Although consciousness has been studied for thousands of years, it still remains one of the most mysterious concepts in the world.

“(Consciousness is) awareness, having an experience, being aware of your surroundings or yourself…having a phenomenal aspect of existence,” said Stuart Hameroff, director of the University of Arizona Center for Consciousness Studies and professor emeritus of anesthesiology and psychology at the UA. “It could have been that we would be complex behaving entities going around our business without any inner consciousness…”

Since 1994, Hameroff has been involved in organizing a biannual interdisciplinary conference on the science of consciousness, which opened again this week in Tucson.

Toward a Science of Consciousness hosts around 800 scientists, philosophers, experimentalists, artists and students from different backgrounds and perspectives.

“For the 20th anniversary, we invited the best people in the world, people who’ve been here over the years, people who are doing the best work now…it is pretty much the all-star event,” he said.

The list of 29 speakers include names such as Deepak Chopra, spiritual medicine guru, Roger Penrose, world-renowned physicist and mathematician, and David Chalmers, distinguished professor of philosophy at Australian National University and professor of philosophy at New York University, a press release from the event said.

For a week the speakers explore consciousness through lances of physics, subjectivity and objectivity, time, death, quantum approaches and brain studies.

The conference aims to reflect on 20 years of progress in the studies of consciousness, and to discuss current understanding, dilemmas and future directions, the release said.

Toward a Science of Consciousness is taking place from April 21 to 26 at the Tucson Marriott University Park, 880 E. 2nd St. For more information call 621-9317.