The emergence of Zhang Heng's seismoscope has a profound historical background. This paper intends to explore the formation and material basis of Zhang Heng's scientific thought. It appears that the simple int...The emergence of Zhang Heng's seismoscope has a profound historical background. This paper intends to explore the formation and material basis of Zhang Heng's scientific thought. It appears that the simple intention of "observing visions and distinguishing good fortune or misfortune"was his motivation to develop the seismoscope. Tracing its historical background,the authors proposed in this paper that the development of this seismoscope started around 128 A. D., and based on perceptual knowledge, two ideas about earthquakes came into being,i. e.,earthquake location could be judged according to the instrument shaking direction, and the earthquake and earth split were essentially different. In the instrument manufacture,Zhang Heng advocated a principle of "making utensils to imitate cosmos". By this principle,the following three problems were readily solved: the seismoscope imitated the response of the suspension system to earthquakes( i. e. natural seismoscope). Technically,the trigger mechanism of the latch was used for reference,and it recorded the physical evidence of earthquake occurrence by an ingenious way of a ball dropping from a dragon's mouth. The solution of these three key problems lead to the emergence of the seismoscope in 132 A. D. and the successful detection of an earthquake in 134 A. D. His invention deepened humanity's knowledge of natural laws, and promoted the development of science and technology in that time and later.展开更多
Schrodinger＇s thought experiment to prepare a cat in a superposition of both alive and dead states reveals profound consequences of quantum mechanics and has attracted enormous interests. Here we propose a straight- ...Schrodinger＇s thought experiment to prepare a cat in a superposition of both alive and dead states reveals profound consequences of quantum mechanics and has attracted enormous interests. Here we propose a straight- forward method to create quantum superposition states of a living microorganism by putting a small cryopreserved bacterium on top of an electromechanical oscillator. Our proposal is based on recent developments that the center- of-mass oscillation of a 15-pro-diameter aluminum mem- brane has been cooled to its quantum ground state （Teufel et al. in Nature 475：359, 2011）, and entangled with a microwave field （Palomaki et al. in Science 342：710, 2013）. A microorganism with a mass much smaller than the mass of the electromechanical membrane will not signifi- cantly affect the quality factor of the membrane and can be cooled to the quantum ground state together with themembrane. Quantum superposition and teleportation of its center-of-mass motion state can be realized with the help of superconducting microwave circuits. More importantly, the internal states of a microorganism, such as the electron spin of a glycine radical, can be entangled with its center-of- mass motion and teleported to a remote microorganism. Our proposal can be realized with state-of-the-art tech- nologies. The proposed setup is a quantum-limited mag- netic resonance force microscope. Since internal states of an organism contain information, our proposal also pro- vides a scheme for teleporting information or memories between two remote organisms.展开更多
基金sponsored by the National Natural Science Foundation of China(40644019)the Special Found of Scientific Research Program for "The Optimization and Design for Reconstruction Models of Seismoscope",China Earthquake Administration
文摘The emergence of Zhang Heng's seismoscope has a profound historical background. This paper intends to explore the formation and material basis of Zhang Heng's scientific thought. It appears that the simple intention of "observing visions and distinguishing good fortune or misfortune"was his motivation to develop the seismoscope. Tracing its historical background,the authors proposed in this paper that the development of this seismoscope started around 128 A. D., and based on perceptual knowledge, two ideas about earthquakes came into being,i. e.,earthquake location could be judged according to the instrument shaking direction, and the earthquake and earth split were essentially different. In the instrument manufacture,Zhang Heng advocated a principle of "making utensils to imitate cosmos". By this principle,the following three problems were readily solved: the seismoscope imitated the response of the suspension system to earthquakes( i. e. natural seismoscope). Technically,the trigger mechanism of the latch was used for reference,and it recorded the physical evidence of earthquake occurrence by an ingenious way of a ball dropping from a dragon's mouth. The solution of these three key problems lead to the emergence of the seismoscope in 132 A. D. and the successful detection of an earthquake in 134 A. D. His invention deepened humanity's knowledge of natural laws, and promoted the development of science and technology in that time and later.
基金the support from Purdue University and helpful discussions with G.Csathy,F.Robicheaux, C.Greene,and V.ShalaevZQY is funded by the National Basic Research Program of China (2011CBA00300 and 2011CBA00302)the National Natural Science Foundation of China (11105136, 11474177 and 61435007)
文摘Schrodinger＇s thought experiment to prepare a cat in a superposition of both alive and dead states reveals profound consequences of quantum mechanics and has attracted enormous interests. Here we propose a straight- forward method to create quantum superposition states of a living microorganism by putting a small cryopreserved bacterium on top of an electromechanical oscillator. Our proposal is based on recent developments that the center- of-mass oscillation of a 15-pro-diameter aluminum mem- brane has been cooled to its quantum ground state （Teufel et al. in Nature 475：359, 2011）, and entangled with a microwave field （Palomaki et al. in Science 342：710, 2013）. A microorganism with a mass much smaller than the mass of the electromechanical membrane will not signifi- cantly affect the quality factor of the membrane and can be cooled to the quantum ground state together with themembrane. Quantum superposition and teleportation of its center-of-mass motion state can be realized with the help of superconducting microwave circuits. More importantly, the internal states of a microorganism, such as the electron spin of a glycine radical, can be entangled with its center-of- mass motion and teleported to a remote microorganism. Our proposal can be realized with state-of-the-art tech- nologies. The proposed setup is a quantum-limited mag- netic resonance force microscope. Since internal states of an organism contain information, our proposal also pro- vides a scheme for teleporting information or memories between two remote organisms.
