Archive | April 2013

A New Name, Debugging, and Some Mind Games

Spring is here, or at least coming along, and the Lens Zoo development tiger team is emerging from its incubator. Since just before Christmas we have been hard at work pulling together the many different pieces needed to make a Lens Zoo work well. This week, the Science Team is helping debug the identification interface that the Dev Team built, and then we’ll be ready to beta test it. It’s looking very cool. Following discussions here and elsewhere, we settled on the project name “Space Warps.” As Thomas J pointed out, with this name we won’t ever have to explain who “Len” is!

While all that is happening, we are also starting to think about how the other parts of the project might work. Once our spotters have identified an initial batch of lens candidates, we will have to figure out what to do with them all (and they will be numerous!). A good first check is to phone a friend: with the Talk system, we’ll be able to assemble collections of lens candidates for everyone to comment on. You can see this happening already, freestyle, in Galaxy Zoo Talk. We’ll be trying to come up with ways of making it easier to browse collections in Talk, and to be able to cast your vote on whether you think each object is a lens, or not.

But hang on: isn’t voting rather subjective? Well, yes and no. A key part of the lens-finding process is modeling, that is, figuring out whether the features we see in the image could actually be due to gravitational lensing. A minimum requirement for a successful lens candidate is that its images be explained by a plausible lens model! Fortunately, some initial lens modeling can be done mentally: this is why much of the site development effort so far has gone into the training material needed to help people understand what gravitational lenses look like, and how the arcs and multiple images are formed. Think about what you are doing when you make a judgement about a lens candidate: you are imagining how that image could have been formed, and to do that, you need a model of a gravitational lens in your head!

For the more difficult and ambiguous cases though, we’ll need to actually make some predicted images, using a computer model – so we’re thinking of other ways that we could enable this. Several members of the Science Team have written lens modeling software, we just need to make it possible for all of you to use it! More on this soon.