What is Ultracold?

Ultracold is a longform newsletter that publishes on a monthly schedule. It reflects my experience as a queer, non-binary, immigrant physicist and science writer living, learning and working in New York.

Every letter consists of:

  • a personal essay processing current events and occurrences in my own life through a lens of science and popular culture

  • a brief rundown of all of my recently published writing

  • media recommendations: music, podcasts, movies, books, newsletter and everything else I am currently consuming and thinking about

  • brief updates on my vegan kitchen adventures

Who is Karmela?

I am a science writer living in Brooklyn, NY. I hold a Ph. D. in theoretical physics and my popular science writing has been published in Scientific American, Slate, WIRED, MIT Technology Review, Quanta Magazine, Physics World, Massive Science and The Xylom. Currently, I am a full-time physics reporter at New Scientist. Previously, I was an Assistant Professor at Bard High School Early College.

Over the past decade I’ve worked as an academic researcher, a mentor, project manager for art productions rooted in science, an advocate for diversity, equity and inclusion in the sciences as well as a labor organizer in higher education.

You can find out more about me by visiting my website karmelapadaviccallaghan.com. Please do also connect with me on Twitter or Instagram.

Why this?

I don’t encounter many voices like mine online or in physical spaces I move through for work and therefore want to use my own to be as loud as I can. I would love for “queer, non-binary, immigrant physicist” to one day be a niche; there should be more of us.

A bit of context…

I started Ultracold in July of 2017 as a minor self-indulgence. It was meant to keep me engaged and honest, and push me to verbalize and work through thoughts and feelings I may have otherwise had a hard time confronting. I also just wanted a space to whine, go on and on about whatever I was cooking and baking, and to pretend that I could be a writer alongside working on my Ph. D. Most of those things are still true.

At the same time, I did finish my Ph. D., I did get married, I did find a full-time teaching job, and then a full-time writing job. Ultracold - referring to my work in the area of physics near absolute zero, many freezing places I’ve lived, first impressions I’ve made with my incurable resting-b*tch-face, and this writing project all at the same time - has followed me around and helped me grow in unexpected and unprecedented ways.

Writing these letters is among the things I most enjoy doing and one that I feel the most ownership over. I commit a lot of time to it and am beyond grateful and flattered every time I see a new reader. Thank you for being here!

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Notes on being a queer, immigrant, nobinary physicist-turned-writer, former teacher and one of those people that just have a very cold-seeming face.


Karmela Padavic Callaghan
Theoretical physicist. Writer. Organizer. Teacher. Croatian in Brooklyn. Podcast superfan. Queer. Vegan.