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Howdy! I'm

A Physicist


Before I came to Okinawa Japan, where I am currently a graduate student, I was a research staff member at North Carolina State University's physics department, which is also where I received my undergraduate degree in physics in 2021. My work there was primarily conducted in Karen Daniels's lab investigating granular physics and soft matter, though I have also worked on high energy hadronic collision simulations with Vladimir Skokov.
Check out some of the projects I am working on below!
For a full list of publications and presentations, see the bottom of this page.

Probing Granular Materials on Asteroids

When we think of asteroids in space, we often think of them as big boulders, or composite objects, flying through space (possibly with baobabs growing on them).

In reality, a large number of these astronomical objects are actually very weakly bound collections of heterogeneous granular materials, since the gravity holding them together can be 4-5 orders of magnitude less than on what we experience on Earth.

Two recent missions have gone to investigate asteroids that fit this description: JAXA's Hayabusa2 mission to Ryugu and NASA's OSIRIS-REx mission to Bennu.

Our goal with this project is to develop optimized procedures for working in these exotic environments with the paradigm of a flexible probe. That is, how should we go about inserting a flexible intruder into these surfaces without causing a large amount of regolith to be ejected?

To investigate this, we simulate these systems in a laboratory environment using photoelastic techniques, which clue us into what is happening on the individual grain scale.

Want more information (including quantitative results)? Check out our paper!

High Energy Hadron Collisions

What are protons made of? How did the early universe form? What happens when two particles run into each other really fast?

All of these questions reside (at least in part) within the realm of high energy particle physics, which looks to explain the fundamental interactions and compositions of particles.

Of particular importance, the theory of Quantum Chromodyanmics has been fantastically useful in helping us to answer some of the above, and related, questions. Through a framework involving "color" charges, squiggly diagrams, and a whole lot of math, physicists can model and predict what happens inside of the protons and neutrons that were once thought to be fundamental.

Some of the biggest physics collaborations in the world investigate these same problems at particle colliders like the LHC and RHIC, so how can we look into the same physics without such fancy tech? By programming of course!

Want some more technical information? Want to run your own simulations in the saturation regime of QCD? Check out the full simulation software here.

Predicting Granular Failure with Network Analysis

A topic of great interest to many different communities, including both granular physicists and geophysicists, is understanding how and when a composite material will "fail". That is, when will there be significant rearrangements on the grain scale that could potentially have a significant effect on the bulk properties of the material?

These failures could look like landslides, stick-slip dynamics, or a whole lot of other things!

My work specifically investigates if these failures can be predicted in a laboratory system of photoelastic particles using only metrics relating to the interparticle forces.

Publications and Presentations

  1. Featherstone, J., Bullard, R., Emm, T., Jackson, A., Reid, R., Shefferman, S., Dove, A., Colwell,J., Kollmer, J. E., & Daniels, K. E. (2021). "Stick-slip dynamics in penetration experiments on simulated regolith.", Planetary Science Journal, 2(6), 243. 10.3847/PSJ/ac3de2
  2. Kollmer, J. E., Featherstone, J., Bullard, R., Emm, T., Jackson, A., Reid, R., Shefferman, S., Dove, A., Colwell, J., & Daniels, K. E. “Probing Regolith-Covered Surfaces in Low Gravity.” Powders & Grains 2021, EPJ Web of Conferences, 10.1051/epjconf/202124902005
  3. Featherstone, J., Bullard, R., Emm, T., Jackson, A., Reid, R., Shefferman, S., Dove, A., Colwell,J., Kollmer, J. E., & Daniels, K. E. "Probing Granular Materials in Extraterrestrial Gravities." APS March Meeting 2021, 02.01.16 Soft matter physics in a geophysical context
  4. Featherstone, J., & Skokov, V. V. (2022). "Numerical package to compute particle production in hadron collision in the dilute-dense approximation of the Color Glass Condensate." In prep. Jfeatherstone/ColorGlass
  5. (Upcoming) Featherstone, J. & Daniels, K. E. "Friction and Failure on the Single Particle Scale." Triangle Soft Matter Workshop 2022