How the Voyager space probe's golden record was made
newyorker.com
newyorker.com
The first few images stored on the disk are interesting. They establish our location in the Milky Way as well as our math and physics.
You're right about it being a message to ourselves though. There's an essentially 0% chance that anyone other than humans will ever experience it, and a 0% chance that we'd ever know if they do. Still think they did a good job.
What better could we have chosen to communicate, given the same limitations of format?
For instance, consider the "color" images we included. In reality, each color image is actually just 3 black and white images taken with slightly difference response curves. Granted, the solar spectrum image should give them enough information to determine these curves; but, unless they have an identical visual system to us, they would still not be able to reconstruct what they would see as a true color image. If we really wanted them to see in color, we could have chosen more appropriate response curves to take our images from. Regardless, the space would have been better spent including more images. However, from a PR standpoint, including color images was likely a very good move.
Simmilarly, I do not any justification for including spoken greetings. Assuming the correctly decode them as sounds (which I think is reasonable), and understand them to be a language (less reasonable) I don't see how they could decipherer anything meaningful from them (except, perhaps, the phonetic inventory of human languages). Similarly, I would expect aliens to do little more than scratch their heads at the inclusion of 90 minutes of music.
For the spoken language, there is likely not enough information to decode its meaning. But its inclusion together with images of us might lead them to understand how we communicate by voice. The sounds of animals and humans may be similar to other lifeforms discovered. Music as well may be something which is common to many forms of intelligent life. It would probably not be possible to understand much of the contents, but observers might be able to relate to the emotions in the music (even though they may not map directly to ours). In any case, with art much of the value lies in the interpretation. As long as content is presented which they would care to judge as art, they may see value in it.
I found this line from the transcript of the President's speech interesting:
> This is a present from a small distant world...
That small distant world will almost certainly be the closest thing to the probe if it is found by some spacefaring civilization.
JPL says they'll be at a distance that's halfway to Proxima Centauri within about 40,000 years, which is a mere instant in cosmological time.
In the article Tim Ferris mentions that Ann Druyan was his fiancee at the time. I suppose it's common knowledge that she was also Carl Sagan's third (and final) wife.
NASA's Voyager, the Love Story [1] reveals that their affair grew out of and became an integral part of the project:
Just how do you stumble upon a woman in love and record her brain waves for an interstellar message? It helps when the young woman is herself a member of the recording team: Ann Druyan.
On June 1, 1977, Carl and I shared a wonderfully important phone call," she recalls. Without the aid of a date or even a romantic moment alone, the two had fallen in love during the mad rush to complete the Golden Record. "We decided to get married. It was a Eureka! moment for both of us—the idea that we could find the perfect match. It was a discovery that has been reaffirmed in countless ways since."
"My feelings as a 27 year old woman, madly fallen in love, they're on that record,” says Druyan. "It's forever. It'll be true 100 million years from now. For me Voyager is a kind of joy so powerful, it robs you of your fear of death."
According to her recent interview with LA Times they were a bit more circumspect about their Eureka moment than the NASA article would suggest:
During this period, she and Sagan, who was then married to his second wife, also realized they were "madly in love." Reluctant to jeopardize the mission, the pair waited until Voyager 1 had successfully launched before breaking the news to their significant others.
I feel this adds an extra dimension to this matter-of-fact statement from Ferris's article:
We disbanded soon after I delivered the metal master to Los Angeles, making ours a proud example of a federal project that evaporated once its mission was accomplished.
[1] https://science.nasa.gov/science-news/science-at-nasa/2011/2...
[2] http://www.latimes.com/entertainment/tv/la-et-st-ann-druyan-...
"All signals with content entirely below the Nyquist frequency (half the sampling rate) are captured perfectly and completely by sampling; an infinite sampling rate is not required. Sampling doesn't affect frequency response or phase. The analog signal can be reconstructed losslessly, smoothly, and with the exact timing of the original analog signal."
Analog reproduction is far less complex and easier to explain in pictures to an unknown entity that might find it. Figure that they'll need to build what effectively amounts to a record player to play the thing back. In addition there was no digital technology of the time with a large enough capacity to store what we sent, or that was durable enough to deal with an unknown time in space.
Quality of the reproduction is not a consideration.
Now I wonder how long it will take until the memory of the computer is destroyed by cosmic radiation. I guess the old method of a gold plated record would be more durable.