Digitizing 100 Years of Astronomical Data

Maximum Prophet writes to mention that a collection of glass plates containing astronomical information from the late 19th century through the mid-1980s is being considered for digitization. "The accumulated result weighs heavily on its keepers on Observatory Hill, just up Garden Street from Harvard Square: more than half a million images constituting humanity's only record of a century's worth of sky. 'Besides being 25 percent of the world's total of astronomical photographic plates, this is the only collection that covers both hemispheres,' said Alison Doane, curator of a glass database occupying three floors, two of them subterranean, connected by corkscrew stairs. It weighs 165 tons and contains more than a petabyte of data. The scary thing is that there is no backup." I'm sure that anyone with a spare $5 million or so would be welcomed with open arms.

That's quite a bit.

[L. VeGas]

165 tons of glass plates?

Sounds like a typical lunch clean-up after Rosie O'Donnel.

Sorry. I'm truly sorry.

That's at least...

[TheSHAD0W]

a thousand minibuses full of magtape.

Make it searchable...

[kevlarboots]

... and call it Alta Vista?

Glass plates will outlive the digital"backup"

[gatkinso]

now there is some irony.

Re:Glass plates will outlive the digital"backup"

[WhatHappenedToTanith]

Are you sure about the stability of glass plates? I hear a lot of people have real trouble with windows stability! Sorry, I'll go now....

Luckily glass isn't a liquid....

[Joce640k]

Luckily glass isn't a liquid so they won't distort.

Re:

[ZachMG]

you know we could also ingrain the data into the structure of twinkies and it would withstand a nuclear holacuast, as long as Rosie didnt get to it first.

Re:Luckily glass isn't a liquid....

[ajs]

Glass *is* a liquid (sort of) [wikipedia.org], but it does not flow, which is what I think you were getting at.

Re:

[ajs]

Glass does flow...a look at 80-150 year old windows will show this.

Please follow the link in the post you were replying to, and/or look this up on snopes. This is not true. 80-150 year old glass is simply warped due to less advanced manufacturing techniques, and often thicker at the bottom because window makers tended to place the thicker edge at the bottom.

Re:Glass plates will outlive the digital"backup"

[KokorHekkus]

now there is some irony.

But currently they also makes them vulnerable to a single point of failure (as indirectly pointed out in the article). If you have some data that has any real value for you then having only one copy (or only one storage facility) isn't any real protection whatever method you use. In this case we have data that would be readily accepted for backup by organisations all around the globe and barring a worldwide upheaval the safety of the data would be much better than any single glassplate could offer.

Of course the ideal would be if we could develop a cheap digital permanent storage that had guaranteed physical longevity, say several millenia. That combination would allow easy dissemination of the data and safety by using a multiplicty of sources.

Re:

[bryan1945]

"Of course the ideal would be if we could develop a cheap digital permanent storage that had guaranteed physical longevity, say several millenia"

But would it be compatible with Office 5007 or OO v3452.23?

Re:

[DerekLyons]

Of course the ideal would be if we could develop a cheap digital permanent storage that had guaranteed physical longevity, say several millenia. That combination would allow easy dissemination of the data and safety by using a multiplicty of sources.

Ceramic/fired clay tablets will nicely. There's likely to be density issues however.

Re:Glass plates will outlive the digital"backup"

[seaturnip]

So what? Copy the digital version onto a second set of disks when it comes close to expiring.

Lossless copying means that given a little bit of maintenance, expiration of digital media is a nonissue.

Re:

[Venik]

Ever tried to maintain archival backups for a petabyte-worth of data? You would need a team of operators, millions of dollars worth of storage hardware, expensive climate-controlled facilities. This will not be a one-time expense either. The best way to back up 165 tons of photographic plates is to use more photographic plates to hold microfiche sets. Not exactly cutting-edge technology, but it will outlast any tape archive or storage array. And it will be cheaper.

