{
  "id": 7406598,
  "title": "From atomic vibrations to laboratory mechanics: Bridging 20 orders of magnitude in time",
  "url": "https://urgent.news/2026/09/14/from-atomic-vibrations-to-laboratory-mechanics-bridging-20-orders-of",
  "topic": "science",
  "section": "Science",
  "published": "2026-09-14T22:00:06.000Z",
  "source": {
    "name": "Phys.org",
    "slug": "phys-org",
    "url": "https://phys.org/news/2026-09-atomic-vibrations-laboratory-mechanics-bridging.html"
  },
  "original_language": "en",
  "account": "The article discusses bridging a 20 order of magnitude range in timescales from ultrafast atomic motion to laboratory mechanical processes. PMMA, a glassy polymer, responds differently to rapid and slow deformations. While molecular dynamics can model fast atomic movements, it struggles with longer timescales. Conversely, techniques like dynamic mechanical analysis excel at slower deformations. Researchers aimed to develop a unified framework starting from the polymer's atomic structure to predict mechanical properties across these scales. Using non-affine lattice dynamics, the team modeled PMMA's atomic vibrations and their coupling to external deformation. This allowed calculation of the shear modulus, which describes the material's resistance to shear. An important factor was incorporating memory effects, as the polymer's response depends on past deformations. The theory successfully predicted the shear modulus across frequencies ranging from terahertz to millihertz, a range spanning 20 orders of magnitude. This single theoretical curve encompassed behaviors observed in disparate experimental techniques, from molecular dynamics at the fastest frequencies to dynamic mechanical analysis at laboratory speeds. The study revealed distinct physical phenomena at different frequencies: high-frequency behavior driven by molecular bonding networks, non-affine atomic rearrangements reducing the modulus at slower frequencies, and β relaxation processes at around 1 hertz. This unified approach challenges the traditional separation between atomic-scale simulations and macroscopic engineering tests, showing that microscopic physics can be extrapolated to macroscopic behavior when the underlying atomic mechanisms are understood.",
  "summary": "How can we predict the way a real material, such as a polymer, responds mechanically over timescales ranging from the ultrafast motion of atoms to the slow deformations measured in a laboratory? This is a deceptively difficult problem.",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}