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Credit: M101 -
NASA,
ESA,
CFHT,
NOAO;
Typhoon Rammasun -
MODIS,
NASA
Comparison: Lawrence Anderson-Huang (Ritter Astrophysical Obs., Univ. Toledo)
Explanation:
Uncomfortably close
Typhoon Rammasun (right)
and 25 million light-year distant
galaxy M101 don't seem to
have much in common.
For starters, Rammasun was only a thousand kilometers or so
across while M101 (aka the Pinwheel Galaxy)
spans about 170,000 light-years, making them vastly
dissimilar in scale, not to mention the different
physical environments that control their
formation and
development.
But they do look amazingly alike: each with arms exhibiting the
shape of a simple and beautiful mathematical curve known as a
logarithmic
spiral, a spiral whose separation grows in a
geometric
way with increasing distance from the center.
Also known as the
equiangular spiral, growth spiral, and Bernoulli's
spiral or spira mirabilis, this curve's
rich properties have fascinated
mathematicians
since its discovery by 17th century philosopher
Descartes.
Intriguingly, this abstract shape is much more abundant in nature
than suggested by the striking visual comparison above.
For example, logarithmic spirals can also describe
the tracks of subatomic particles
in a bubble chamber,
the arrangement of
sunflower
seeds and, of course,
cauliflower.
Comparison: Lawrence Anderson-Huang (Ritter Astrophysical Obs., Univ. Toledo)
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Based on Astronomy Picture
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Publications with keywords: spiral galaxy
Publications with words: spiral galaxy
See also: