"My profession is to be forever journeying,
to travel about the Universe
so that I may know all its conditions."

Abu Ali ibn Sina (Avicenna), 980-1037,
physician, philosopher, mathematician and astronomer

Arif Babul

In the News
Scientist, an Artist?  Trangressing Boundaries
I was recently invited to participate in art exhibition titled "SPHERE". There, as part
of an international group exhibition of contemporary explorations of "the sphere" by
contemporary artists were two video installations by myself titled "Cosmological
Spheres", which made use of actual numerical by two collaborators as part of our
larger study on the formation and evolution of structure in the Universe... more

The Art of Physics: ...Seeing the Unseen
The above link will bring up an article published in the March 2006 issue of
PI in the Sky magazine. This article had its origins in an exhibition that Dr. Margret
Fincke-Keeler, a colleague in the Department of Physics and Astronomy, and I
organized in commemoration of the World Year of Physics. The exhibition can be
viewed virtually at:
            ONLINE EXHIBITION: The Art Of Physics
                  Curriculum Vitae
Contact Information
My Research:   An Overview for Non-specialists
Albert Einstein said that the most incomprehensible thing about the Universe is that
it is comprehensible. For UVic astrophysicist Dr. Arif Babul, the Universe is more
comprehensible each day. In fact, he believes astronomers are on the the brink of
explaining the origin of the Universe.
Since the beginning of human civilization we have been wondering how the Universe
came into being, how life evolved; how it all came together," says Babul. We are
living on the threshold of being able to answer those questions. It's a euphoric feeling."
Babul researches how our universe evolved from an extremely smooth state into a rich
to a bejeweled necklace, a spider's web with delicate filaments, or frothy bath ... more

Research Accomplishments
Current Research Interest
Preprints from Astro-ph (1993- )
Publications from ADS
Islam:   The Well of My Social Conscious
     Far from being one-dimensional personalities, as popular caricatures would have
     us believe, scientists are often activists and passionate commentators, engaging in
     various broader issues that affect society. In my own case, as a practising Ismaili
     Muslim, my faith serves both as an inspiration to pursue excellence in the intellectual
     domain - of which science is one facet - and as a reminder that the human existence is
     richly multifaceted and that one should strive to "experience the Universe" in all its
     conditions. This notion of "balance" is a key precept of the Ismaili interpretation of
     Islam. And if this view seems at odds with the popular impressions of Islam, you may
     want to peruse my following essays:  
     I have, thus far, neglected an important question: Who are the Ismaili Muslims? The
     Ismailis are the second largest Shia Muslim community who today form a global
     community that comprises a multiplicity of peoples ranging in their origins from the
     north-west of the Arab world and the Middle East, through Iran and the Indian sub-
     continent to Afghanistan, Central Asia and Western China, with subsequent migrations
     leading to substantial presence in first sub-Saharan Africa and more recently in Europe
     and North America. The Ismailis are the only Muslim community guided by a living
     Imam who, within the Shia tradition, is the only rightful inheritor of the Prophet's
     legacy and authority with regard to ensuring a proper balance between the outward
     expressions of the faith and its spiritual essence in the face of changing times... more


Computing the Universe:
Replicating Nature's Cosmic Sculptures

Observations inform us that the Universe emerged from the fires of Big Bang, nearly 15 billion years ago, in an exceedingly smooth and homogenous state. And yet, gazing out at the Cosmos today, we see a highly organized Universe in which matter is spun into rich web-like chains of galaxies, occasionally punctuated by massive dynamic swarms of up to a thousand bright galaxies held together by their mutual gravity, all woven around giant voids millions of light-years across. Explaining the transition from the smooth beginnings to today's highly organized Universe is one of the Grand Challenges of modern theoretical astrophysics.

As dramatic advances in detector and telescope technologies make it possible to observe the Universe at a fraction of it present age, they also bring a sense of urgency to questions that only a few years ago seemed confined to the territory of theoretical speculation. How do cosmic structures form? How do they acquire their observed features?

The observed present-day features and forms of these wonderous cosmic sculptures are the result of a myriad of inter-related physical processes involving gas, stars, gravity, radiation, and dark matter, a mysterious form of matter that has so far escaped direct detection but makes its presence felt through its gravitational influence on its environs.

Of all the various elements of this fascinating cosmic kaleidoscope, I would argue that perhaps none is as intriguing as clusters of galaxies. Dynamically stable galaxy swarms whose masses are equivalent to anywhere from 10,000 billion suns to a mind-boggling million billion suns and which are roughly 10 million light-years across, clusters of galaxies are the largest, most massive gravitationally bound objects in the Universe. Not surprisingly, understanding how such systems came into being and why they possess the properties that they do is the key goal of my research efforts.

The process of cosmic structure formation can, in a nutshell, be summarized as follows: The distribution of matter, at the earliest times, is smooth except for tiny ripples with relative amplitudes of smaller than 1 part in a 100,000. Gravity amplifies these ripples to form the first generation structures, which under further influence of gravity over the course of roughly 15 billion years, merge to form successively larger systems until finally, the massive cluster emerges. This simple description, of course, glosses over all the details that lends diversity and richness to the Cosmos. For example, clusters contain vast amounts of highly heated gas (temperature ranging from million to hundred million Kelvin) and as such, they radiate copious amounts of X-rays. Though rare, these systems stand out because of the corresponding dramatic concentration of galaxies and because they are among the brightest X-ray sournces in the Universe. In addition, the bulk and concentration of dark matter within these systems is so great that the associated gravity is able to bend and distort light of background sources. The blue arcs seen in this picture of a galaxy cluster taken by the Hubble Space Telescope are examples of gravitational lensing.

For many years now, I have been working with a number of collaborators, such as Professors Tom Quinn of the University of Washington, Neal Katz of the University of Massachussetts, Michael Balogh of the University of Waterloo, Gil Holder of McGill University and Henk Hoekstra of the University of Victoria to name a few, to understand how the various components (gas, dark matter, galaxies and stars) mix and miggle, and give rise to the observed cosmic sculptures. In this quest, powerful supercomputers are among the most important tools at our disposal. Using these computers, we can simulate the entire evolution of the Universe, replicating the Universe's 15 billion year history in anywhere from two weeks to several months, depending on the degree of detail that we wish to capture in the simulations.

The image to the right is a simulated cluster of galaxies. To preview a quicktime movie (warning: a large file; will take a three or four minutes to load) made from the outputs of a numerical simulation showing the formation of the cluster this cluster, click on the image. There are in fact two clips back-to-back. The first one shows the assembly of the dark matter component of the cluster while the second clip shows the responses of the hot gas as it is dragged in by gravity. The movie was made by Professor Tom Quinn using facilities available at the N-Body Shop in the Astronomy Department at the University of Washington.

The aim of our research programme is not only to undertand how the dark matter coalesces to form discreet structure, but also to develop physical insights into what happens to the gas and galaxies as this process unfolds. After all, we can't see dark matter but we can "see" gas and galaxies. However, as we are discovering, the weft and warp of the physical processes interconnecting the three components is so complex that unravelling the threads is proving to be a tremendous challenge. Progress requires cultivating insights and while, in other areas of physics, such insights can be had by designing, say, a table-top experiment and repeating it over and over under different conditions, we have but one Universe and are hardly in a position to tweak conditions here and there, and restart the "whole shebang", except virtually.

A. Babul,
Professor and Director, Canadian Computational Cosmology Collaboration
Dept of Physics and Astronomy, University of Victoria