Image:Spiral galaxy arms diagram.png

A vector version of this image (SVG) is available. It should be used in place of this raster image when superior. Image:Spiral galaxy arms diagram.png  Image:Spiral galaxy arms diagram.svg For more information about vector graphics, read about Commons transition to SVG. There is also information about MediaWiki's support of SVG images. Български | Deutsch | English | Español | Français | Galego | עברית | Magyar | Bahasa Indonesia | Italiano | 日本語 | 한국어 | Lietuvių | Polski | Português | Русский | Српски / Srpski | Українська | ‪中文(简体)‬ | ‪中文(繁體)‬ | +/-

A diagram of how arms form in spiral galaxies. I made it with the following Metapost program:

Linethickness = 3pt;
scale = 4in;

beginfig(1);
  pickup pencircle scaled Linethickness;

  for i = 0 upto 11 :
    draw fullcircle scaled ((1 - i/12) * scale)
        xscaled 1.6 rotated (-110/11 * i);
  endfor;
  currentpicture := currentpicture shifted (2*scale, scale);
endfig;
end;

Compile with mpost, open in Gimp, resolution 800, "try bounding box", gray, weak anti-aliasing. Crop, save as PNG.

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