Re:

[Smauler]

A petabyte is not that impressive any more - It's only a few thousand consumer level hard drives. I do realise that the challenge of managing all that data is far from easy, but claiming that a petabyte requires "millions of dollars worth of storage hardware" is wrong. I just checked on newegg, 500Gb is $110, thus 1Tb is $220, thus 1Pb is $220,000, and this is retail prices. Managing all that crap would be the main problem.

Re:

[sendai2ci]

I don't think they want management as much as equal or better longevity. Some of these plated have lasted over a century, most over 25 years...

How long would a RAID5|ZFS system last? Ten years? At which point you can no longer get spare-parts for the system (well not easily.)

Tape systems would have slightly longer longevity (due to tapes being mainly used for backups.)

Of course cost of storage will go down, so perhaps they could continually upgrade to smaller higher capacity systems, but then it becomes a m

Re:

[FST777]

By that time, other techniques will be available to copy the digital archive over. Heck, it might even be possible to make a copy of the digital data on glass plates, complete with descriptions of the used protocol.

It's true that digitized data is more prone to failure than most analog carriers. The whole point is that digitized data is much easier copied over and over again, without loss, independent from whatever carrier used.

Re:

[Kadin2048]

I think the point is that you'd pay (let's round up for the sake of overhead) $250,000 now, to store a petabyte. Let's also say that the drives are good for five years, at which point you'd need to replace them.

So in five years you go out and buy another petabyte of storage. If we assume that the price of storage halves every 24 months or so, then 1PB should only cost you around $62,500 (again, factoring in some overhead). And five years after that, maybe $16k.

The "halves every 24 months" argument could be

Re:

[Venik]

And where would you put your 2000 hard drives? Your VCR? What if - however surprising this may seem to you - one of your 2000 hard drives fails? Would you tell the customer that you just lost 500Gb-worth of photos and three years of their research data? What if you lose two hard drives? We all store a great deal of porn on our PCs, but this is not the same.

Re:

[Venik]

The final price depends entirely on what equipment and methods you chose, and, therefor, what level of reliability you can expect. Don't look at the price of just the hard drives: you still need something to put them into. Look at the prices of high-end disk arrays capable of storing and managing 1Pb of data with adequate redundancy, expansion capability, and enough space left over to refresh data every so often.

Add the cost of a workgroup- or enterprise-level Unix server to handle data integrity maintenanc

Re:

[profplump]

And your photographic copy would A) degrade over time and B) lose quality with each copy. IMHO that's not a very good archive. Moreover, in order to slow the inevitable decay that comes with time and reactive chemicals on paper/plastic/metal/whatever, you'd still need a climate-controlled facility. And you'd still need a team of operators to make the copy, and to make later copies as the earlier ones degrade. And more than anything else, you'd need someplace to store *another* 165 tons of photos, which is c

Re:

[Venik]

Photographic copies have a few advantages over digital data storage media. Photographic plates, properly stored, will reliably last 20-30 years, at least. Tapes and hard drives will not. Digital data will need to be maintained. Storing such a large amount of digital data will be a continuous process of reading and writing; replacing disks, drives or tapes; upgrading software, hardware and networking. This is not the kind of a backup that you will be able to put away for 20 years and then go back and "refres

Re:Glass plates will outlive the digital"backup"

[Cecil]

Ever tried to maintain archival backups for a petabyte-worth of data?

Yes, as a matter of fact. Definitely a lot of work is involved, but do you believe that you wouldn't need a team of document managers, millions of dollars worth of floor space, and expensive climate controlled facilities for archival of microfiche? You most certainly do. It's a lot of data. Period. No matter what you try to do with it, it's a lot of data. It's going to require a lot of resources. That's just a fact of life.

Anyway, noone in their right mind would choose microfiche for that type of data. If you're only storing plain text pages it's adequate (though I still don't think it would be the "right way to do it" in this day and age), but for photographic plates? Not going to work.

Microfiche is vastly overrated, in my opinion. My current project involves taking 2 floors worth of 30-50 year old microfiche and scanning it, OCRing it, and PDFing it. Yes it certainly does age. Quite poorly, in fact. The quality is absolutely terrible compared to the paper versions, some of it is stuck together, and indexing and cataloging it is a nightmare all of its own.

