<p>Ordinarily, I'd think this was out of scope. However, there's an interesting series of papers involving Madhu Sudan, Brendan Juba and Oded Goldreich on what they call universal semantic communication (or how to talk with aliens). The papers are here: <a href="http://people.csail.mit.edu/madhu/bib.html#juba" rel="nofollow">one</a>, <a href="http://people.csail.mit.edu/madhu/bib.html#usc2" rel="nofollow">two</a>, <a href="http://people.csail.mit.edu/madhu/bib.html#beliefs" rel="nofollow">three</a>.</p>

CC BY-SA 3.0
2011-08-24T18:11:58.107Z
Thanks for the links. I didn't really understand 2 and 3, and 1 relies on a certain dialogue between the involved parties, so it doesn't seem to apply here. So I guess it's impossible to restore the encoding without sufficient documentation?
Hackworth
CC BY-SA 3.0
2011-08-24T15:43:03.900Z
2011-08-24T15:43:03.900Z
Suresh Venkat
<p>While browsing I've stumbled over the Phoenix Mars lander</p>

<p><a href="http://en.wikipedia.org/wiki/Phoenix_(spacecraft)#Phoenix_DVD" rel="nofollow">http://en.wikipedia.org/wiki/Phoenix_(spacecraft)#Phoenix_DVD</a></p>

<p>and it says that the craft contains a DVD with all kinds of information on it.</p>

<p>Now my question would be: If the disc is made to last centuries or even millenia, how would one make sure that the digital information can be decoded in a future when all knowledge about present-day encoding must be assumed long forgotten?</p>

<p>I'm not even talking about building a working DVD player; if all else fails, take a strong microscope and extract the bits the hard way. </p>

<p>It's about, how would I, as a future scientist, interpret the bits such that the original meaning is restored, and how would I know that I've picked the right decoding? "Digital Memory Loss" has been recognized as a major problem already, and it's only been a few decades since we earnestly started producing (and forgetting!) mass quantities of digital information.</p>

CC BY-SA 3.0
2011-08-24T18:18:05.103Z
related: http://cstheory.stackexchange.com/q/4988/1037
Artem Kaznatcheev
<it.information-theory>
Long-term data encoding, Phoenix Mars DVD
Hackworth
# Long-term data encoding, Phoenix Mars DVD

(Asked by: username_0 on 2011-08-24)

While browsing I've stumbled over the Phoenix Mars lander

<http://en.wikipedia.org/wiki/Phoenix_(spacecraft)#Phoenix_DVD>

and it says that the craft contains a DVD with all kinds of information on it.

Now my question would be: If the disc is made to last centuries or even millenia, how would one make sure that the digital information can be decoded in a future when all knowledge about present-day encoding must be assumed long forgotten?

I'm not even talking about building a working DVD player; if all else fails, take a strong microscope and extract the bits the hard way.

It's about, how would I, as a future scientist, interpret the bits such that the original meaning is restored, and how would I know that I've picked the right decoding? "Digital Memory Loss" has been recognized as a major problem already, and it's only been a few decades since we earnestly started producing (and forgetting!) mass quantities of digital information.

**Tags:** it.information-theory
> **Comments:**
> **username_1**: related: http://cstheory.stackexchange.com/q/4988/1037  

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## 1 answers

### Answer by username_2 on 2011-08-24. Score: 5

Ordinarily, I'd think this was out of scope. However, there's an interesting series of papers involving Madhu Sudan, Brendan Juba and Oded Goldreich on what they call universal semantic communication (or how to talk with aliens). The papers are here: [one](http://people.csail.mit.edu/madhu/bib.html#juba), [two](http://people.csail.mit.edu/madhu/bib.html#usc2), [three](http://people.csail.mit.edu/madhu/bib.html#beliefs).

> **Comments:**
> **username_0**: Thanks for the links. I didn't really understand 2 and 3, and 1 relies on a certain dialogue between the involved parties, so it doesn't seem to apply here. So I guess it's impossible to restore the encoding without sufficient documentation?  

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