Editing Talk:1758: Astrophysics

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And here we go again. [[Special:Contributions/198.41.239.32|198.41.239.32]] 23:46, 11 November 2016 (UTC)
 
And here we go again. [[Special:Contributions/198.41.239.32|198.41.239.32]] 23:46, 11 November 2016 (UTC)
 
:But this was the same way that led us to discover Neptune, Uranus, Pluto, and the Kuiper belt. [[User:Theme|Theme]] ([[User talk:Theme|talk]]) 06:49, 12 November 2016 (UTC)
 
:But this was the same way that led us to discover Neptune, Uranus, Pluto, and the Kuiper belt. [[User:Theme|Theme]] ([[User talk:Theme|talk]]) 06:49, 12 November 2016 (UTC)
::Uranus had been observed on many occasions before eventually being recognised first as a comet then as a planet; no calculation. A calculation did help find Neptune but had also been seen by multiple observers prior to that; there was already real evidence that it existed. Pluto was discovered by accident based on a faulty calculation so you could add it to Vulcan. Nothing in the Kuiper Belt is big enough to cause the perturbations that would allow for their position to be calculated in advance. [[Special:Contributions/198.41.239.32|198.41.239.32]] 06:50, 14 November 2016 (UTC)
 
  
 
Since the Bullet Cluster has been brought up again, it should be pointed out that it doesn't provide the iron-clad evidence for dark matter that some appear to think it does. Ask a MOND (or MOG)-sympathetic physicist about it and they'll direct you to [https://arxiv.org/abs/astro-ph/0702146 Brownstein & Moffat, 2007], which claims to provide a modified-gravity model that fits the data just as well (or perhaps even better) than λCDM (dark matter). I'm not going to pretend to be able to assess the model they present (or even really understand it), and I'm shamelessly parroting a recent blog-post and commentary by [https://backreaction.blogspot.co.uk/2016/10/modified-gravity-vs-particle-dark.html Sabine Hossenfelder] of the Frankfurt Institute of Advanced Study . But I think the idea that the controversy between λCDM and MOG has been settled is perhaps a distortion of the facts, and those who aren't intimately familiar with the field might be wise to avoid treating it as such. [[User:Charleski|Charleski]] ([[User talk:Charleski|talk]]) 10:19, 12 November 2016 (UTC)
 
Since the Bullet Cluster has been brought up again, it should be pointed out that it doesn't provide the iron-clad evidence for dark matter that some appear to think it does. Ask a MOND (or MOG)-sympathetic physicist about it and they'll direct you to [https://arxiv.org/abs/astro-ph/0702146 Brownstein & Moffat, 2007], which claims to provide a modified-gravity model that fits the data just as well (or perhaps even better) than λCDM (dark matter). I'm not going to pretend to be able to assess the model they present (or even really understand it), and I'm shamelessly parroting a recent blog-post and commentary by [https://backreaction.blogspot.co.uk/2016/10/modified-gravity-vs-particle-dark.html Sabine Hossenfelder] of the Frankfurt Institute of Advanced Study . But I think the idea that the controversy between λCDM and MOG has been settled is perhaps a distortion of the facts, and those who aren't intimately familiar with the field might be wise to avoid treating it as such. [[User:Charleski|Charleski]] ([[User talk:Charleski|talk]]) 10:19, 12 November 2016 (UTC)

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