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We can't send email more than 500 miles (2002)

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Re: We can't send email more than 500 miles (2002)

#71

Post by divbzero »

ornornor wrote: post #64
wuster wrote: post #59

Best part of reading this is coming away having learned the existence of units the CLI. How did I spend 20 years on the shell and not have needed or discovered this?

Be aware that currencies are stuck with rates from several years ago and don’t update.

I wonder if this could be addressed with periodic updates.

Re: We can't send email more than 500 miles (2002)

#72

Post by thyrsus »

I've had enough years to become wiser, become a fanatic for configuration management, and get over the embarrassment: I'm the consultant that screwed things up. Some background: the Stat department was running a variety of systems besides the Solaris workstations, and there was, within UNC-CH, a separate support organization that was cheaper and more comfortable with Microsoft products where Stat was sending their support dollars. When that organization needed Unix support, they called my employer, Network Computing Solutions, and I showed up.

There was effectively no firewall at UNC-CH at the time (something something academic freedom something something), and the Stat Solaris machines were not being regularly patched. Uninvited guests had infested them, and it appeared the most likely entry point was sendmail - at the time, it was the most notorious vulnerability on the internet. Since my preference to wipe and reload was unacceptable - too much downtime and too many billable hours - the obvious thing to do was update sendmail. The rest is history.

Re: We can't send email more than 500 miles (2002)

#73

Post by divbzero »

frandroid wrote: post #31
comex wrote: post #27

Earlier quoted context omitted.

The FAQ addresses this: https://www.ibiblio.org/harris/500milemail-faq.html

Since the story has been posted umpteenth times, this is what should be posted these days. Very entertaining, thanks!

Yes! Thank you GP this too was my first time reading that follow-up FAQ.

Re: We can't send email more than 500 miles (2002)

#74

Post by ornornor »

divbzero wrote: post #71
ornornor wrote: post #64

Earlier quoted context omitted.

Be aware that currencies are stuck with rates from several years ago and don’t update.

I wonder if this could be addressed with periodic updates.

I didn’t look too deep into it, my understanding was that the source it uses to update itself has been taken offline. There are workarounds involving data massaging and a cron but honestly that’s a lot more work than typing “1000 chf to usd” into ddg and getting the converted amount. But if you know something I don’t, maybe you could share for everyone’s benefit?

Re: We can't send email more than 500 miles (2002)

#75

Post by chongli »

curiousgal wrote: post #68
abeppu wrote: post #19

The ending of this makes it sound super clean. 3 ms * speed of light => ~560 miles. "It all makes sense!" But ... isn't the speed of light through fiber actually like 2/3 of the speed of light in a vacuum? And that fiber isn't going to be laid out in a straight line exactly to the destination. So I think really there must have been a fair bit of uncertainty around that ~3ms to abort a connection.

I am surprised that signals travel faster in copper (3c/4) than in fiber (2c/3), anyone has an explanation?

The number for copper is not a fixed quantity, it varies with the type of cable. Electric fields are outside of the copper wire, not inside. The copper conductor acts as a wave guide for the electromagnetic wave. So it turns out that things around the cable have an effect on the speed of propagation [1], particularly the insulator. Bare copper wire in a vacuum would be very close to c. In the case of fibre, the issue is index of refraction.

[1] https://en.wikipedia.org/wiki/Velocity_factor

Re: We can't send email more than 500 miles (2002)

#76

Post by rlonn »

thyrsus wrote: post #72

I've had enough years to become wiser, become a fanatic for configuration management, and get over the embarrassment: I'm the consultant that screwed things up. Some background: the Stat department was running a variety of systems besides the Solaris workstations, and there was, within UNC-CH, a separate support organization that was cheaper and more comfortable with Microsoft products where Stat was sending their su…

I read this story years ago and thought it was hilarious. Could've happened to anyone. In my book you're a near-celebrity and it's great that you can verify the story! Thanks for making things a little more interesting and a lot more fun :)

Re: We can't send email more than 500 miles (2002)

#77

Post by cranium »

wuster wrote: post #59

Best part of reading this is coming away having learned the existence of units the CLI. How did I spend 20 years on the shell and not have needed or discovered this?

One thing I got bitten by was the handling of Fahrenheit/Celsius, because it's a non-linear conversion between the two. When you ask to convert `10 degC` to `degF` you get 18, which is the delta of ºF corresponding to increment of 10ºC. To get the absolute temperature, you have to ask to convert `tempC(10)` to `tempF` which is 50, as expected.

https://www.gnu.org/software/units/

Re: We can't send email more than 500 miles (2002)

#78

Post by throwaway744678 »

ornornor wrote: post #64
wuster wrote: post #59

Best part of reading this is coming away having learned the existence of units the CLI. How did I spend 20 years on the shell and not have needed or discovered this?

Be aware that currencies are stuck with rates from several years ago and don’t update.

Looking at the source of the default configuration (cat /usr/share/misc/units.lib), I believe it only defines conversions for currencies that are pegged to another one (mainly to EUR or USD).

    You have: 10 franc
    You want: dollar
    conformability error
     1.5244902 euro
     1 usdollar
    You have: 10 franc
    You want: euro
     * 1.5244902
     / 0.655957

Re: We can't send email more than 500 miles (2002)

#79

Post by ElFitz »

akeruu wrote: post #12
anamexis wrote: post #4

Earlier quoted context omitted.

A few more: https://news.ycombinator.com/item?id=12778904 https://news.ycombinator.com/item?id=21578606 https://news.ycombinator.com/item?id=16384158 https://news.ycombinator.com/item?id=16285093 https://news.ycombinator.com/item?id=12997568 https://news.ycombinator.com/item?id=3802458 https://news.ycombinator.com/item?id=123489 https://news.ycombinator.com/item?id=385068 https://news.ycombinator.com/item?id=2701063…

Yes, this story gets posted a lot, and many of us might know it, but at the same time, I like to think about the ones that didn't. They will learn something new today. XKCD said it better than I could: https://xkcd.com/1053/

I did. And it was not only informative but also hilarious.

Re: We can't send email more than 500 miles (2002)

#80

Post by zerocrates »

ornornor wrote: post #64
wuster wrote: post #59

Best part of reading this is coming away having learned the existence of units the CLI. How did I spend 20 years on the shell and not have needed or discovered this?

Be aware that currencies are stuck with rates from several years ago and don’t update.

I'm tempted to say it shouldn't even attempt to support currency conversion, as constantly in flux as it is.
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