About the Hong Kong Laureate Forum

Welcome to the March 2021 issue of the newsletter of the Hong Kong Laureate Forum!

"Science Hunt" online quiz game is coming to an end! We launched the Game last October and deadline for submission of answers for last round of games is 5 April. It has been almost six months since we launched the Game, we are excited to see enthusiastic participation from the community. There are more than 3,000 entries so far, some participants also further enquired about the answers and explanations after we published them on our website, hoping to gain more scientific knowledge.

We would like to take this opportunity to thank our local scientists and organisation for their assistance in providing questions, answers and explanations and to further answer participants’ enquiries in a professional manner. They are:

• Prof Jason CHAN, HKUST
• Dr CHAN Man Ho, EdUHK
• Prof CHU Ming Chung, CUHK
• Dr HO Koon Sing, HKBU
• Prof Tjonnie LI, CUHK
• Consulate General of France in Hong Kong & Macau

Don’t forget that we also have lucky draws for the Grand Prize, Active Participation Prize and Lucky Prize in mid-April. In May, we will launch a new game about interesting scientific terms.

On the other hand, the first-tier review of applications for the inaugural Hong Kong Laureate Forum has been completed, more information on the inaugural Forum will be published on our website and social media, please stay tuned!

Trade Promotion Competition Licence No.: 53749-50

Prophecy Fulfilled?

Reviewing Half a Decade of Gravitational Waves

In 2016, the Shaw Prize in Astronomy was awarded to Ronald Drever, Kip Thorne and Rainer Weiss for conceiving and designing the Laser Interferometer Gravitational-Wave Observatory (LIGO). In particular, the award statement includes the phrase "whose recent direct detection of gravitational waves opens a new window in astronomy". Some five years after the first observation of gravitational waves (from the merger of a pair of black holes), it is worth reviewing whether a new window in astronomy has indeed been opened.

Discoveries from a Wealth of Data

The first discovery of gravitational waves was made during the first so-called observation run, extended stretches of data taking, between September 2015 and January 2016. During this first observation run, Advanced LIGO made two detections of gravitational waves, both originating in the collision of two black holes.

Since the award of the 2016 Shaw Prize, Advanced LIGO has conducted two more observation runs. Altogether, the two Advanced LIGO detectors have generated terabytes of data in which faint traces of gravitational waves are buried within the noise. The data is being searched using complex algorithms, which take months to analyse and verify potential gravitational-wave events.

The periods in between observation runs are used to enhance the sensitivity of the detectors. For example, in the interval between the first two observation runs, the sensitivity of both Advanced LIGO instruments was improved by about 20%, which equals being able to observe 70% more signals (the volume grows with the cube of the distance).

The second observation run was conducted between November 2016 and August 2017. This observation run lifted the total number of detections to 11. The third observation run started in April 2019 and ran until March 2020 when the observation run was suspended due to the COVID-19 pandemic. So far, the data so reported up to October 2019, had added 39 gravitational-wave events to the 11 from the first two observation runs.

Indeed, as improbable as it seems, the detection of gravitational waves has now become commonplace, only five years after the first detection in September 2015. With now 50 gravitational-wave detections we are better able to explore the population of black holes and neutron stars throughout the Universe. This proliferation of gravitational-wave observations has enabled us to generate some exciting new insights.

A Study on Multiscale Kinetic Models with Uncertainties

Kinetic equations are widely used in many important areas such as rarefied gas, plasma physics, astrophysics, and have also seen a host of new applications such as semiconductor device modeling, environmental, social and biological sciences. They describe the non-equilibrium dynamics of a gas system composed of a large number of particles. The solutions to kinetic models determine the probability density functions of the dynamical states of a large number of particles, which usually depend on time, space and velocity. Kinetic equations bridge atomistic and continuum models in the hierarchy of multiscale modeling. The diagram below shows where kinetic equations stand in the hierarchy of different physics models from microscopic to macroscopic:

Figure 1: Physics models of different scales.

The Boltzmann equation, founded by Ludwig Boltzmann in 1872, is one of the most important examples of kinetic models. It is an integro-differential equation that describes particle transport and binary collisions of a rarefied mono-atomic gas. In the past decades, there have been enormous studies on the Boltzmann equation, both in theory and numerical computation.

As for applications of kinetic models, for example, aerospace activities arise in many problems of rarefied gas dynamics. A rich harvest of research activities was achieved in the last fifties and sixties thanks to the spectacular space programs, which led to numerous theoretical and experimental problems concerning flows of neutral and ionized gases.

One of the most significant applications are flows over reentering vehicles, in particular kinetic heating, drag and energy balance of satellites, the exhaust volume of rockets operating at extreme altitudes and in space, design high-atmosphere sounding devices, production of gas clouds at extreme altitudes, etc. The Boltzmann equation also has extensive and important applications in other fields, such as astrophysics, plasma physics, design of particle accelerators or semiconductor devices and so on.

Technology Adoption among the Elderly – Smart Older Adults in the New Decades

Information and communication technology (ICT) keeps advancing at a skyrocketing speed and complexity. Meanwhile, many developed societies are seeing an ageing population as a result of advancement in modern medicine as well as improvement in nutrition and public health. Indeed, in the case of Hong Kong, the number of persons aged 65 and above is projected to account for over 25% of the population in 2030, up from just over 16% in 2017. Adoption of the technology, however, has not been widespread in the elderly population. Many elderlies often have mixed views about the use of technology. Some consider new technology as being complicated and not user-friendly. Costs and privacy are also common concerns. To promote technology adoption among the elderly, family members’ support is often the key. Manufacturers can also assist by improving the products through creating simple and user-friendly devices. Governments may facilitate the adoption by encouraging or even working with non-government organisations (NGOs) to organise promotional activities, coaching sessions and providing continuous support. Technology can enhance the quality of life of the elderly, whether in sickness or in health. Potential benefits are countless.

Healthy Ageing

According to the World Health Organisation (WHO, 2020), healthy ageing "is about creating the environment and opportunities that enable people to be and do what they value throughout their lives". It is a process of maintaining and developing their functional abilities, which could meet their basic needs, keep their mobility, ensure they can build and keep relationships, continue to learn and make decisions as well as contributions to the society. There is an intrinsic correlation between individuals and the environment, which can be the home, community with relationships among people, as well as social policies and system. Individuals’ capacities are also related to physical and mental abilities like memory, hearing and vision, that can be affected by age.

Healthy ageing encompasses active ageing, which requires actions from different bodies and parties to provide resources to the family as well as community. In the local context, to promote healthy ageing, many government departments and public organisations are responsible for elderly services such as the Elderly Health Service under the Department of Health (2018) and The Chinese University of Hong Kong Jockey Club Institute of Ageing, which provide education to elderly on how to age healthily in the aspect of eating habit, mental health, relationship, technology, etc. Among all, technology is becoming the key element in promoting healthy ageing.