Sloan Digital Sky Survey

Swannie writes: "There's a story in today's Chicago Tribune about a joint project that Fermi Lab is taking on with Rensselaer Polytechnic Institute in New York. The goal is to produce a 3D map of the universe using a really big digital camera, and a really creative way to add "depth" to the image. The article has some decent technical details for a newspaper, including a pretty picture." Update: 03/12 15:44 GMT by M : The blurb is in error. A particular scientist from Rensselaer is mentioned in the article, but Rensselaer isn't part of the project as an institution.

Comments

What is a true map?

[phunhippy]

I think it would be really cool if when they take all this data they are collecting, they produced a 3-d image of the COSMOS and a 3-d image of the cosmos with every star's location shifted to show its theoretical place today... or in the case of billion light year stars.... nothing if they are burned out by now.... that woould truly be an intersting map to look at :)

All that Data and no-one to look at it?

[fruey]

So with all the data that few have seen, and few practical business applications, it seems to raise the question as to why are they mapping the universe.

Because it's cool, OK... and because some day the data will be useful, viewable, etc? It will be a map for space travel?

Each tape and a backup copy are sent overnight to Fermilab, where they are transferred to a host of Linux servers. Stoughton said the amount of data is small compared with Fermilab's other projects but is the largest capacity project ever assembled in astronomy.

Cool. They are using the penguin...!

"It's hard to say why people should study astronomy," said Gunn. "But in the scheme of human intellect, it is important to know where we came from and what's likely to be in store for us."

Well, it is interesting to know all about that. But collecting data that can't be used... tough cookie.

In general, these kind of projects get funded by curious people who can't use the data. Loads of data written to disks is not ever looked at, and this article raises that question. This is the discussion which interests me, quite apart from the greatness of some liquid nitrogen cooled super telescope with so many megapixels that at any kind of CRT resolution, for example, we would be decimating 99% of the data in order to get something reasonable to look at.

Re:All that Data and no-one to look at it?

[davecl]

SDSS has been running for quite some time, and has already produced some spectacular results. These include the most distant quasars known, and the largest most homogeneous quasar survey yet (in fact I'm working with some of this data at this very moment).

Whilst much of the data is not eyeballed by a person it is still processed, so there isn't a vast amount of data sitting on disk being ignored. Yes, people can look at the images, but there are too manmy of them and the human eye and mind are too inconsistent to be able to select items of interest in a coherent way. That's why we have computers! Particle physics operates in much the same way - you get a vast number of reactions in an accelarator and only a few of these are of interest, so you use computer-based filters to just select these. In much the same way with the SDSS images, most of them are of blank sky or of stars and galaxies that aren't of interest to the project. They're still cataloged and characterised though, and put into lists to be scanned by later data miners, while the specific goals of SDSS are dealt with at higher priority.

Impossible

[Czarnian]

A true map (100% correct - however see my comment below) cannot be currently made, the science behind the calculations needed to make such a map is uncertain (dark matter, universal expansion speeds, unpredictable effects effects of undiscovered objects - black holes, etc, astrophysics is evolving all the time) and you'd a Beowulf cluster of processors the size of a galaxy to do the math.

In fact, even if we had all the science needed to make the calculations and the equipment to do so, a true map is theoretically impossible, based on the Uncertainty Principle it is impossible to determine with 100% accuracy the state of even an atom, let alone a universe.

Re:Impossible

[Gary Yngve]

Oh, give me a break. The original poster wanted a 3-d map of the universe. By your argument, we don't even have true maps of Earth.

A map with "approximate" positions of the stars/galaxies would be plenty good. Oh no, the sun is off its true center by the diameter of an apple? I am wetting my pants! I can even see the difference of the sun's placement on my super-duper 1e10x1e10 resolution monitor (that provides the ultimate resolution for viewing porn: not only do I see all her parts, I see all the parts of the gonorrhea bacteria that she has).

The real interesting question is how does one navigate [in a user interface] around such a sparse map?

Good application to all that data

[hyrdra]

I can think of a good application for this data.

Why doesn't the SDSS code up a distributed program like SETI to help in the analyzation of all that data to find something unique or unknown. Convert the pictures to 2D FFT's and have a set of known astronomical element FFT's and then do constant comparisons against this set to see if there is anything "unknown". I'm sure it would be more complex than this, but this is how visual image recognition works so I assume it could be tailored for this application.

I would certainly download an run an application that looks for new things in astronomy. I'm sure others would as well. Somehow it's slightly less frivilous than what SETI is doing and we stand to gain more in a quicker amount of time.

That way, when we do actually find something that looks interesting SETI would know where to point that big antenna...

They need our help

[Scorchio]

From the article : "Surprisingly, with all the money and time spent in the quest for a road map of the celestial past, "most of the pictures have never been looked at," Stoughton said. Stoughton said that because of the immense amount of information seeing any part of it would take a lifetime"

What they need is SETI-like distributed software than farms the pictures out to us to look at, and we'd get through them in a week or two. Or stick them all on a website - www.AmIAMinorAstronomicalAnomaly.com - with user rankings. Job done.