I don't know if any of you saw the press release earlier this week, but HST made a direct-ish measurement of dark matter. "Direct-ish" because they looked at a galaxy cluster and measured how light from background objects was distorted by the cluster's gravity. In the end, the mass distribution required for the gravitational lensing formed a big ring far from where the luminous matter in the cluster was actually located.
My personal take on things follows after the jump.
Continue reading A rant about dark matter