4 ms·
Totally! All these ideas are just a placeholder to make a note of something we can observe until we have a better theory. Luminiferous aether was invoked to e
by devoutsalsa 2y ago
Totally! All these ideas are just a placeholder to make a note of something we can observe until we have a better theory.
Luminiferous aether was invoked to explain the ability of the apparently wave-based light to propagate through empty space. [1] Eventually we found evidence that contradicted that idea.
Dark matter is implied by gravitational effects which cannot be explained by general relativity unless more matter is present than can be observed. [2] We are searching for direct evidence, but haven’t found any yet.
[1] https://en.wikipedia.org/wiki/Luminiferous_aether https://en.wikipedia.org/wiki/Luminiferous_aether
[2] https://en.wikipedia.org/wiki/Dark_matter https://en.wikipedia.org/wiki/Dark_matter
- the__alchemist 2y agoThis applies here too: See my comment above; most cosmologists are confident (And/or focus most work on) Cold Dark Matter, e.g. in an ellipsoidal halo around galaxies. I am not making a qualitative judgement, but dark matter is not used in cosmology papers as a placeholder.
- danparsonson 2y agoIt's a placeholder in the sense that we don't know specifically what it is though, right? No cosmologist uses "matter" when they mean "protons" for example.
- the__alchemist 2y agoYes; it's still reasonably broad. (MACHOs? WIMPs?) But this is still, in terms of all possible explanations for observations re rotation curves, and the Bullet Cluster etc, well defined. It includes a lot of possibilities, but also excludes.
- uoaei 2y agoUnreasonably narrow, rather! We have not convinced anyone, much less done the proper science, to stick to our guns so long that it is truly matter we are hunting to explain this phenomenon.
- elashri 2y ago> No cosmologist uses "matter" when they mean "protons" for example. They will call that "baryonic matter".
- danparsonson 2y agoNo, they'd call them protons; baryons are a class of particles, of which protons are a member.
- elashri 2y agoThis is what a particle physicist use the term for. But for cosmologist on the question of matter composition they will use the term in different way. I was replying to exactly the quote from your reply.
- uoaei 2y agoThe point is, it's already a theory to even suggest it's "matter" and not any other explanation.
- devoutsalsa 2y agoIt certainly doesn't matter yet. I'll see myself out.
- floxy 2y ago>No cosmologist uses "matter" when they mean "protons" for example. Don't astronomers call elements like neon metals? Maybe cosmologists don't? https://en.wikipedia.org/wiki/Metallicity https://en.wikipedia.org/wiki/Metallicity