Yes, there are challenges in the digital world too, but most are easily surmountable given a little bit of common sense in understanding that digital is not magic. It doesn't mean you can "fire and forget". The documents will still require maintenance, cataloging, protection and monitoring. Format obsolescence is very nearly a nonissue, it is blown way out of proportion. That's where the "maintenance" comes in. The key benefit of digital is that you can and should losslessly upgrade your format whenever obsolescence is becoming a concern. Formats do not disappear overnight and suddenly everyone forgets what to do with them, you have plenty of time to make your transition if you're paying attention (which you must be: again, digital is not magic).

Re:

[Venik]

I think this digital optimism stems from the fact that very few people tried to access any large body of 50-year-old digital data. I know that in the aerospace industry in the US average retention of backups rarely exceeds five years. This is because reliably storing data for longer periods of time causes the costs of backup environment to skyrocket. Sometimes I had to deal with recovering data from 10-15 years ago with mixed success. I remember one instance when data could be recovered from tapes but lucki

Re:

[Cecil]

I don't think you understand... you're not supposed to ever let them sit that long. That's my whole point. Maintenance, maintenance, maintenance. You can't just drop your "backups" into a vault and go "ahhh, now they are safe for eternity, because they are digital". It's not magic.

Re:

[Venik]

This is exactly my point. I think you meant to reply to someone else's posting.

Microfiche is terrible, short life span

[fantomas]

Microfiche has a short life span. When I was working at the Royal Greenwich Observatory they'd done some research and discounted that as a feasible option. Something like 25 years if you're lucky? The glass plates in the RGO were from the same period as these American ones, and in equally reasonable condition (in most cases.... the problem was there as well... we were transferring them to acid free paper sleeves).

Re:

[Venik]

If your glass plate with microfiche reliably lasts for 20 years, this will be about 10 years more than I would give any hard drive or tape. It amazes me how willing people are to believe in the longevity of digital data. This supposed longevity is largely an urban myth. Banks, universities, insurance companies keep lots of data in digital format for extended periods of time. But it costs them a pretty penny and almost invariably they still maintain paper archives.

Re:

[jon287]

Hey now...

People who curate glass museums shouldn't throw stones!

I can't wait to see...

[Quaoar]

...all the alien porn I've been missing!

Re:

[networkBoy]

So why not sig your all important link?

Re:

[ScrewMaster]

Google might do it just because it would be un-evil, and worth quite a few brownie points with scientists around the globe, not to mention that it would be cool archive to search.

Re:Would Google archive it, perhaps?

[networkBoy]

Google Universe (beta)
Searchable in Lat/Lon/time/intensity
that would be awesome...

data/mass ratio

[tenco]

That's about 6e6 Bytes per gram. Digitizing that data means lots of redundancy while preserving the total mass of this collection.

Re:data/mass ratio

[HappyEngineer]

It depends on the number of pounds in a ton, but if it's short tons then

165 short tons = 149,685,482 grams
1e15 / 149,685,482 = 6,680,674 bytes per gram

A quick check of amazon turns up a 1TB drive which weights 2.4 pounds.
That's 1,089 grams which is 918,592,757 bytes per gram.

Unless I've messed up my math, it looks like hard drives store 137 times more information per gram. That's not as large a multiple as I had imagined though. The whole thing should still be between 1 and 2 tons when put on hard drives.

Re:

[LeadSongDog]

Factor in Kryder's law http://en.wikipedia.org/wiki/Mark_Kryder [wikipedia.org] and the rate of scanning will decide the peak storage mass.

This sounds like a job for Google

[MDMurphy]

Google provides views of the Earth, Moon and Mars, why not stars? If the information was made available for them to deliver to their users, they might be interested.

Re:

[CanSpice]

Don't worry, it's coming. I've seen previews of Google Sky at a couple of astronomical conferences so far. Also, check out partner number four for the Large Synoptic Survey Telescope [lsst.org].

