Sorry - "prone"
Three quarters of the way down the article
Dutch and German boffins have proposed a write-once-read-many storage medium they say should survive for a million years and may be readable after a billion. Described in a paper titled “Towards Gigayear Storage Using a Silicon-Nitride/Tungsten Based Medium”, available here, the five authors explain that in order to store data …
They should build a super powerful laser, point it somewhere into space and modulate it with the desired information. A million years in the future, when faster than light travel has been achieved, they can then skip a million light years to the front of the beam and retrieve all the information.
There is no need to store the information for as long as a million years. We only need to store it until a time-travel receiver has been built: from that point on, people can just go back/forwards to find out what the information was/will be.
Mine's the one with the packet of peanuts in the pocket.
What is the form of the data storage? The article mentions light and electron beams passing through the protective coating. Is it some energy induced phase change of the tungsten structure? Is the data carved onto the tungsten surface and then the protective coating applied afterwards? Because of the picture used in the title, I'll assume that its carvings on the surface, followed by a protective coating.
I'd say that the storage location is much more important that the storage material.
Tungsten is well beloved for its high melting point and that seems to be the relevant property the boffins rave about when they propose etching of information onto tungsten. But if you want to keep stuff for elongated amounts of time, you have to worry about where to store the stuff.
St. Catherine's in the Sinai desert apparently has a good record on the order of millenia, mostly because it was far enough from the rest of civilization and those occasional wars didn't interfere with the storage location. For millions of years you should probably encase the thing in ice and send it on a loong-loong trajectory far away from our sun.
Who knows what kind of data they destroyed when shot that message capsule Tempel 1 .
I agree. Tungsten is too useful. Sounds like a buried bunker on the Moon is the correct place to use.
You can paint the moon's surface with a big arrow telling everyone where the heechee prayer fans can be found. You can also set up a primer to read all the stuff.
It will even be useful for random space explorers who happen to drop by a slightly radioactive ball of slag.
Of course, no matter how good your long term data storage is, it's always prone to the same problem, changing mores.*
Just look a all the medical and engineering data from ancient Egypt, or the astronomical data from the Maya and the Hindi... Oh wait, you can't. Somebody decided that that data was 'improper', and set on it with torch and mallet.**
If you want info to remain longer than it takes for someone to come along and trash it, you're gonna need a lot of copies, stored in secure locations.
Orbital and Lunar repositories, anyone?
*mo·res noun plural \ˈmȯr-ˌāz also -(ˌ)ēz\ : the customs, values, and behaviors that are accepted by a particular group, culture, etc.
** Just a couple of examples. There are many, many more.
Tungsten is is very dense. SG of about 19 to water.
It's also brittle, with a mp of about 3000c. And it vaporizes in air at moderately high temperature.
The materials problems of this concept are not straight forward.
that said keep in mind that CD's were made by physical pits in the disk, so pretty high density is possible. If more subtle effects are available (IIRC it's not magnetic but their are other options) then that could go higher.
For the record, the Thermal Expansion Coefficient is the rate at which a substance expands when it's exposed to heat. Like how a ring might expand when doused in hot water and contract again when doused in cold water.
In terms of material longevity, this means a material with a low TEC (like Tungsten and Silicon Nitride) is unlikely to distort when exposed to heat: A Good Thing.
I wonder if anyone here recalls that tungsten's high melting point was one reason it was was the metal of choice in incandescent light bulbs.
It's neat an all, but I'm struck by one thing about this idea: exactly what kind of machine do they have that can create peaks and pits with the required precision on tungsten? I'm guessing this isn't something that's going to fit into the 5 1/4" bay in your case, nor would I expect it to be very high density by today's standards.
is one of retrieval rather than storage.
If they build a storage medium that will last a million years they also need to build a writer/reader that will last a million years. Otherwise, like reel-to-reel tapes, 8" floppies, and Betamax cassettes, the information might still be there but a functioning device to read it non-existent, since companies see fit to change the media standards every couple of decades or so and planned obsolescence takes care of the rest.
Fat lot of good an archive of these things would be even in 50 years' time, let alone a million, when nobody makes the readers any more...