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Comment by handsclean | Hacker News Reader

It’s not just phlogiston, it’s the lifecycle of all scientific theories that they’re used for as long as they make accurate predictions, then we start seeing things they mis-predict, then they’re revised or replaced. You seem to think the expanding universe theory can still be saved by some data artifact or parameter tweaking, but that’s been hunted for years and we’re still at “we just can’t make it match everything we’re seeing”. Historically, that’s what precedes significant revision or replacement.

> Redshift is not the only observation we have.

What else is there?

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> it’s the lifecycle of all scientific theories that they’re used for as long as they make accurate predictions, then we start seeing things they mis-predict, then they’re revised or replaced.

No, that's not what always happens with scientific theories. For example, Newtonian mechanics is still used, even though we now know it's not exactly correct; it's an approximation to relativity that works reasonably well for weak gravitational fields and relative speeds that are small compared to the speed of light.

The "mechanics" that Newtonian theory (and its predecessors, Galilean mechanics and Kepler's model of the solar system) replaced were indeed replaced--nobody uses Aristotelian physics or Ptolemaic cosmology any more, not even as approximations. But that does not always happen.

> The "mechanics" that Newtonian theory (and its predecessors, Galilean mechanics and Kepler's model of the solar system) replaced were indeed replaced--nobody uses Aristotelian physics or Ptolemaic cosmology any more, not even as approximations. But that does not always happen.

Yeah, about that... A not-insignificant number of people would have a hard time explaining why the moon has phases, let alone be able to do something like explain the sidereal day.

Galileo’s principle of relativity is used all the time.

>> What else is there?

The relatively CMB, which points to a past when the universe was more homogenous than it could/should be given SoL limitations on communication between distant locations. The only answer is that those locations were at some point in the past much closer together.

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