Re:

[TheSciBoy]

What a lousy internship that'll be.

"Yeah. Mmmm. I'm going to have to have you do this job for me; it's digitizing this 165 tons of astronomical photographs on glass plates. Mmm. It would be good if you're done before the summer is over. That's great. Mmmm. Thanks."

A Million People With $5

[Stranger4U]

This seems like a great opportunity for either corporate sponsorship, or a grass-roots donation drive. In all honesty, $5 million isn't a whole lot of money for the likes of any real corporation, and it probably wouldn't be that hard to raise it through small donations from individuals. Espectially if you could ascribe names to some or all of it. How would it feel to be able to personally identify which plates you paid to have scanned? (this image of the Crab Nebula brought to you by John Smith) I'm surprised Paul Allen or Richard Branson aren't all over this like stink on shit.

Re:

[denidoom]

I was thinking of Branson too. Someone will come up with the dough.

Google

[blhack]

I'm sure that a company like google would be MORE than willing to fund a project archiving these. The positive press, proliferation of their intended "do no evil/good guy/just another bunch of geeks" image, having their name on a major scientific project would easily be worth the investment.

Re:

[dpilot]

I'm sure Microsoft has a way to store this data, no doubt with an "open" format. Things like this are too important to trust to anyone but Microsoft!

Backup?

[Anonymous Coward]

Of course, as long as they can keep mildew at bay, odds are that the plates will long outlast any digital record. Of course it always makes sense to keep a backup, not to mention the value of an instantly-retrievable library.

Re:

[TheSHAD0W]

How about we make a backup of the backup on glass plates...

Ack! Put down that knife!

This is a job

[JohnnyGTO]

for Google. Man if I had a spare 5 million I'd be all over that, I love data.

InfiniBytes

[Doc Ruby]

contains more than a petabyte of data

Glass photographic plates, especially from silver emulsion, are analog at extremely fine granularity. Effectively molecular, depending on how flat the glass surface was settled from its molten liquid state. The features of its silver oxide crystals, laid in place by individual photons arriving from vastly distant stars, could be meaningful at less than a nanometer. Especially when measuring extremely subtle influences, like the gravity from one distant star bending the light of another distant star, measured across a century in which those stars lost gravitational mass, for comparison.

There is a practically infinite amount of data on each of those plates, limited by our precision in measuring them. It's a smaller degree of infinity than that of the sky. But the original infinite sky is lost. While the plates' lesser infinities are impossible to replace, and all we'll get to use to look back across all the billions of years we saw in a long century of them.

Re:InfiniBytes

[modecx]

here is a practically infinite amount of data on each of those plates, limited by our precision in measuring them.

And limited by the lenses/mirrors, and limited by atmospheric effects, and inconsistencies in the glass, and the silver, and, and....

I can't testify to the quality of the glass negatives, but I can testify to the fact that as much as people like to believe, even the best modern analog capture sources aren't anywhere near practically infinite, even in the best laboratory conditions.

Re:

[Doc Ruby]

Well, the lenses/mirrors that are now lost to history do introduce noise. But the atmospheric effects, and inconsistencies in the glass and silver, and probably much of the "writing" noise from the optics do all hold the possibility of being filtered out. Maybe not now, with today's early signal processing tech. But in another hundred or more years, that signal info could be available. If we don't damage them in the interim.

Re:

[Smauler]

You're ignoring noise, and noise is a huge factor with analogue (and digital) readings. Many people in the past have ascribed meaning to analogue readings that were not there. At the nanometer level, especially, I think it's almost bound to all noise with most applications.

Saying that "The features of silver oxide crystals [...] could be meaningful at less than a nanometer" is not actually saying anything. If they are meaningful, say they are. If there is evidence of them becoming meaningful, reference

Re:

[monopole]

Having worked with holographic media for decades (which is about as fine resolution as you can get optically) the maximum resolution is on par with the grain size 40 nm (Afga 8e75) and considerably worse both due to the wavelength of light and the expansion of grains during exposure. To get 'molecular' resolution you'd have to go over to dichromate plates far too slow.

