DESI (Dark Energy Spectroscopic Instrument) has just finished measuring redshifts of some 47 million galaxies. That’s Breathtaking !
Analyzed results are expected to start showing up by 2027.
Spectral-Line Redshift shown with Light spectrum Movement
Sadly, these are not real (meaning flawlessly accurate) Redshifts, where the emission spikes and absorption lines move called “Spectral Line Redshift.”
Instead DESI is using a questionable substitute or alternative called Photometric Analysis which only measures colors – not emission or absorption lines. Photometric Analysis’s accuracy is described as “Low to moderate” because it has significant systematic and statistical problems. Primarily is how many independent combinations of galaxy properties, redshift and spectral type (the intrinsic shape of a galaxy’s energy spectrum) can produce identical or indistinguishable broad-band colors.
Well, Drats !
This does not mean DESI’s data is useless. But it does mean that any explanations based on their data being accurate must be independently verified.
