Katelyn Geleynse presses the button and the machine groans to life. The massive metal plates shift until a half-ton of compressed plastic tumbles out onto the waiting pallet. The crowd cheers. Permanent markers are passed around and everyone takes turns signing the massive block.  

It’s February 16, 2024, and the members of the Promega Sustainability Committee are gathered to witness the first bale of plastic film being ejected from the Madison campus’s new baler. It’s only the first bale, but it represents a major step in the company’s efforts to reduce plastic waste.

“All of this would have gone to the landfill if we hadn’t set up this program,” Katelyn says. “It feels good to know that at least some of my waste is getting a second life.”

Plastic film is notoriously difficult to recycle and takes decades to break down in a landfill. The Promega initiative to divert this waste was started by a small group of employees who noticed a problem and worked for over a year to build a sustainable solution. What began as a small volunteer operation grew to spur capital investment in a process that will rescue around 35,000 pounds of plastic per year.

Your ability to navigate space and time is anchored in your memory, particularly episodic memory, which catalogues the experiences you have in a given location. This type of memory is shaped by complex neural networks firing within your hippocampus. So how exactly do we store memories of the hundreds of things that happen to us in a day, especially when they unfold in the same settings?

There are theories as to how we form single-shot, or “episodic”, memories, many of which center around the activity of place cells, which light up when you are in a specific environment. The idea here is that, with every event that happens in a place, these cells would shift and fire in novel patterns. Scientists at the Zuckerman Mind Brain Behavior Institute at Columbia University questioned this—while it is known that place cell activity can certainly be affected by experiences, they wondered whether there could be an alternative explanation for episodic recall that wouldn’t require the constant remapping of one’s core memory of a place.