Due to speed considerations the grain of these plates would be much worse. But well within the resolution of the 'scope used for recording.

Al

Re:

[Teancum]

The article does mention that this staff tried to mark a compromise between scanning so finely that they would record noise (a problem when doing analog to digital conversion in any format, but especially image data) and not well enough that you also lose data.

You can debate the choice here in terms of where to draw this line, and to suggest that they use some archival quality file format that does lossless image compression, but this is something that did go into their consideration.

I'm so glad that they h

Re:

[djmink]

We are preserving all of the raw scans, and the plates will be preserved, too. Our scans resolve the photographic grains, going well beyond the actual resolution of objects in the sky. We are also saving a few more bits of intensity than are
found in the photographs. This is a pretty good time to be creating this archive, not just because the scanning technology is mature and storage technology is tracking our needs. There is also a greater interest in the astrophysics of temporal variations in anticipat

Re:

[Teancum]

We are preserving all of the raw scans, and the plates will be preserved, too. Our scans resolve the photographic grains, going well beyond the actual resolution of objects in the sky. We are also saving a few more bits of intensity than are
found in the photographs. This is a pretty good time to be creating this archive, not just because the scanning technology is mature and storage technology is tracking our needs. There is also a greater interest in the astrophysics of temporal variations in anticipation

Re:

[Doc Ruby]

The optics can be subtracted from the recording if their specific details are known. That's the beauty of analog recording: it is infinite.

And when the sampled phenomenon is as vast as all of interstellar space, that infinitude is relevant.

Re:

[sholden]

It's obviously not infinite. There is some number of atoms involved in the image, and they can only take on a finite number of states and still be an image on a plate. Plus of course the pigeon hole principle should make it pretty obvious that the image on the plate can't represent all possible configurations of the atoms in the part of the universe it took an image of (since there are more of them then there are possible configurations of the plate) and hence not everything has been recorded and hence it's

Re:

[Doc Ruby]

I said "practically infinite". That's because the data is not limited by the storage medium, but by our limited ability to read it.

It's funny how many people jumped on me for my pointing out how much more than a "petabyte" is on those plates. But no one has joined me in laughing at the "petabytes" claim.

Slashdot is retarded.

Re:

[sholden]

Please point out the word practically in: "The optics can be subtracted from the recording if their specific details are known. That's the beauty of analog recording: it is infinite" cause I sure can't see it.

Maybe if you didn't make completely ridiculous claims people would join in with you laughing at other people making less ridiculous claims? The claimer in question, curator of the collection and hence possibly knows a little about it - though less about computing and digital versus analog, is certainly

Re:

[Bugmaster]

Ok, let's say that we've managed to get the original optics. We've discovered that, due to slight focusing error (which is fixed) and atmospheric effects (which are chaotic), each point on the photographic plate was blurred by 0.01 mm. How do you recover the "infinite" precision from this data ?

Re:

[Doc Ruby]

"Blurred" is an oversimplification. What we could get from the original optics is the convolution by what optics signal the recorded signal was changed. So we could deconvolve the data on the plates. In a hundred years, I expect our skills at such deconvolution of optics at the nanoscale will be quite good. We held those plates for a century, we ought to hold them for at least another to get the full use of them.

Re:

[Doc Ruby]

In another hundred years that kind of data collection will probably be easy. But still extremely valuable, because the data recorded in them is irreplaceable.

If the astronomers who recorded these plates weren't anal, then astronomy wouldn't be advanced enough by now for you to enjoy it as an amateur.

sounds familar

[Anonymous Coward]

anyone with a spare $5 million or so would be welcomed with open arms

That's what she said!

Planets et al...?

[BigBadBus]

Maybe we'll get some data on possibly extra solarplanets from this?

All this stuff should be digitized and made public

[syousef]

When I completed my Astronomy masters access to publicly available data from various sources (most notably NASA data made free to the public) was a real boon. It meant we could do analysis on actual real data instead of artificial or sanitized textbook material. A couple of the students built on this to do some original research. (Sadly that's not the way I went, as my time was more limited).

