Wednesday, December 15, 2010

The Other, Other Voyager

No, not that Voyageur.

But this one:

The Voyager 1 spacecraft is a 722-kilogram (1,592 lb) robotic space probe of the outer Solar System and beyond, launched by NASA on September 5, 1977. It still receives signals and commands from, and transmits information to Earth, currently pursuing its extended mission to locate and study the boundaries of the Solar System.
Above are the "family portrait" photos of our solar system, which Voyager is responsible for.

It is estimated that both Voyager craft have sufficient electrical power to operate their radio transmitters until at least 2025, which will be over 48 years after launch.

The Voyager, it was just announced, has crossed the terminal shock and entered the heliosheath.

Our sun gives off a stream of charged particles that form a bubble known as the heliosphere around our solar system. The solar wind travels at supersonic speed until it crosses a shockwave called the termination shock. At this point, the solar wind dramatically slows down and heats up in the heliosheath. 

Anyway, this blog post isn't really about the Voyager either. It's about the other voyager on the Voyager; the Golden Record.

Click to enlarge. Actually, that works for any picture on the blog, 9/10.

So, what is the Golden Record? Really glad you asked.

The Golden Records (actually, as far as I understand, there are three: 1 on Voyager 1, 1 on Voyager 2, and 1 is locked up somewhere safely on earth) are phonograph records which were included aboard both Voyager spacecraft, which were launched in 1977. They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them. The Voyager spacecraft are not heading towards any particular star, but Voyager 1 will be within 1.6 light years of the star AC+79 3888 in the Ophiuchus constellation in about 40,000 years.

The contents of the record were selected for NASA by a committee chaired by Carl Sagan of Cornell University. Dr. Sagan and his associates assembled 116 images and a variety of natural sounds, such as those made by surf, wind, and thunder, and animal sounds, including the songs of birds and whales. To this they added musical selections from different cultures and eras, spoken greetings in fifty-five languages, and printed messages from President Jimmy Carter.

The collection of images includes many photographs and diagrams both in black and white and color. The first images are of scientific interest, showing mathematical and physical quantities, the solar system and its planets, DNA, and human anatomy and reproduction. Care was taken to include not only pictures of humanity, but also some of animals, insects, plants and landscapes.

Other sounds of Earth on the record include both natural noises, such as a rainstorm and a chimpanzee, and human-created ones, such as a train and a kiss.

Pictures can be encoded into information on a record. The Voyager golden record has 116 pictures.

Some images contain indications of chemical composition. All measures used on the pictures are defined in the first few images using physical references that are likely to be consistent anywhere in the universe.

The musical selection is also varied, featuring artists such as Beethoven, Mozart, Bach, and Stravinsky and Chuck Berry.

Wasn't this a Prince album cover?

Download the entire Golden Record contents here (torrent). For a quick look, click on the following links for audio of the 55 greetings in different languages, the music from earth, the sounds from earth, and some of the photographs included.

Each image on the record took up about 12 revolutions. Of the 116 images, about 20 were in colour. Colour was achieved by recording every colour image three times in succession, one greyscale image each for the red, green and blue portions; this gave a combined colour depth of 12 bits or 4096 colours (individual image depth was 16 shades of grey, or 4 bits). Combining the three would give the original image.

The first colour image was of the solar spectrum, intended as a calibration tool so the viewer could establish colour settings for viewing the rest of the colour images. It was believed any species capable of intercepting either Voyager probe would understand a solar spectrum.


Ok, let's do some math and see where/how this thing is going...

Seriously, this thing is travelling at ~17 km/s, 61,000 km/hr, and making no headway. Really. About 534 360 000 km/year, or half a billion km/year.

Let's take the 4th closest start from us, Wolf 359. It's in the Leo constellation (remember the Leonids?) and is 7.7 light years away.

First,1 light year = ~9460528472580.8 km, or 9.4605284 × 1012 km. 

So 7.7 Light Years = 72847624638872.16 km, or 7.28476246 x 1013 km. 

To put it another way, the Voyager has travelled 17.4 billion kilometers. How many light years is that?

But, 17400000000 km = only 0.001839 Light Years.

Not even 1/2 of 1% of a light year. INSANE! One light year is 9460000000000 km (or 9.46 trillion km).

