calibration

I spent a great morning at the CfA vising the plate scanning project DASCH. The plate scanner is beautiful, and I saw it in action. I also saw the 100 tons of plates in the plate stacks, and was suitably impressed with the care with which they are maintaining and carrying forward all the meta-data they have. Then they apply some good automatic calibration and are building an archive. I learned from Josh Grindlay that there are enough plates in the Harvard archive alone to have fully imaged the sky 500 times over.

Earlier in the morning I met with Chris Stubbs and discussed many issues related to performing precise calibration of astronomical data sets and providing enough information back to users that the data set will play well with others. We put in some good hours on truly fundamental things such as: What does a telescope really measure? (integrals of the photon phase-space density, in my view) and All precise observations are necessarily relative to astronomical sources with (fundamentally) unknown spectral properties. Stubbs is a deep thinker, and obviously I would say that because he thinks about these things much as I do! Now here's to him taking over the world and bending it to his will.