Science at Work

We see in the discussion of the left panel yet another example of the scientific method at work. The idea that quasars are nearby objects redshifted because of local velocities is scientific because it is testable. For example, as noted in the left panel, this hypothesis predicts that we should also see quasars with blue shifts.

That we don't observe blue shifts for quasars is then a very strong argument that this hypothesis is scientific (because it makes testable predictions) but is not correct (because the predictions are not verified by the data). Conversely, the cosmological interpretation of quasars appears, based on present data, to be both scientific and correct.