Novel Tests of Gravity Below Fifty Microns

College of Natural Resources & Sciences

Theories attempting to unify the Standard Model and General Relativity often include features that violate the Weak Equivalence Principle and gravitational Inverse-Square Law. Motivated by these considerations, undergraduates and faculty at Humboldt State University are operating an experiment to probe gravitational interactions below the 50-micron length scale. The experiment employs a torsion pendulum whose twist is measured as an attractor mass is oscillated nearby. The size and distance dependence of the torque variation provides a means to determine the existence of deviations from expected behavior at untested scales.

Novel Tests of Gravity Below Fifty Microns

College of Natural Resources & Sciences

Physical processes regarding gravity are well understood on the scale of planetary distances but pose challenges in measurements at very short distances. Theories such as the Inverse Square Law (ISL) and Einstein’s Weak Equivalence Principle (WEP) of General Relativity have been tested over distance scales from 1 cm to infinity [1]. Reliable measurements of gravitational forces at scales smaller than a centimeter carry significant challenges. The non-gravitational forces that are generally negligible at the scale of everyday objects have a much more substantial effect in the sub-centimeter regime. Our experiment seeks to measure gravity at these close distances.

Novel Tests of Gravity Under 50 Microns

Abby Keltz, Physics & Astronomy Undergraduate Student

College of Natural Resources & Sciences

Attempts to unify the Standard Model and General Relativity often include features that violate the Weak Equivalence Principle (WEP) and/or the gravitational Inverse-Square Law (ISL). A violation would question our understanding of gravity. To further understand this, undergraduate researchers and faculty at Humboldt are experimenting to measure gravitational interactions below 50 microns. The experiment uses a composition dipole torsion pendulum next to an oscillating mass. This creates torque on the pendulum, the magnitude of which may provide evidence for deviations in the WEP or ISL.

Observer Bias of Giant Kangaroo Rat Precinct Indexing

College of Natural Resources & Sciences

This was a side-project of the Carrizo Ecosystem Project where two observers independently surveyed precincts of the Federally Endangered Giant kangaroo rat (Dipodomys ingens) on 10 plots in the Carrizo Plain National Monument, San Luis Obispo County, California. The goals were to note the bias between observers, to determine if the number of active precincts correlate with the current population density estimates, and to determine if indexing Giant kangaroo rat (GKR) precincts is a reliable method for determining the current GKR population status.

Ocean Acidification and Surfgrass Buffering on Calcifying Intertidal Organisms

College of Natural Resources & Sciences

Our project addresses the question of whether Phyllospadix spp., a surfgrass, can effectively buffer calcium carbonate uptake by calcifying intertidal organisms. This question has significant ramifications for the Humboldt County coastline, which is considered an ocean acidification “hot spot” due to its exposure to acidic water during periods of upwelling. Our group will observe Phyllospadix spp. and it's influence on calcium carbonate deposition on cockle clams and articulated coralline algae . The results will vary due to the abundance of Phyllospadix spp. and invertebrates in each aquarium, and will determine if the calcification rate will be higher in the presence of Phyllospadix spp.

Offshore Wind Resource Assessment

College of Natural Resources & Sciences

Offshore wind energy has enormous potential to help meet California’s 100% clean electricity target. The Schatz Energy Research Center at Humboldt State University is studying the feasibility of offshore wind farms in Northern California. One project, funded by the Bureau of Ocean Energy Management (BOEM), models the power generation from different size offshore wind farms including 50, 150 and 1,800 MW, each located 20-30 miles offshore. The results show that the wind speeds in this region are some of the highest on the West Coast, producing up to 7,540 GWh/year for the largest MW wind farms. This represents 900% of Humboldt County’s electrical needs and 3.8% of California’s demand.

Oh Sh*t! Roosevelt Elk Spread Invasive Plants

Elizabeth Luttrell, Wildlife Undergraduate Student

College of Natural Resources & Sciences

Invasive plants and Roosevelt elk play important roles within an ecosystem, but knowledge on their interactions and ungulates roles as seed dispersers are limited. This study looked at Roosevelt elk in Humboldt County and if their pellets germinated plants, specifically invasive or native.

On the effects of climate-induced forest disturbances on spider assemblages in Michigan

College of Natural Resources & Sciences

Climatic changes affect the intensity and frequency of forest disturbances (e.g. fire, droughts, and insect outbreaks). During the summer of 2016, we used an experimental forest at the University of Michigan Biological Station (UMBS) to observe spider responses to a simulated insect outbreak. We collected spiders from plots with different disturbance severities via pitfall traps and identified them to the lowest taxonomic level possible in order to compare Shannon-Weiner diversity indices. Our hypothesis that spider diversity would be lower in more disturbed plots was supported. Leaf area index, potential prey abundances, and down woody debris were also found to affect spider assemblages.

On to the Future! for Renewable Energy in Arizona, California, New Mexico, and Texas

College of Natural Resources & Sciences

The data analysis MCM problem asked us to create energy profiles and to understand trends and important variables in order to make future goals for the states Arizona, California, Texas, and New Mexico. We made statistical models for each state to understand trends, as well as to help in the predictions for energy usage in 1925 and 1950. A ranking of each profile was instituted based on an analysis of the given data. Using both the models and the profiles, goals were set for all the states to make together in an Energy Compact to increase renewable energy production and consumption. This was all compiled into a memo for the state's governors.

Only Birds Can Start Wildfires

College of Natural Resources & Sciences

Our creative project is going to revolve around the ecological knowledge of the Chicken Hawk that is from Indigenous people of the Humboldt County area. We want to show the significance that Chicken Hawk has in their culture and how it correlates to scientific research that has been done and is being done on them today. We aim to show how ecological knowledge can be applied to current research and assist modern day scientists.