopped working. Eventually I realized that the sensor is an optical beam, and the receiver happened to be in direct sunlight coming in through a window! So it was continuously receiving infrared and would never report the beam being blocked by a pinball. Sure enough, it started working again once the sun angle changed by a few more degrees.

lupusreal 3y ago
You missed an opportunity to cheat the machine by waving your hand between it and the sun. ;)
- vikingerik 3y ago
  Heh, but not exactly. If I blocked the sun, the receiver still would have been picking up the real beam. I would have had to block the sun _and_ make the shot with a pinball at the same instant... which is just playing the game normally with extra steps.
yencabulator 3y ago
I have an optical smoke detector that will give (very loud) false alarms if a sun beam can bounce off a windowsill onto it. It works great if the curtain is closed. Debugging that took a few early sunrises.

freedomben 3y ago

Oh man, this is one of my favorite lines of all time: > "Anyway, I asked one of the geostatisticians to look into it--" > "Geostatisticians..." > "--yes, and she's produced a map showing the radius within which we can send email to be slightly more than 500 miles. 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." I adore when experts use their expertise to analyze real-world things like this and provide ridiculously thorough explanations :-D

fsckboy 3y ago
it's a useful analysis. Nobody thought of router hops, but this pattern is pretty much what you'd expect, so it was a very good hint.
neilv 3y ago
My favorite story kinda of this nature, of an expert as alien intelligence, was Feynmann's calculations about computer architecture of the Connection Machine: https://longnow.org/essays/richard-feynman-connection-machine/ https://longnow.org/essays/richard-feynman-connection-machin... It's a few paragraphs, maybe too much to quote, but the bulk of it starts with: > By the end of that summer of 1983, Richard had completed his analysis of the behavior of the router, and much to our surprise and amusement, he presented his answer in the form of a set of partial differential equations. To a physicist this may seem natural, but to a computer designer, treating a set of boolean circuits as a continuous, differentiable system is a bit strange. [...] Our discrete analysis said we needed seven buffers per chip; Feynman's equations suggested that we only needed five. We decided to play it safe and ignore Feynman. Guess who was right. The whole essay is worth reading, if you haven't yet.
- eszed 3y ago
  I hadn't seen that before, so thanks for posting it. What a great story!
- greesil 3y ago
  That was a great read. It was also interesting to read about what happened to the company. https://en.m.wikipedia.org/wiki/Thinking_Machines_Corporation https://en.m.wikipedia.org/wiki/Thinking_Machines_Corporatio... One thought I had while reading this was what areas of technologies are still open to amateurs.

sspiff 3y ago

As someone with very limited electrical experience, the more magic switch story instantly went "the second terminal of the switch is probably grounded to the switch casing" when they explained it only had one connected terminal. This is a very common thing in older automotive electronics, for example.

nosmokewhereiam 3y ago

Magic/more magic legend lives! I tell that to everyone experiencing a spooky troubleshooting!

miki123211 3y ago

There was a site with stories like these somewhere, I sadly can't remember the URL any more. I think the one that stuck out to me was the Soviet mainframe computer that would get weird bit flips almost every day, always at the exact same time. Somebody compared what was different about the days it didn't get bit flips on, it turns out those were the days on which a particular train didn't run, the computer was very close to a railway station. What train was it, you ask? The one transporting the (definitely perfectly safe to eat, definitely not filled to the brim with nuclear radiation) cow meat from Chernobyl. The radiation was intense enough to cause bit flips, I'm sure the quality of soviet components didn't help here either.

nomel 3y ago
Perhaps thedailywtf.com?
- danlugo92 3y ago
  What was the one for Apple stories...?
  - timoteostewart 3y ago
    https://www.folklore.org/0-index.html https://www.folklore.org/0-index.html
dr_orpheus 3y ago
I think is the one you are looking for: https://beza1e1.tuxen.de/lore/index.html https://beza1e1.tuxen.de/lore/index.html Also posted on HN awhile back: https://news.ycombinator.com/item?id=23005140 https://news.ycombinator.com/item?id=23005140 Edit: yep, here are your Crash Cows: https://beza1e1.tuxen.de/lore/crash_cows.html https://beza1e1.tuxen.de/lore/crash_cows.html

2-3-7-43-1807 3y ago

i love those stories plus their detailed explanations because you can learn so much from them about technology, physics and even psychology.

redbell 3y ago

This is a true classic that never gets old! Discussed many times here in HN: 1. https://news.ycombinator.com/item?id=37576633 https://news.ycombinator.com/item?id=37576633 2. https://news.ycombinator.com/item?id=23775404 https://news.ycombinator.com/item?id=23775404 3. https://news.ycombinator.com/item?id=9338708 https://news.ycombinator.com/item?id=9338708