There are also lots of amateurs out there running a wide variety of very specialized packages to do everything from discovering asteroids to keeping tabs on the brightness of stars and watching for supernovae.

Re:All this stuff should be digitized and made pub

[dargaud]

Two years ago I worked in a place [gdargaud.net] doing some preliminary astronomy experiments previous to going BIG. I was doing atmosphere science. During a chat with the resident astronomer, I asked where their data was publicly available. His answer, in short: "absolutely not, it's our funding, so it's our data. We release only the final paper. We don't want competition from other labs/astronomers."

That answer astounded me as in our own project the point was to make the data public as efficiently as possible. I mean,

Re:

[faxafloi]

...but I've searched high-res sky images in the past without finding anything systematic except some specific projects such the Sloan Sky survey (which are just coordinates) or the odd marketing Hubble shot.

If that's all you found, you didn't look hard enough. Sloan serves imaging and spectral data, and all of Hubble's science data (for example) has been available from three different data centers since 1992. (This is data we're talking about, not pretty pictures.) In fact, all NASA-funded missions are re

Re:

[syousef]

If you were a professional astronomer I'd say it sounds like you'd be better off finding a different organization to work for.

Try looking at cited sources on published papers for starters. http://arxiv.org/ [arxiv.org] will give you plenty of pre-publications. Here too http://sesame.stsci.edu/library.html [stsci.edu]

I'm well out of touch but here's what you get just from Google:

Skyview is a must. Images in any wavelength (multiple instruments)
http://skyview.gsfc.nasa.gov/ [nasa.gov]

Learn about the FITS data format. Not just pretty pictures b

Harvard can handle the burden

[tchdab1]

From here: http://www.hno.harvard.edu/guide/finance/index.htm l [harvard.edu],

This:
Harvard University's endowment, valued at $25.9 billion at the end of FY 2005, is a collection of more than 10,800 separate funds established over the years to provide scholarships; to maintain libraries, museums, and other collections; to support teaching and research activities; and to provide ongoing support for a wide variety of other activities. The great majority of these funds carry some type of restriction.

I think they can scare up the change.

Re:

[Anonymous Coward]

Absolutely correct. According to records, Harvard saw their endowment fund appreciate over 16% in a single year (FY2005). Sixteen percent of $30 billion is nearly $5 billion which would allow them to quite easily fund this project. Even if Harvard has the fund invested in an interest-bearing account at 5%, they're still seeing around $1.5 billion per year in interest income - something more than $4 million per day. This project is chump change.

Re:

[moosesocks]

They might, but I doubt it. Unless they could potentially turn it into a media blitz, I genuinely doubt that Harvard (or any private institution for that matter) would pick up this sort of project.

If they did, they'd keep it private, and only share it amongst other institutions "prestigious" enough to be deserving of the blood and sweat of Harvard scientists.

I'm sorry, but the Ivy League has quickly degenerated into a billionaire's playground. If they turn away thousands of "perfectly qualified" applicant

Re:

[drwho]

The reason why Harvard HAS so much money is because they don't SPEND it. Kind of like that crazy uncle Joe you have (or wish you had), the one that drove a school bus for his whole adult life and died with an estate worth over a million dollars. Yeah, Harvard is weird like that. I should know. I am depending on a NSF grant for my salary at Harvard, the school doesn't seem to want to give me any of its money. However, they seem to fund all sorts of useless "humanities" programs (I am not saying that all huma

A great idea.

[niktemadur]

If they manage to standarize a century of these plates, it would significantly extend the time range of data to digitally extrapolate and detect objects previously missed. Just to speak of mapping our own cosmic backyard, a significant amount of slow moving, previously undetected Kuiper Belt Objects, for example, would more easily pop into view. Surely a bunch of comets, too.

Clyde Tombaugh captured Pluto several times during his three decades long hunt for the elusive Planet X, but failed to put the pieces together. If he had had digital technology, he would have shaved off at least a decade of effort. So imagine all the extremely useful raw data still stored in those plates.

