4,757 research outputs found
The origin of pointing: Evidence for the touch hypothesis
Pointing gestures play a foundational role in human language, but up to now, we have not known where these gestures come from. Here, we investigated the hypothesis that pointing originates in touch. We found, first, that when pointing at a target, children and adults oriented their fingers not as though trying to create an “}arrow{” that picks out the target but instead as though they were aiming to touch it; second, that when pointing at a target at an angle, participants rotated their wrists to match that angle as they would if they were trying to touch the target; and last, that young children interpret pointing gestures as if they were attempts to touch things, not as arrows. These results provide the first substantial evidence that pointing originates in touch
Ultraviolet avalanche in anisotropic non-Abelian plasmas
We present solutions of coupled particle-field evolution in classical U(1)
and SU(2) gauge theories in real time on three-dimensional lattices. For
strongly anisotropic particle momentum distributions, we find qualitatively
different behavior for the two theories when the field strength is high enough
that non-Abelian self-interactions matter for SU(2). It appears that the energy
drained by a Weibel-like plasma instability from the particles does not build
up exponentially in transverse magnetic fields but instead returns,
isotropically, to the hard scale via a rapid avalanche into the ultraviolet.Comment: 22 pages, 10 figures; v3: small textual changes; updated to
correspond with version to appear in publicatio
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