講題一(對學生)：Basic Concepts and Recent Advances in Modern Optics
現代光學的基本概念和最近進展
Nowadays, lasers can generate beams of truly amazing characteristics: light waves with frequency accurate to 1 Hz and light pulses as short as 10-16 sec (or 30 nm in length) and more intense than all the power plants in the world together generate at a given time. They have led to many exiting developments in optical physics in recent years.? They have also brought questions to some basic concepts in optics:? What is a photon?? Can a photon be a pulse and have a pulse width as short as 10-16 sec?? What is the field strength of a photon confined in a microcavity?? How do we define the polarization of a single-cycle light pulse? These questions and others will be discussed in this lecture.
現今，雷射能產生真正具有令人驚異特性的光束：頻率準確至1赫的光波；短至10-16秒的光脈衝（或30奈米的長度）；能一次產生比全世界的電廠總加還要高的功率。這些導致近年來在光學物理學方面有許多令人興奮的進展，也引發了一些涉及光學基本概念的問題：什麼是光子？光子是脈衝，其脈寬可以短至10-16 秒嗎？拘限在微米腔內的光子的場強度為何？我們如何定義僅一個週期的光脈衝的偏振？這些問題，還有其他，將在本演講中討論。
講題二(對教師)：The Mystery of Water
水的奧秘
Water is the most abundant and important liquid on earth. It is also the most mysterious substance on earth, and possesses a host of anomalous properties, many of which are not yet well understood.? Preference for neighboring water molecules to be hydrogen-bonded is believed to be the reason behind most of the anomalies. It explains, for example, why water is more than dense than ice and why ice can conduct electricity better than water.? This talk will describe some of the anomalous properties and their possible explanation. It will also touch upon questions on surface properties of water and ice: Why is the surface tension of water so high?? Is the surface of neat water (pH=7) acidic or basic?? Why can we skate on ice?? How does lightning occur in atmosphere?
水是地球上最豐富和最重要的液體。它也是地球上最神秘的物質，擁有很多異常的性質，其中有許多至今還不是很了解。一般偏向於把大部分異常性質的原因，歸諸於相鄰水分子的氫鍵連結。舉例來說，它解釋了為何水的密度比冰大；為何冰的導電能力較水佳。本演講將描述水的一些異常性質，並提供可能的解釋，也將會觸及水和冰的表面性質的問題：為何水的表面張力如此高？純水（pH = 7）表面是酸性還是鹼性？為何我們可以在冰面上溜冰？在大氣中如何發生閃電？ |
