Padmanabhan (Princeton), Blanton, Weiner, Masjedi, and I discussed transparency (again). It really seems to me that this is fundamental and observably constrainable, whatever the theories predict; of course Padmanabhan and Weiner think we should rule out specific models, but I am happy to say what we can, but say it in such a way that it will rule out future models, even those not yet worked-out.
We found five clear and possible tests: Average spectrum of old galaxies as a function of redshift (most non-trasparent models predict wavelength-dependent changes that are not attributable to age or chemical composition), average spectrum of galaxies as a function of angle at the same redshift (most models have anisotropies in absorption/conversion of photons), average spectrum of galaxies as a function of foreground structure (most models have absorption/conversion depend on line-of-sight details), angular size of high redshift sources (most models blur point sources at high redshift), and the Tolman test (described earlier). The first three are trivial with SDSS data, the fourth is trivial in the literature and/or with HST imaging of quasars, and the fifth will be possible in the next five years or so.
Golding (Princeton) gave a nice talk on measuring rates and variability for RNA transcription and protein translation in individual cells, opening up the possibility of a future in which cell properties and variability are understood in terms of, say, differential equations.
Willman, Wu, and I discussed the Virgo Cluster project, in which Wu is connecting SDSS observations to the traditional Binggeli et al Virgo Catalog and thereby critiquing both the SDSS and the Virgo Catalog. It is a pretty complex data project, because the Catalog is large enough that it is hard to do things by hand, but small enough that we don't want to permit any errors, even on troublesome entries.
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