hebel. today · 12 November 202618 / 74

Beyond Familiar · Beyond Familiar

Why brittle stone cylinders split under downward pressure

Maryam Khodadad and her colleagues discovered that brittle stone cylinders split vertically under downward pressure because of friction between the press plates and the sample ends. While compression typically crushes material, the plates grip…

Maryam Khodadad and her colleagues discovered that brittle stone cylinders split vertically under downward pressure because of friction between the press plates and the sample ends (Drew Ponder from Frequency Wave Theory). While compression typically crushes material, the plates grip the specimen and restrict its natural sideways expansion, generating internal tension that pulls the material apart from the center. The team's mathematical model accurately predicted the failure loads for six different brittle materials, including rocks and ceramics, by accounting for the specimen's shape and the degree of confinement at its ends.

  • Neanderthals at Poggetti Vecchi, Italy, charred boxwood surfaces to soften the tough material, making it easier to carve into digging sticks with stone tools (Ilari Mäkelä from On Humans).
  • Researchers developed a gait foundation model using three-dimensional skeletal motion data from 3,328 adults to predict multisystem health phenotypes from movement alone (Science Briefing).
  • Ancient DNA recovered from cave walls in Escoural, Portugal, and Covarón, Spain, confirmed human presence on surfaces that lacked any visible pigment or recognizable images (Nancy Thames).
  • Scientists discovered all five essential nucleobases for DNA and RNA in pristine samples collected from the asteroid Ryugu, indicating these ingredients were widespread in the early Solar System (The Curiosity Files).

Try today · 15 min

Test the friction-splitting effect on a brittle, cylindrical object

Use a small, brittle cylinder like a piece of chalk or a dry ceramic dowel and a standard bench vise or clamp.

You need

  • Brittle cylindrical object (e.g., chalk, dry ceramic dowel, or graphite rod)
  • Bench vise or C-clamp with flat, rigid plates

Steps

  1. Place the cylinder vertically between the two flat plates of your clamp.
  2. Tighten the clamp slowly while observing the cylinder's behavior.
  3. Note whether the material crushes at the contact points or if a vertical crack forms from the center as pressure increases.
  4. Record the failure mode and the approximate degree of confinement provided by your clamp plates.

One email instead of your newsletter pile.

Forward the newsletters you already get (a Gmail filter does it) and tell Hebel your goals. Every morning it reads them with 20,000 others and sends one short email, with one small thing to do today. Fewer emails, not more. Free during beta.

Start my paper →
LinkedIn X

Sources

  1. Drew Ponder, Frequency Wave Theory on hebel. → ✎ Written by a personThis paper explains the mechanics of how confined compression causes brittle materials to split vertically rather than crushing.

  2. Ilari Mäkelä, On Humans on hebel. → ✎ Written by a personThis article lists specific Neanderthal technological achievements, including the use of fire-charring for woodworking and specialized bone tools for leatherworking.

  3. Science Briefing on hebel. →This summary details a study using 3D motion data to predict health phenotypes, highlighting gait as a scalable digital biomarker.

  4. Nancy Thames on hebel. →This piece discusses the recovery of ancient DNA from unpainted cave surfaces, demonstrating that human presence can be detected without visual records.

  5. The Curiosity Files on hebel. →This update reports the discovery of all five DNA and RNA nucleobases in asteroid samples, suggesting life's building blocks existed in space.

More in Beyond Familiar

Uncovering the material traces of ancient lives

Craft as a physical manifestation of the self

Does life hide in the thermosphere or the subatomic void?

Cuadrillas de San Martín preserve three centuries of horseback battle re-enactments

Beyond Familiar yesterday

Lost cities and the erasure of historical geography

Sign in to Hebel first

Likes, your collection and done Hebel need an account. We email you a six digit code; no password.