Domokos and his
team analyzed
the fracture
pattern of a rock
outcrop outside
of Budapest. The
fragments were
roughly squarish.28 November/December 2020COURTESYGÁBOR^ DOMOKOSScience
8
// BY CAROLINE DELBERT //Next, the team conducted fieldwork at Hár-
mashatár-hegy, a mountain overlooking Budapest.
Their analysis of a dolomite-rich outcrop revealed
that fragments were, on average, cubic. These
observations, paired with previously collected
field data—both naturally weathered stone and
rock that had been dynamited by humans—was
compared to the 13 million computer-generated
fragments by performing 4 billion computations.
“It was a surprisingly good match,” says coauthor
Gábor Domokos, Ph.D., a professor of mechanicsScience
Confirms
Plato’s
Theory: Earth
Is Made of
Cubes
W
HAT WOULD YOU GET IF YOU
smashed the Earth into little bits?
To answer that question, scientists
from the U.S. and Hungary ran a
series of simulations illustrating
the ways that rock fractures. The
results help us understand the nat-
ural shapes on Earth and across our solar system.
They also confirmed what philosopher Plato had
theorized in ancient Greece: As you break down
the Earth, it crumbles into cubes.
This explains the distinct fracture patterns
observed in nature, says study coauthor Douglas
Jerolmack, Ph.D., a geophysics professor at the
University of Pennsylvania. “Since fragmenta-
tion is a ubiquitous process that breaks rock and
ice across the solar system, our findings help to
explain the shape and size of planetary materials.”
In the first of the computer simulations
performed by teams from the University of Penn-
sylvania, Budapest University of Technology, and
the University of Debrecen in Hungary, research-
ers created a geometric model in which they carved
an abstract cube into almost 600,000 pieces by
randomly inserting a series of 50 2D planes. All
of the resulting fragments were, on average, cubic.
These pieces were then randomly split apart,
many times, resulting in 13 million fragments.
The numbers of sides, edges, and vertices were
counted, and those outcomes were averaged. While
the resulting fragments weren’t actually millions
of tiny cubes, the averages are cuboid, down to
multiple decimal places.