Abstract The
motion of a classical particle in an "egg-crate" potential
is modeled in an effort to understand chaotic Hamiltonian dynamics.
While all energy levels are examined, our main interests are in energies
that are associated with anomalous diffusion. However, periodic motion
and classical Brownian motion are observed at various energy levels
in the system. It is noted in particular that particles with energies
between the saddle point of the potential and below the absolute maximum
exhibit anomalous diffusion. The power spectra at these levels exhibit
l/f noise. Algebraic tails are present in the velocity autocorrelation
functions of the energies with l/f noise. Further exploration of these
tails suggests that multiple types are present at different energies.
Abstract An
experimental study of stick-slip friction was conducted using sandpaper
and paper towels. This study models stick-slip friction earthquakes.
A block with sandpaper on its bottom was fixed to a strain gauge by
means of a spring. A paper towel was pulled beneath the block, stretching
the spring, while the position of the block was monitored with a linear
displacement gauge. Readings from the strain gauge and linear displacement
gauge then were used to determine the energy released when the block
slid backwards. Analysis of the data suggests that the interaction
of the sandpaper with the paper towel depends on both the sandpaper
grit size and the surface roughness of the paper towel.
SPS Summer Research Job Site Upgraded, Rolled
into v2.0 of 'The Nucleus' In
July 2004, SPS and ComPADRE rolled out an upgraded and redesigned version
of The Nucleus,
the undergraduate sector of ComPADRE.
The discussion forums on the site have been improved in v2.0, and you
can still post resume information online and search for physics and
science-related summer research jobs in the Summer Research Opportunities
section.
Last
year, our jobs database provided students with access to roughly 1,000
summer science opportunities at more than 140 research sites! We plan
to have even
more submissions this year, so stay tuned. ComPADRE, the physics and
astronomy digital library, is part of the NSF-NSDL.
Present Your Research at a Professional Society Meeting SPS
holds sessions for members to present their undergraduate research at
many professional society meetings around the United States each year.
Both poster and oral sessions are conducted at meetings of the American
Physical Society (APS), the American Association of Physics Teachers,
and the American Geophysical Union, just to name a few. Travel grants
are available for those who regisiter the earliest.
You
can find the meeting announcements, dates and abstract deadlines in
the SPS
Meetings section of the SPS national website.
The
motion of a classical particle in an "egg-crate" potential
is modeled in an effort to understand chaotic Hamiltonian dynamics.
While all energy levels are examined, our main interests are in energies
that are associated with anomalous diffusion. However, periodic motion
and classical Brownian motion are observed at various energy levels
in the system. It is noted in particular that particles with energies
between the saddle point of the potential and below the absolute maximum
exhibit anomalous diffusion. The power spectra at these levels exhibit
l/f noise. Algebraic tails are present in the velocity autocorrelation
functions of the energies with l/f noise. Further exploration of these
tails suggests that multiple types are present at different energies.
An
experimental study of stick-slip friction was conducted using sandpaper
and paper towels. This study models stick-slip friction earthquakes.
A block with sandpaper on its bottom was fixed to a strain gauge by
means of a spring. A paper towel was pulled beneath the block, stretching
the spring, while the position of the block was monitored with a linear
displacement gauge. Readings from the strain gauge and linear displacement
gauge then were used to determine the energy released when the block
slid backwards. Analysis of the data suggests that the interaction
of the sandpaper with the paper towel depends on both the sandpaper
grit size and the surface roughness of the paper towel.
In
July 2004, SPS and ComPADRE rolled out an upgraded and redesigned version
of 
even
more submissions this year, so stay tuned. ComPADRE, the physics and
astronomy digital library, is part of the 
SPS
holds sessions for members to present their undergraduate research at
many professional society meetings around the United States each year.
Both poster and oral sessions are conducted at meetings of the American
Physical Society (APS), the American Association of Physics Teachers,
and the American Geophysical Union, just to name a few. Travel grants
are available for those who regisiter the earliest.