• Physics Core Facilities
  • Physics of Complex Systems
  • Condensed Matter Physics
  • Particle Physics and Astrophysics
  • SRITP
  • Colloquia
    Date:
    08
    January, 2026
    Thursday
    Hour: 11:15-12:30

    Physics Colloquium

    זֶה סַבּוֹן, סוֹב סוֹב סוֹב: Spinning a tale about liquid crystals

    Weissman Auditorium
    Prof. Randall D. Kamien

    The discovery of the cholesteric ushered in the study of liquid crystalline phases and phenomena.  As a structure periodic on the micron length scale, the cholesteric acts as a diffraction grating, affording a labradorescent splendor to the casual observer. While these discoveries were being made, Maxwell developed the theory of canal surfaces; surfaces swept out by a sphere of varying radius moving along an arbitrary path.  I will use a new observation of cholesteric droplets to explain the connection between canal surfaces, focal conic domains, and Apollonian packing. The power of geometric thinking will be highlighted.
  • Seminars
    Date:
    11
    January, 2026
    Sunday
    Hour: 13:15-14:30

    The Clore Center for Biological Physics

    Structure in Prosody

    Prof. David Biron   |   

    Lunch at 12:45

    Prosody, by and large, is the variation in pitch, timing, and loudness that gives speech its musical quality. It is pivotal in human communication, yet its structure and meaning remain subjects of ongoing research. I will describe a data-driven model for English prosody based on large-scale analysis of spontaneous conversations. As a first step, we identified approximately 200 discernible prosodic patterns, i.e., pitch contours typically spanning 1-4 words that we view as building blocks of a prosodic vocabulary, and outlined their properties and communicative meanings. Next, we revealed a Markovian logic, akin to a syntax, affecting how these elementary building blocks concatenate into coherent utterances. We further identified distinct compound functions associated with pairs of consecutive patterns and demonstrated that this Markovian structure is significantly more prevalent in spontaneous prosody compared to scripted speech. These findings offer insights into the underlying mechanisms of conversational prosody, empirically informing and refining existing theoretical concepts in linguistics. The methodology of combining unsupervised clustering analysis of large speech datasets with careful manual annotation could guide future research aimed at refining our model and expanding it to other languages.
  • Seminars
    Date:
    13
    January, 2026
    Tuesday
    Hour: 13:15-14:30

    Special Clore Center for Biological Physics

    Network Resilience Theory of Aging

    Dr. Bnaya Gross   |   

    Lunch at 12:45

    Two major theories compete to explain the origin of aging. The first, proposed by Leo Szilard in 1959, attributes aging to DNA damage. The second, articulated by Robin Holliday in the 1980s, emphasizes epigenetic alterations. While both reveal plausible molecular origins of aging, they leave important puzzles unresolved. First, mutation and epimutation burdens increase linearly with age, whereas aging phenotypes exhibit strongly nonlinear behavior. Second, key aging phenotypes cannot be traced to specific genetic or epigenetic changes; instead, they emerge collectively from their cumulative effects on cellular function.

    In this talk, I will present a network resilience theory of aging that resolves these puzzles. Network resilience is formalized as the ability of a network to sustain its basic functions under changes in its topology and dynamical variables. Our theory conceptualizes aging as a progressive loss of network resilience as cells approach a novel critical mutation-epigenetic line. We identify two regimes of cellular stability, with young cells remaining resilient while older cells exhibit increased susceptibility. Using GTEx data and numerical simulations, we link transcriptional noise to cellular susceptibility and reproduce delayed immune activation observed in aging. Overall, our theory offers a novel perspective on aging based on resilience and critical phenomena.