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Calling it irrelevant just because you can't travel there is short-sighted. We could still learn a lot just by watching the broadcasts of another civilization,

by Fizzer 14y ago

Calling it irrelevant just because you can't travel there is short-sighted. We could still learn a lot just by watching the broadcasts of another civilization, even if they're already long gone.

rewind 14y ago
And just knowing they exist would be incredibly exciting, even if there was zero chance that we could directly contact them in the span of our entire existence.
snowwrestler 14y ago
The distances are so great that the broadcasts of another civilization would attenuate to undetectable levels before they could reach us.
vibrunazo 14y ago
Out of all infinite amount of different methods to communicate and broadcast themselves they could possibly be using. Including the ones we didn't even discover yet. Assuming they're using the same ones humans just found out in recent history. The ones SETI is measuring. Even then, assuming it's formatted in a way we would decipher and be able to understand its structure (as in Carl Sagan's movie). That just sounds so improbable. Even if they are broadcasting it, we're probably listening to it with the wrong technology. Even if we happen to be lucky of listening with the "right" technology. We probably wouldn't be able to tell it from random noise. I find it extremely unlikely humans will ever be able to watch alien broadcasts during our existence in the universe.
- dexter313 14y ago
  "Even if they are broadcasting it, we're probably listening to it with the wrong technology. Even if we happen to be lucky of listening with the "right" technology. We probably wouldn't be able to tell it from random noise." That's why you start by blasting prime numbers on all em frequencies for 5 years.
- lusr 14y ago
  I don't think there are many different ways to encode meaningful information. We all live in the same universe and I see no reason to believe that intelligent alien life won't be intellectually quite similar to us. While tricky without context, decoding extraterrestrial signals will inevitably produce something of interest (images, audio) even if understanding e.g. the audio itself will be tricky. That being said, while I suspect that meaningful, structured information will be, by definition, structured and therefore obvious to spot in a broadcast, the real problem is that these transmissions are likely to be (a) compressed and/or (b) encrypted. While compression formats may reveal a few hints that there is some structured information present, encrypted data will be all but impossible to distinguish from random transmissions. We may be picking up transmissions from alien life but be unaware simply because the data is encrypted. I have no idea what proportion of our broadcast signals are encrypted today, but I suspect it's a fairly significant and growing proportion (privacy and intellectual property concerns being the primary reasons).
  - mistermann 14y ago
    > While tricky without context, decoding extraterrestrial signals will inevitably produce something of interest (images, audio) even if understanding e.g. the audio itself will be tricky. Serious question: How is it presumably simple to decode images and audio, but difficult to understand the audio? Is it because one can assume image representation would tend towards mathematical efficiency, but spoken languages do not? >While compression formats may reveal a few hints that there is some structured information present, encrypted data will be all but impossible to distinguish from random transmissions. We may be picking up transmissions from alien life but be unaware simply because the data is encrypted. I would think that encrypted transmissions would be easily distinguishable from background white noise, no? My thinking is, you have the general random noise of space, and then you would have something obviously different, is that totally not the case?
    - deleted 14y ago
      [deleted]
    - lusr 14y ago
      Yes, I believe that images (encodings of electromagnetic radiation of particular wavelengths) and audio (encodings of mechanical waves of pressure) are universal concepts aliens are also likely to be familiar with, whereas understanding the information encoded within the transmission requires interpretation within a context we are highly unlikely to have here on Earth. This is just my intuition and speculation but I would guess somebody could formalise some support in terms of Kolmogorov complexity (http://en.wikipedia.org/wiki/Kolmogorov_complexity http://en.wikipedia.org/wiki/Kolmogorov_complexity): there are only so many ways to represent an image or audio, and over time an intelligent race will discover the least complex method and use it. Therefore, alien races of equivalent levels of technical advancement in a given field should be able to decode raw (uncompressed and unencrypted) transmissions of common types of information (images, audio). Any additional complexity on top of this method will probably be quite structured, e.g. with television signals we have portions of the signal that are blank because during that time the CRT of old televisions would be retracing and not displaying data. (Actually, I believe these "dead" portions of the video signal are sometimes used to send additional structured data, e.g. Teletext, which would make the structure of the signal even more apparent.) I suspect it'll be much easier to look at alien video transmissions and figure out what they're about than trying to listen do the same with audio transmissions because video would provide objective context (assuming it's not just a video of talking alien heads, or whatever the equivalent of a "head" for them would be). With respect to encrypted transmissions, if the entire protocol is encrypted from start to finish, and you're using the right cipher* then no, you can't distinguish encrypted data from random noise. This is the principle behind TrueCrypt's hidden volumes (http://www.truecrypt.org/docs/?s=hidden-volume http://www.truecrypt.org/docs/?s=hidden-volume). * What's the right cipher? So far no nobody has found a distinguisher for AES, and that's in common use, so that's probably good enough to make an alien race blind to us; i.e. we could be picking up signals from a race as sophisticated as c. 1998 humans (http://en.wikipedia.org/wiki/Advanced_Encryption_Standard http://en.wikipedia.org/wiki/Advanced_Encryption_Standard) without realising it.
ygmelnikova 14y ago
What lessons are to be learned from the alien version of "I Love Lucy"?

