I Any direct measure of Universe expansion via galaxy subtended angles?

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The discussion centers on the possibility of directly measuring the universe's expansion by observing changes in the subtended angles of galaxies over time. While some participants question the validity of the Doppler interpretation of redshift, others assert that angular size distance measurements are already a key method in cosmology. The consensus suggests that the predicted changes in galaxy size are too small to be detected within a 5- to 20-year timeframe, given current technological limitations. Additionally, it is emphasized that galaxies do not expand in the same manner as the universe itself, as gravitationally bound objects remain stable. Overall, the conversation highlights the complexity of measuring cosmic expansion and the need for precise observational techniques.
  • #61
dabunting said:
If we're not questioning, we're not scientists.

Questioning things that are still open questions is indeed part of science.

Questioning things that are nailed down by data is not.

dabunting said:
There's a lot we don't know about the universe

But there's also a lot we do know, and you can't usefully speculate about what we don't know until you have a firm, thorough grasp of what we do know. The rest of your post is speculation without such a firm grasp, and such speculation is not allowed per the PF rules.
 

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