New analysis throws wrench in formation theory of spirals in galaxies

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The uncertainty of science: A new analysis of over 6000 galaxies suggests that a long-held model for the formation of spirals in galaxies is wrong.

[Edwin] Hubble’s model soon became the authoritative method of classifying spiral galaxies, and is still used widely in astronomy textbooks to this day. His key observation was that galaxies with larger bulges tended to have more tightly wound spiral arms, lending vital support to the ‘density wave’ model of spiral arm formation.

Now though, in contradiction to Hubble’s model, the new work finds no significant correlation between the sizes of the galaxy bulges and how tightly wound the spirals are. This suggests that most spirals are not static density waves after all.

Essentially, we still have no idea why spirals form in galaxies.


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  • Phill O

    Water, Earth, Fire and Air theory of matter dominated for quite awhile.

  • Terrence

    My theory is that two flat galaxies merge by spiraling in on each other. The galactic centers produce density waves that are the arms of the new galaxy.

  • pzatchok

    My idea is its in part related to the age of the galaxies.

    Not counting Galaxies that have interacted with other galaxies.

    The older the galaxy the longer it has had to compress, and like water going down a drain it starts to spin and then swirl creating “Arms” or waves.
    The number of arms is random or at least related to varying matter densities in the swirling galaxy.

    I look at theories like this are in the end trying to set rules to the seeming randomness of the universe, without knowing 99% of the factors.

  • wayne

    here, there, and everywhere…

    Sackler Lecture:
    “Galaxy Evolution in 3D”
    Lisa Kewley 2016

    Joel Primack:
    “New Insights on Galaxy Formation from Comparing Simulations”
    Talks at Google 2017

    “An Electric Universe View of Stellar and Galactic Formation”
    Natural Philosophy Alliance 2012

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