SO, to travel 7.7 light years at its current pace, it's going to have to travel for (approximately, given I've done everything right.. ) 138,160 years to get there, or, to put it in perspective,* about the length of time Homo Sapiens have been around.

*Not really.

So, a long time, but not that long I suppose, when put into an even greater perspective. 

In about 40,000 years both craft should coast to within 1.7 light-years (Voyager 1) or 1.1 light-years (Voyager 2) of AC+79 3888, a fourth magnitude star. Voyager 2 should pass a similar distance from another star (AC -24 2833-183) 100,000 years later in Sagittarius, and about 375,000 years after that, Voyager 1 will pass within 1.5 light-years of AM +21 652 in the constellation of Taurus.

The records on board were meant to survive for a billion years (constructed of gold-plated copper and is encased in aluminum), in the hope that some day, against enormous odds, they might cross paths with an alien civilization.

There is also an ultra-pure sample of the isotope uranium-238 electroplated on the record's cover. Uranium-238 has a half-life of 4.51 billion years. It is possible that a civilization that encounters the record will be able to use the ratio of remaining uranium to daughter elements to determine the age of the record.


Ok, so, back to the actual record.
The record cover.

Each record is encased in a protective aluminum jacket, together with a cartridge and a needle to play them. The cover of the record is pretty impressive. It is the key to using and understanding the information. The cover of the Golden Records tells:
  • How to play the record
  • How to get images from the record
  • Where our solar system is, mapped from several known pulsars
  • The length of 1 second

And an explanation of the cover diagrams:

For the sake of space, more good explanation here:


OK, one last, and great piece of information on the Golden Record.

Carl Sagan was put in charge of this phenomenal project. Of course, Sagan had a lot of help, including the creative director of the project, Ann Druyan.

"It was a chance to tell something of what life on Earth was like to beings of perhaps 1,000 million years from now," Druyan says. "If that didn't raise goose bumps, then you'd have to be made out of wood."

For Druyan, though, the summer of 1977 and the Voyager project carry a deeply personal meaning, too. It was during the Voyager project that she and Sagan fell in love.

After searching endlessly for a piece of Chinese music to put on the record, Druyan had finally found a 2,500-year-old song called "Flowing Stream." In her excitement, she called Sagan and left a message at his hotel. At that point, Druyan and Sagan had been professional acquaintances and friends, but nothing more. But an hour later, when Sagan called back, something happened. By the end of that call, Druyan and Sagan were engaged to be married.

Ann Druyan and Carl Sagan circa 1977.

"We both hung up the phone, and I just screamed out loud," says Druyan, "It was this great eureka moment. It was like a scientific discovery." The first of the Voyager project's two spacecraft launched on Aug. 20, 1977. Druyan and Sagan announced their engagement two days later. They married in 1981, and were together until Sagan's death in December 1996.

But the evidence of their love has taken on a life of its own. Not long after that serendipitous phone call, Druyan had an idea for the record: They could measure the electrical impulses of a human brain and nervous system, turn it into sound, and put it on the record. Then maybe, 1,000 million years from now, some alien civilization might be able to turn that data back into thoughts.

So, just a few days after she and Sagan declared their love for each other, Druyan went to Bellevue Hospital in New York City and meditated while the sounds of her brain and body were recorded. According to Druyan, part of what she was thinking during that meditation was about "the wonder of love, of being in love."

How awesome is that.

Remember Matt Wilson? He's the dude from the sleep post who hooked up rat brains to neural signal monitors. Matt has gotten so good at decoding the neuronal signatures that he can now just listen to the brainwaves, and without looking at the rats, he knows what they're doing. So yeah, it definitely is possible to interpret actions, and most likely feelings, from firing neurotransmitters. And, awesomely, travelling through space, the sounds of a human body newly in love recorded, that feeling of love recorded, and to be potentially interpreted by some other species a billion years from now, long after we're gone. So fucking cool.


Anyway, there are a bunch of used hardcopies; hardbacks, paperbacks, CD-ROM versions, etc, of The Golden Record books available (see here), and they would, ahem, make a great Christmas gift.



Voyager and its record appear in the episode entitled "Parasites Lost" of the animated television series Futurama. Turanga Leela scrapes the spacecraft off her ship's windshield while stopped at a galactic "truck stop".

In a Saturday Night Live segment, Steve Martin announced that the first message from extraterrestrials was being received. Once decoded, the message stated, "Send more Chuck Berry."

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