Photo by Andrew Dobrowolskyj
Professor Georgios H. Vatistas is an expert on vorticesthink of
whirlpoolsand one vortex that especially interests him comes out
of ancient literature: Charybdis, the terrible sea monster that terrified
the sailors in Homers Odyssey, written 800 years before the Christian
Not a suitable subject for scientific study? Vatistas says that vortices
exist on every scale, from the very small (quantum mechanics) to the ordinary
(classical mechanics) and the very large (relativistic mechanics).
A mythological creature does not exactly register in any of those disciplines.
But in his latest paper, Escaping Charybdis Wrath, the professor
of mechanical engineering examines whether there was a strong, sober dose
of empirical scientific observation in mythological accounts of tidal
whirlpools. Vatistas presented the paper at a recent symposium organized
by the Department of Mechanical Engineering, and is submitting it to consumer
No one else in my field has looked at mythological accounts of vortices,
as far as I know. Of course, this is not engineering, but the descriptions
of the vortex are right on the money, in terms of the physics involved.
For example, in The Odyssey, which Vatistas read in the original ancient
Greek version, Charybdis has both sucking and belching phases every day.
Odysseus, the protagonist, crossed the whirlpool during the sucking phase.
As Vatistas points out in his paper, this is an early explanation of why
ships can be sucked in, then reappear in a disintegrated form.
Vatistas also examined a short story by Edgar Allen Poe, A Descent into
a Maelstrom, about a fishermans terrifying experiences inside a
Vatistas points out that Homer and Poe must have been using empirical
evidence, sometimes enhanced by their imaginations, most likely through
accounts by sailors of the time. Poe correctly notes, for example, that
the larger the bodies, the more rapid their descent; it is
now known that gravity drives a boat down into a whirlpool, so heavier
objects are the first to go.
Vatistas concludes his paper by wryly suggesting that the observations
and experiences of fishermen and explorers of that time trump scientific
observation in some ways.
In spite of approximately 3,000 years of development in science,
we find ourselves in the awkward position of not being able to suggest
to Odysseus a substantially better navigational plan [around Charybdis].
Mythology in science
Vatistas says that it is fitting to ferret out the science in mythology,
since there is a fair amount of mythology in science.
We take a lot of scientific axioms on faith; for example, energy
cannot be created or destroyed, which is a fundamental belief in
We accept it because it hasnt been disproven. But it hasnt
been proven either; if thats not mythology, what is? Often, we accept
a set of rules based on our experiences, then we construct a theory that
explains it. And if we learn that an axiom doesnt explain everything,
we come up with a better axiom.
His examination of Homer and Poe was essentially a change of pace from
the work he usually does in fluid dynamics, which is the study of the
forces involved in the flow of gases and liquids. Vortex research has
been the focus of the bulk of his research in that field, from mathematical
models to industrial applications.
Vatistas first made his mark in his PhD thesis, which he completed here
at Concordia in 1984, in which he introduced what is now known as the
Vatistas Vortex Model, a mathematical model for computer simulations of
the velocity of any vortex, on any scale. He recently expanded on the
original paper with one on a family of models in 1999.
In a recent project for Pratt and Whitney, Vatistas helped improve wind-tunnel
testing for gas turbine engines. In a more surprising application of his
mathematical models, Vatistas recently collaborated with medical researchers
at the Royal Victoria Hospitals Department of Cardiovascular Surgery.
He helped confirm a theory about the development of arteriosclerosis (hardening
of the arteries) in the abdominal aorta, a major artery leading to the
Vatistas and his team conducted a simulation of blood flow in the abdominal
aorta, using the numerical models they developed. The equations
are the same; we just adjusted them for the geometry in the aorta,
We tested a theory which states that areas in arteries exposed to
sheer stress are more prone to arteriosclerosis. Areas where arteries
branch out undergo more stress, which can cause an injury. The scab then
catches cholesterol. Medical studies had suggested that this was a risk
factor, but we were able to confirm it.
Part of Vatistass research is sponsored by NSERC.