More than one hundred years ago, Albert Einstein published his Theory of General Relativity (GR). One year later, Karl Schwarzschild solved the GR equations for a non-rotating, spherical mass distribution; if this mass is sufficiently compact, even light cannot escape from within the so-called event horizon, and there is a mass singularity at the center. The theoretical concept of a 'black hole' was born, and was refined in the next decades by work of Penrose, Wheeler, Kerr, Hawking and many others. First indirect evidence for the existence of such black holes in our Universe came from observations of compact X-ray binaries and distant luminous quasars. I will discuss the forty-year journey, which my colleagues and I have been undertaking to study the mass distribution in the Center of our Milky Way from ever more precise, long-term studies of the motions of gas and stars as test particles of the space time. These studies show the existence of a four million solar mass object, which must be a single massive black hole, beyond any reasonable doubt. Even date: 9/2/2023 Speaker: Prof. Reinhard GENZEL Hosted by: PolyU Academy for Interdisciplinary Research
This course provides a thorough introduction to the principles and methods of physics for students who have good preparation in physics and mathematics. Emphasis is placed on problem solving and quantitative reasoning. This course covers Newtonian mechanics, special relativity, gravitation, thermodynamics, and waves.
This mini-lecture introduces the future battery. The Faculty of Applied Science and Textiles (FAST) and the Institute of Textiles & Clothing (ITC) organized the mini-lecture series for more than three years. The lectures aim to enrich students' knowledge in creative perspectives and arouse their interest in Sciences, Fashion and Textiles. In view of the unpredictable development of the COVID-19 pandemic, the upcoming mini-lecture Series will be switched from face-to-face mode to online mode.
An online lecture on the topic of "What is Microgravity? Discovering Interesting Phenomena in Microgravity".This lecture of “Science World: Exploring Space to Benefit Mankind” Education Programme in the 2021/22 school year for secondary students, which aims to cultivate the interest of local youth in space science and elevate their enthusiasm for participating in the development of space technology.
Physicist Werner Heisenberg said, "When I meet God, I am going to ask him two questions: why relativity? And why turbulence? I really believe he will have an answer for the first." As difficult as turbulence is to understand mathematically, we can use art to depict the way it looks. Natalya St. Clair illustrates how Van Gogh captured this deep mystery of movement, fluid and light in his work.
In this screencast, you'll observe two vehicles moving across the screen at different rates then describe the motion. Additionally, you'll select the corresponding graphs of distance vs. time, velocity vs. time, and acceleration vs. time for each vehicle.