Re:

[dwarmstr]

Uh... Tombaugh was 24 when he discovered Pluto aka Planet X. He later searched for other objects on the ecliptic, is that what you mean?

Re:

[niktemadur]

Right! Let me set the record straight:

1. Pluto had been captured on plate as far back as 1915 by another astronomer, and it was he that missed it, not Tombaugh. So if they had known what they were looking at back then, the search would have been shortened by a decade and a half.
2. Tombaugh kept on searching for other candidates for Planet X after discovering Pluto.

An interesting tidbit is that during the 1930's, the only 24 hour radio station whose signal reached Flagstaff transmitted from Ciudad Juarez i

165 tons? My God

[fredrated]

that's astronomical!

More than just a flat scan

[CraterGlass]

There is more to this than simply scanning a flat image. The emulsion on these plates is a three dimensional medium, and different data can be extracted depending on your focal depth into the the emulsion. I believe David Malin did much pioneering work on this kind of thing, including the use of different layers for unsharp masking.

There will be information in the plates that is not yet part of human knowledge, and a simple scan of one focal plane is not going to get it all.

Certainly it is worth taking backup images of these plates in any way we know how, but we should remain aware that, as of today, no technology exists that will make exact duplicates of them, so great care should always be taken to preserve the originals.

Re:

[Richthofen80]

no technology exists that will make exact duplicates of them

Well, I mean, there is no technology that exists to make an exact duplicate of ANYTHING. That doesn't mean that digitizing this information is useless, however.

You mention that these are three dimensional mediums. Fine, three-dimensional data capture is nothing new. You're right, plopping this thing on a scanner is not going to work. But I'm sure that in some way we can get an image at a set of depth intervals and save those. Now there is an additi

GoogleSky

[12357bd]

Seriously, let Google index not only that collection, but any stellar image information and launch GoogleSky.

Solution: Roaming "Scanner" Trucks

[weinrich]

Step 1: Ask 15 to 20 major companies to each sponsor a "scanning trailer". They'd get their name and logo all over it and be part of the on-going story and never-ending literature, etc.
Step 2: Build-out a tractor trailer per sponsor to include everything needed to do scanning of archived materials (books, papers, photos, glass photo plates, etc.). Power source, scanners (many per trailer), etc.
Step 3: Drive the swarm of scanning trucks to the parking lots of an archive in need of backup.
Step 4: Connec

PETA-byte???

[Muad'Dave]

...contains more than a petabyte of data.

You can be sure that all those PETA-bytes [peta.org] are vegetarian!

Crunching the numbers

[Muad'Dave]

If we assume there are a half million plates as the article states (let's call it a 512K, i.e. 2^19), and there's a petabyte (2^50) worth of uncompressed data on them, that's 2^31 bytes (2GB) per plate. Assuming 3 bytes/pixel and square plates, that's about 26750x26750 pixels. With a 12x12 inch plate, that'd be about 2230 pixels/inch. If the plates are smaller, say 4 inches, that goes up to a more respectable 6700 pixels/inch.

Cost of storage? Free!!! They should get a few gmail accounts and store the sca

Both hemispheres?

[faxafloi]

Not sure what's meant exactly by it being the "only collection to cover both hemispheres". The Digitized Sky Survey [stsci.edu] covers the whole sky and it's been online [stsci.edu] for 12 years.

Re:

[bmk67]

It's the only collection of photographic plates that covers both hemispheres. Despite DSS, this data is extremely important to astronomical research.

Re:

[faxafloi]

The DSS is a collection of plates that covers both hemispheres.

Re:

[bmk67]

You are correct... I didn't check the link you provided and assumed you were talking about the Sloane DSS (which uses neither photographic plates nor is full-sky).

