The effect of f(T) gravity on an interplanetary clock and its time transfer link

As an extension of the＂teleparallel＂equivalent of general relativity,f（T）gravity is proposed to explain some puzzling cosmological behaviors,such as accelerating expansion of the Universe.Given the fact that modified gravity also has impacts on the Solar System,we might test it during future interplanetary missions with ultrastable clocks.In this work,we investigate the effects of f（T）gravity on the dynamics of the clock and its time transfer link.Under these influences,theΛ-term and theα-term of f（T）gravity play important roles.Here,Λis the cosmological constant andαrepresents a model parameter in f（T）gravity that determines the divergence from teleparallel gravity at the first order approximation.We find that the signal of f（T）gravity in the time transfer is much more difficult to detect with the current state of development for clocks than those effects on dynamics of an interplanetary spacecraft with a bounded orbit with parameters 0.5 au≤a≤5.5 au and 0≤e≤0.1.

Time, Culture and Identity: A Digital and Creative Professional’s Perspective on Interpreting Historical Clocks in Museum Environments

Digital media offer unique opportunities for museums to bring to life the secrets and stories of their historical collections.To bring insight into the process of developing digital media exhibits,this paper presents the perspective of a creative practitioner in approaching technology-and media-based interpretation for collection objects.It follows the Time,Culture and Identity digital workshop held in Beijing in October 2019,which explored and shared ideas about collaborative research and interdisciplinary practice in digital interpretation between academics,institutions,creative practitioners,and developers.Following the direction of the workshop,the paper takes as its focus the clocks and automatons of the imperial collection at the Palace Museum in Beijing.Observations are based on the author’s practice-led experience in running a design studio,Harmonic Kinetic,developing new media exhibits using digital technology and audiovisual media for museums,galleries,and exhibitions in the UK,including the Science Museum,V&A,Barbican,Tate,and the Tower of London.Taking a broad interaction-design-led outlook,the paper explores a personal design perspective for developing interpretive content and considers the particular opportunities and approaches these historical devices suggest.The paper concludes with a final section that reviews the process and reflects on outcomes from the Time,Culture and Identity digital workshop.This explored possibilities for an interpretive exhibit on the Country Scene clock from the Palace Museum collection.

Time, Culture and Identity: Exploring Horological Collections with UK-China Museum Audiences

This paper discusses cross-cultural understanding of museum collections by looking into transnational audience engagement with the imperial clock collection of the Palace Museum in Beijing.The audience research took place in three sites:the Hong Kong Science Museum,the Palace Museum in Beijing,and the Science Museum in London.Audience data were collected using qualitative methods,such as intercept interviews,focus groups,and informal group discussions with non-specialist and specialist audiences across the three locations.The qualitative samples suggest that UK-China audiences draw from different cultural references when they engage with the unique"singsongs"in the imperial clock collection.Despite the divergence of cultural connections made across audiences in the UK and China,it is consistent in the audience data that the appeal of the clocks is reinforced by seeing their movement.The data also indicate a desire to connect with human stories behind the creation,trade,and conservation of singsongs,and expectations for a digital resource that is visually captivating and offers additional insights into the singsongs,such as the demonstration,mechanism,and backstory of the automatons.This paper concludes with a reflection on the implications of audience data for the interpretation strategy of a London-based exhibition featuring the singsongs,and considerations for the development of a digital experience about the imperial horological collections that speaks to audiences across the UK and China.