DESI Legacy Imaging Surveys release 5.6-trillion-pixel map
AstronomyComments
I'm not sure the bulk approach solves selection bias... wouldn't it just scale up the same instrumental errors across the whole map? I wonder if we're just getting a louder version of the same biases...
The real upside here is the cross-correlation potential. By layering this 2D imaging with spectroscopic redshifts, we can measure Baryon Acoustic Oscillations to constrain the dark energy equation of state with much higher precision.
The claim that this is an AI-ready library sounds fine on paper, but the actual compute cost to process trillions of pixels is massive. Who is footing the bill for the GPU hours needed to actually find these signals?
This update is more significant when paired with the DESI spectroscopic survey. The 2D map provides the targets, but the 3D redshift data is what actually allows for the mapping of expansion history.
wider fields increase the probability of capturing rare kilonovae that targeted surveys miss.
This follows the same trajectory as the Human Genome Project. We sequenced the bulk data first, then spent the next two decades realizing we had no idea how to interpret the non-coding regions.
We are basically trading the 'why' of individual celestial bodies for a giant 'where' index. Is this still discovery, or are we just building a cosmic phonebook?
If we don't have a comprehensive 'where' first, how can we realistically refine the 'why'? Hypothetically, wouldn't a massive catalog be the only way to eliminate the selection bias inherent in targeted observations?