by Fizzer 14y ago

Calling it irrelevant just because you can't travel there is short-sighted. We could still learn a lot just by watching the broadcasts of another civilization, even if they're already long gone.

rewind 14y ago

And just knowing they exist would be incredibly exciting, even if there was zero chance that we could directly contact them in the span of our entire existence.

snowwrestler 14y ago

The distances are so great that the broadcasts of another civilization would attenuate to undetectable levels before they could reach us.

vibrunazo 14y ago

Out of all infinite amount of different methods to communicate and broadcast themselves they could possibly be using. Including the ones we didn't even discover yet. Assuming they're using the same ones humans just found out in recent history. The ones SETI is measuring. Even then, assuming it's formatted in a way we would decipher and be able to understand its structure (as in Carl Sagan's movie). That just sounds so improbable. Even if they are broadcasting it, we're probably listening to it with the wrong technology. Even if we happen to be lucky of listening with the "right" technology. We probably wouldn't be able to tell it from random noise. I find it extremely unlikely humans will ever be able to watch alien broadcasts during our existence in the universe.

dexter313 14y ago
"Even if they are broadcasting it, we're probably listening to it with the wrong technology. Even if we happen to be lucky of listening with the "right" technology. We probably wouldn't be able to tell it from random noise." That's why you start by blasting prime numbers on all em frequencies for 5 years.
lusr 14y ago
I don't think there are many different ways to encode meaningful information. We all live in the same universe and I see no reason to believe that intelligent alien life won't be intellectually quite similar to us. While tricky without context, decoding extraterrestrial signals will inevitably produce something of interest (images, audio) even if understanding e.g. the audio itself will be tricky. That being said, while I suspect that meaningful, structured information will be, by definition, structured and therefore obvious to spot in a broadcast, the real problem is that these transmissions are likely to be (a) compressed and/or (b) encrypted. While compression formats may reveal a few hints that there is some structured information present, encrypted data will be all but impossible to distinguish from random transmissions. We may be picking up transmissions from alien life but be unaware simply because the data is encrypted. I have no idea what proportion of our broadcast signals are encrypted today, but I suspect it's a fairly significant and growing proportion (privacy and intellectual property concerns being the primary reasons).
- mistermann 14y ago
  > While tricky without context, decoding extraterrestrial signals will inevitably produce something of interest (images, audio) even if understanding e.g. the audio itself will be tricky. Serious question: How is it presumably simple to decode images and audio, but difficult to understand the audio? Is it because one can assume image representation would tend towards mathematical efficiency, but spoken languages do not? >While compression formats may reveal a few hints that there is some structured information present, encrypted data will be all but impossible to distinguish from random transmissions. We may be picking up transmissions from alien life but be unaware simply because the data is encrypted. I would think that encrypted transmissions would be easily distinguishable from background white noise, no? My thinking is, you have the general random noise of space, and then you would have something obviously different, is that totally not the case?
  - deleted 14y ago
    [deleted]
  - lusr 14y ago
    Yes, I believe that images (encodings of electromagnetic radiation of particular wavelengths) and audio (encodings of mechanical waves of pressure) are universal concepts aliens are also likely to be familiar with, whereas understanding the information encoded within the transmission requires interpretation within a context we are highly unlikely to have here on Earth. This is just my intuition and speculation but I would guess somebody could formalise some support in terms of Kolmogorov complexity (http://en.wikipedia.org/wiki/Kolmogorov_complexity http://en.wikipedia.org/wiki/Kolmogorov_complexity): there are only so many ways to represent an image or audio, and over time an intelligent race will discover the least complex method and use it. Therefore, alien races of equivalent levels of technical advancement in a given field should be able to decode raw (uncompressed and unencrypted) transmissions of common types of information (images, audio). Any additional complexity on top of this method will probably be quite structured, e.g. with television signals we have portions of the signal that are blank because during that time the CRT of old televisions would be retracing and not displaying data. (Actually, I believe these "dead" portions of the video signal are sometimes used to send additional structured data, e.g. Teletext, which would make the structure of the signal even more apparent.) I suspect it'll be much easier to look at alien video transmissions and figure out what they're about than trying to listen do the same with audio transmissions because video would provide objective context (assuming it's not just a video of talking alien heads, or whatever the equivalent of a "head" for them would be). With respect to encrypted transmissions, if the entire protocol is encrypted from start to finish, and you're using the right cipher* then no, you can't distinguish encrypted data from random noise. This is the principle behind TrueCrypt's hidden volumes (http://www.truecrypt.org/docs/?s=hidden-volume http://www.truecrypt.org/docs/?s=hidden-volume). * What's the right cipher? So far no nobody has found a distinguisher for AES, and that's in common use, so that's probably good enough to make an alien race blind to us; i.e. we could be picking up signals from a race as sophisticated as c. 1998 humans (http://en.wikipedia.org/wiki/Advanced_Encryption_Standard http://en.wikipedia.org/wiki/Advanced_Encryption_Standard) without realising it.

ygmelnikova 14y ago

What lessons are to be learned from the alien version of "I Love Lucy"?