Lizzy & Mark: Week 10

Lizzy's update

Mark and I spoke recently about what we would like to “do” now that we are past the halfway point in our formal residency collaboration. We revisited the tetrahedral collapse toy model. I think it would be interesting to share this concept with a mechanical engineer, someone with knowledge of design and system dynamics. Not only would it be a great project to present once finished, it is helping me understand the concept more clearly, and Mark mentioned he has a desire to hold the model in his hands to help him work out his own thoughts.

We’re both interested in creating some objects that could play a role in demonstrating or illustrating concepts, like the different parts of the structure of the dark matter sheet: walls, filaments, nodes, and voids. I have a number of series inspired by our collaboration that would be wonderful to share in conjunction with some of Mark’s visualizations and writings in the form of an exhibition. The series include traditional pastel and charcoal drawings from data plots in 2D, the “Phase Portraits”, fine paper models of origami folding patterns, and an idea still in its early phases, a print series using the beautiful, simplified, geometric simulation visualizations. I’m also thinking about different forms of traditional animation as well as representing the progression of time in a static way, like a progression of frames shown side by side or stacked in some way.

I am formulating some game plans for those art projects with time frames and budgets. I feel that our collaboration is happening very naturally. We’ve been sharing our progress as it happens, bouncing ideas off of each other, some of them better than others, and it seems like we really have a lot to work with within a wide range

Although it will not be until later this week that we get together via video chat to work on some visualizations, I am planning on getting into my art studio and documenting sketches that I’ve made and working on a few more to share next week.

An interesting conceptual crossover: the grid method as a drawing tool. You take an image that you want to copy and you overlay a grid on it, then recreate the same grid onto your blank canvas, and copy square by square. You’re basically creating a little coordinate system. I don’t have a projector at my current studio, so I’ll be using this method to transfer some of the plot images from Mark’s research! Remnants of the grid transfer system may even find their way into the final pieces...

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Mark's update

I have been working on some visualizations to clarify the idea of the "dark matter sheet" ... a curious object in cosmology is a circular, "perfectly compensated void" -- a density depression in which some matter is scooped out from the middle and placed entirely along a circular ridge around it. 

The first movie shows how the density evolves in time in a computer simulation -- matter evacuates in the middle and piles up along the edge, and then pushes into the region around it (the behavior at the end here is not widely appreciated in cosmology, by the way).

The second movie shows explicitly what is going on in "position-velocity phase space" -- plotting each matter parcel in a space including both its usual position, and its velocity (one velocity coordinate for each position coordinate). In this case, we have a simulation with 2 position coordinates, and formally 2 velocity coordinates, but it was set up in a particularly symmetric way so that all of the velocity is radial. This makes it much easier (i.e. possible at all) to plot all the information in only 3 dimensions. 

You can probably see how the white area in the middle expands (growing thinner -- thus the evacuation, when you project this down to the x-y plane), and the edge moves out, rolling up the rest of the material like a carpet. All the regions here are colored the same way throughout the video, so you can see where stuff is transported.

Besides these videos, Lizzy and I are working on some ideas to represent these kinds of thing with paper, and maybe even gadgets representing and capturing the essence of how rotations of galaxies and filaments between them might occur in the cosmic web. Stay tuned!