Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: What Hubble really meant by late and early type: simply more or less
  complex in appearance   It is widely written and believed that Edwin Hubble introduced the terms
`early' and `late types' to suggest an evolutionary sequence for galaxies. This
is incorrect. Hubble took these terms from spectral classification of stars to
signify a sequence related to complexity of appearance, albeit based on images
rather than spectra. The temporal connotations of the terms had been abandoned
prior to his 1926 paper on classification of galaxies.

22
The categories of this paper are: chao-dyn
7
The categories of this paper are: hep-th
30
The categories of this paper are: q-alg
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
16
The categories of this paper are: stat
21
The categories of this paper are: adap-org
9
The categories of this paper are: nlin
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
2
The categories of this paper are: math