Modernity is typically narrated as a linear timeline—feudalism yields industrialism, which yields post-industrialism—in a progression measured by clock and calendar. This essay proposes a radical re-grounding of modernity in material phase-states rather than historical eras. Phase-State Modernity is introduced as a non-temporal framework built on the four classical states of matter: solid, liquid, vapor, and plasma. Each “phase” of modernity is defined by a distinct material logic and energetic intensity, corresponding to particular modes of governance, economic organization, knowledge structures, and cultural ethos. In moving from Solid Modernity (stable, hierarchical, territorial) to Liquid Modernity (fluid, networked, adaptive) to Vapor Modernity (diffuse, intangible, volatile) and ultimately to Plasma Modernity (ionized, crisis-prone, transformative), we trace how “all that is solid melts into air” and beyond. We argue that this phase-state lens reveals the entropic costs and tipping points of extractive modernity, challenging Western linear time and GDP-growth orthodoxies. Drawing on thinkers such as Bruno Latour, Donna Haraway, Gilles Deleuze, and Yuk Hui, the essay emphasizes co-agency with non-human actors and an ecological-logical turn in governance. The Oxygenerate Exchange, a proposed plasma-phase economic institution, is presented as a prototype that pegs currency to oxygen generation and planetary health. Blending philosophical analysis with poetic reflection, this paper articulates a new material vision of modernity—one measured not by chronology but by the changing state of our collective socio-material “substance.” See: https://tieutieulephung.substack.com/p/phase-state-modernity-solid-liquid