Funding, complexity, ownership

[drwho]

I don't think it would be hard to find some company to pay $5m, if they could keep the rights to the images, and pull a Westlaw type of scam. I am sure Harvard-Smithsonian isn't going to fall for this. They want to keep these images for the public, which makes it difficult for anyone to build a business model on and therefore difficult to get funding for. How would Google make money on this? Google adwords for a particular star? Or perhaps on google maps - "coffee near Barnard's star"? I am not saying that

Re:Why does it have to cost so much?

[JohnnyGTO]

Those plates as well as being old and delicate contain a LOT more information then a piece of paper. Considering that something less then 1/4 the size of the period on the end of the sentence is important your scanning at a much higher resolution.

Re:Why does it have to cost so much?

[ghostlibrary]

> I spearheaded a "digital backup" of around 90 filing cabinets of papers ...
> It took 2 years and way WAY WAY less than $5,000,000 to do it

500,000 plates. Over 2 years, assuming 50 wks/yr means just 5000 plates need be scanned per week. 1000 plates per day. 125 plates per hour. And this is large, fragile glass with really high data density, so you have to be a) careful in handling and b) use slow high-res scanning.

Let's take a guess that it takes only 10 minutes per plate (to fetch, tag, load, scan, and return). So we need only 20 people to scan 125 plates/hour.

Well, assume 20 scanning people and 1 IT guy handling the sysadmin work for the petabyte storage. Also one scientist/manager. Take a low intern/grad student $35k, 1 sysadmin at $65k, 1 PM/sci at $85K. All x2.5 for overhead, for 2 years. That's $4.25 mil in salaries.

There's also buying a redundant petabyte and all the necessary gear. I'm amazed they figure $5mil can do it.

Re:

[mikael]

The storage hardware wouldn't need to be stored onsite - all they would need is a high-speed data connection through a fibre-optic link wired up to the optical scanner. For redundancy, you would want the digital backup stored somewhere else
as well as onsite.

Re:

[simong]

In fact, they should put them in Picasa and let Google store them.

>>coat.

Re:

[going_the_2Rpi_way]

Well, they could work on a cost-recovery basis at first, and prioritize 'client' files on demand, adding them to the master DB as they go. If two or more universities want the same palte or same series of plates, they can form an alliance to split the cost. That way, high demand or high interest plates are scanned first, and losses are minimized. That's not unlike what they've done for GIS datasets in many places for instance, and governments are often the largest single client so far as I know.

Re:

[geekoid]

haha, man, I run into people like you and wonder "Have people always been unable to think."

You are comparing 90 filing cabnets of paper to this.
The fact that A the paper isn't at all the fragile B it's not nearly as much data, 3 that they need special scanners? The they would need at least 5 people to do this? Probable 9 since you are going to want to have people whose only job it is to move the plates.

I wonder what you thin the true cost of the work you mentioned was?
I would guess it at about 200K, for you

Re:

[hey!]

In addition to the other points made, remember that the plates are fundamentally analog. Last year's memos, even if they are typewritten, are discrete. A smudge that makes a letter hard to read hardly matters, but it could be the one item you are looking for on the plates, irretrievably lost.

Re:

[geekyMD]

Holy crap dude, you just won the asshat of the year prize. Do you have any idea of the magnitude, delicacy, or importance of the data you're talking about? To say nothing of the needed precision when scanning.

"I scanzord 90 filing cabinets of paper into teh computerz"

You know what, I used to launch model rockets. Its really easy to make stuff go up. Just buy the kit, attach a little engine and off it goes. $30 easy! Freakin NASA I bet they're spending all of our tax dollars on pr0n.

"cheapish 20megapixe

Re:

[Chief Camel Breeder]

You need specialized scanning machines for astronomy. Office equipment doesn't do the job.

• The plates have to be scanned in transmission, not reflection (they are photographic negatives).
• You have to accurately measure the darkness of the plate in order to deduce the light intensity that fell on it. Office scanners only approximately measure the light and dark - enough for visual presentation, not enough to do maths with the result.

My colleagues in the UK had such a scanner. It was ~7 tonnes of metal, gl

Re:

[Anonymous Coward]

You only saved $5 million? Are you on dialup or something?