2005 marks the 100th anniversary of the contribution to physics made by Albert Einstein in 1905. In particular, his ground-breaking papers on the special relativity (that revolutionized our ideas on space and time), photoelectric effect (that established the particle nature of waves), and Brownian Motion (that established the existence of atoms and led to important developments in statistical physics) were all published in 1905. In 2005, physical societies around the world, including the Physical Society of Hong Kong, will organize various activities to promote physics to the public and celebrate the past 100 fruitful years of physics research.