Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: It's Alive! Spontaneous Motion of Shear Thickening Fluids Floating on
  the Air-Water Interface   In this fluid dynamics video, we show the spontaneous random motion of thin
filaments of a shear-thickening colloidal dispersions floating on the surface
of water. The fluid is a dispersion of fumed silica nanoparticles in a low
molecular weight polypropylene glycol (PPG) solvent. No external field or force
is applied. The observed motion is driven by strong surface tension gradients
as the polypropylene glycol slowly diffuses from from the filaments into water,
resulting in the observed Marangoni flow. The motion is exaggerated by the thin
filament constructs by the attractive interactions between silica nanoparticles
and the PPG.

30
The categories of this paper are: q-alg
2
The categories of this paper are: math
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
20
The categories of this paper are: acc-phys
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th