In a strange coincidence (though perhaps not totally unexpected), I am teaching advanced electromagnetism to a few of our seniors (fourth-year undergraduates) and at the same time, after a long session staring at images from the Project 1640 coronograph, Fergus and I decided that we need to at least discuss and explore the possibility that we might model the electromagnetic fields inside the instrument. That is, we need to figure out if it is possible to model not just the intensity field but the electric and magnetic fields (or, in the steady state, you can think of it as an amplitude and a phase at the detector surface). To my knowledge, except in radio astronomy, this has not been done: Optical (and near-optical) astronomers think of the "thing" in the telescope as being the intensity field (or worse, photons), not the electric and magnetic fields. The challenge is: Superposition really applies only to the electric and magnetic fields, not the intensity field; but at the same time, CCD-like detectors only measure (a noisy sampling of) the intensity field. Saturday night found me starting to write and test some very simple code, with delta-function sources and delta-function pixels.


  1. Today found me less optimistic that this is even possible!

  2. Almost all blogs have new posts on the right, old posts on the left (perhaps reflecting reading left-to-right). Yours is the opposite. Are you left-handed?

    I also prefer the previous/next links above the post so in those rare cases when I don't want to read a post I can jump more quickly to the next one. :-)

  3. I can't figure out how to put "previous/next" links on the posts; it is annoying using these templates!