Karen Michelle Barad (; born 29 April 1956) is an American feminist theorist, known particularly for their theory of agential realism. Biography They are currently Professor of Feminist Studies, Philosophy, and History of Consciousness at the University of California, Santa Cruz. They are the author of Meeting the Universe Halfway: Quantum Physics and the Entanglement of Matter and Meaning. Their research topics include feminist theory, physics, twentieth-century continental philosophy, epistemology, ontology, philosophy of physics, cultural studies of science, and feminist science studies. Barad earned their doctorate in theoretical physics at Stony Brook University. Their dissertation presented computational methods for quantifying properties of quarks, and other fermions, and in the framework of lattice gauge theory. Barad serves on the advisory board for the feminist academic journals Catalyst: Feminism, Theory, Technoscience and Signs: Journal of Women in Culture and Society. Agential realism According to Barad's theory of agential realism, the universe comprises phenomena, which are "the ontological inseparability of intra-acting agencies". Intra-action, a neologism introduced by Barad, signals an important challenge to individualist metaphysics. For Barad, phenomena or objects do not precede their interaction, rather, "objects" emerge through particular intra-actions. Thus, apparatuses, which produce phenomena, are not assemblages of humans and nonhumans (as in actor-network theory). Rather, they are the condition of possibility of "humans" and "non-humans", not merely as ideational concepts, but in their materiality. Apparatuses are "material-discursive" in that they produce determinate meanings and material beings while simultaneously excluding the production of others. What it means to matter is therefore always material-discursive. Barad takes their inspiration from physicist Niels Bohr, one of the founders of quantum physics. Barad's agential realism is at once an epistemology (theory of knowing), an ontology (theory of being), and an ethics. For this, Barad introduces the neologism ontoepistemology. Because specific practices of mattering have ethical consequences, excluding other kinds of mattering, onto-epistemological practices are always in turn onto-ethico-epistemological. Much of Barad's scholarly work has revolved around their concept of "agential realism," and their theories hold importance for many academic fields, including science studies, STS (Science, Technology, and Society), feminist technoscience, philosophy of science, feminist theory, and, of course, physics. In addition to Bohr, their work draws on the works of thinkers such as Michel Foucault, Judith Butler, Jacques Derrida, and Walter Benjamin, among others. Barad's original training was in theoretical particle physics and quantum field theory. Their book, Meeting the Universe Halfway, (2007), includes a