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Comment by jacobush | Hacker News Reader

... how. I don't get it.

Unix time starts counting upwards from zero on January 1st 1970. It's a joke. If they had Unix computers in the lander they would have had to use negative time since the first moon landing happened in 1969.

In Vernor Vinge's far future novel _A Deepness in the Sky_, there is a mention of a "programmer-archaeologist" who digs deep into layers and layers of legacy software of spaceships; it's tens of thousands of years of stuff built on top of each other.

It's mentioned that the deepest layers count time in seconds from the moment that humanity first landed on the moon of its home planet.

I very highly recommend that book, by the way. My favorite science fiction book I've ever read. Anyone else love it?

I’m currently reading the book precisely based on a recommendation from HN. It’s a great book indeed.

I would also recommend Vernor Vinge's earlier work, A Fire Upon the Deep.

It features a galaxy wide group of alien civilizations that communicate by means of a system that greatly resembles Usenet newsgroups.

It either won or was nominated for most of the major science fiction awards.

Oh, I actually confused the two! A Fire Upon the Deep is my all time favorite, A Deepness in the Sky is close behind though.

I've been looking for books with similar ideas for a long time... would you (or anyone else) know any? The ideas in the two books are really amazing.

Here are some works I'm fond of from authors who deal in technology and whose works have also taken the top science fiction awards.

Neal Stephenson's Snow Crash and The Diamond Age.

Greg Bear's Moving Mars, Anvil of Stars, and Eon.

John Barnes' A Million Open Doors, and Mother of Storms.

In fact, there’s an comment to the effect that the actual start time is about a million and a half seconds after the moon landing — which means the original time system is Unix-based...

I just love the title "Programmer-at-Arms." Some of the seat-of-the-pants work we do in industrial automation, making changes to a machine's operating logic while it's actually running in production, feels just like that.

If NASA are anything like us, their epoch is January 1, 1958:

https://public.ccsds.org/Pubs/301x0b4e1.pdf

Thanks for that info. "Us" there means:

"Founded in 1982 by the major space agencies of the world, the CCSDS is a multi-national forum for the development of communications and data systems standards for spaceflight."

And indeed, the epoch:

"The CCSDS-Recommended epoch is that of 1958 January 1 (TAI) and the recommended time unit is the second, using TAI as reference time scale, for use as a level 1 time code. This time code is not UTC-based and leap-second corrections do not apply."

I'm guessing it's a bad joke about Unix time (starts in 1970)

Except it's a really good joke.

The UNIX epoch is midnight, January 1st, 1970 while the landing on the moon was 1969-07-20.

NASA / ESA epoch is 1 January 1958:

https://public.ccsds.org/Pubs/301x0b4e1.pdf

> he UNIX epoch is midnight, January 1st, 1970

in UTC.

But after 10,000 years (or whatever) that distinction might be lost.

It’s about the unix epoch starting in 1970.

-_-

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