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Proceedings Paper

A method of comparing the speed of starlight and the speed of light from a terrestrial source
Author(s): Jingshown Wu; Shenq-Tsong Chang; Hen-Wai Tsao; Yen-Ru Huang; San-Liang Lee; Cheng-Chieh Chang; Wei-Cheng Lin; Ho-Lin Tsay; Yi-Lung Wang; Po-Hsuan Huang; Ming-Ying Hsu; Chia-Wei Hsu; Shu-Chuan Lin; Yung-Jr Hung; Ye-Li Shiu; Yung-Chung Hsiao; Je-Yuan Chang; Din Ping Tsai; Ting-Ming Huang; Hong-Tsu Young; Yi-Cheng Liu; Chung-Min Chang; Wei-Chieh Chiang; Ji-Ying Huang; Ya-Hsin Chen
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Paper Abstract

The speed of light is an important physical parameter. Currently it is a common belief of the constance of the speed of light regardless of the relative velocity between the source and the observer. Because the speed of light is very fast, if the relative velocity is small compared with the speed of light, it is difficult to detect the effect of the relative velocity on the measurement of the speed of light. In this paper we present a method of comparing the speeds of starlight and the light emitting from a terrestrial source. We use a telescope to collect the light from the star having significant relative velocity with respect to the earth, e.g. Capella. Then we modulate the starlight and the light emitted from the local source into pulses i.e. these pulses leave the modulator simultaneously. After travelling 4.2 km, these pulses are detected by a receiver. If the starlight and the terrestrial light have the same speed, then these pulses must arrive at the receiver at the same time. Our results show that the arrival times of the pulses of starlight are different from that of the local light. For example, the Capella is leaving away from the earth. The Capella pulses arrive later than the local light pulses. It indicates that the speed of Capella starlight is slower than the common believed value, c. The presented method uses one clock and one stick, so the clock synchronization problem and any physical unit transformation can be avoided.

Paper Details

Date Published: 1 October 2013
PDF: 12 pages
Proc. SPIE 8832, The Nature of Light: What are Photons? V, 883203 (1 October 2013); doi: 10.1117/12.2023127
Show Author Affiliations
Jingshown Wu, National Taiwan Univ. (Taiwan)
Shenq-Tsong Chang, Instrument Technology Research Ctr. (Taiwan)
Hen-Wai Tsao, National Taiwan Univ. (Taiwan)
Yen-Ru Huang, National Taiwan Univ. (Taiwan)
San-Liang Lee, National Taiwan Univ. of Science and Technology (Taiwan)
Cheng-Chieh Chang, National Taiwan Univ. (Taiwan)
Wei-Cheng Lin, Instrument Technology Research Ctr. (Taiwan)
Ho-Lin Tsay, Instrument Technology Research Ctr. (Taiwan)
Yi-Lung Wang, National Taiwan Univ. (Taiwan)
Po-Hsuan Huang, Instrument Technology Research Ctr. (Taiwan)
Ming-Ying Hsu, Instrument Technology Research Ctr. (Taiwan)
Chia-Wei Hsu, Instrument Technology Research Ctr. (Taiwan)
Shu-Chuan Lin, National Taiwan Univ. of Science and Technology (Taiwan)
Yung-Jr Hung, National Taiwan Univ. of Science and Technology (Taiwan)
Ye-Li Shiu, National Taiwan Univ. of Science and Technology (Taiwan)
Yung-Chung Hsiao, National Taiwan Univ. (Taiwan)
Je-Yuan Chang, National Taiwan Univ. (Taiwan)
Din Ping Tsai, Instrument Technology Research Ctr. (Taiwan)
Ting-Ming Huang, Instrument Technology Research Ctr. (Taiwan)
Hong-Tsu Young, National Taiwan Univ. (Taiwan)
Yi-Cheng Liu, National Taiwan Univ. (Taiwan)
Chung-Min Chang, National Taiwan Univ. of Science and Technology (Taiwan)
Wei-Chieh Chiang, Instrument Technology Research Ctr. (Taiwan)
Ji-Ying Huang, National Taiwan Univ. (Taiwan)
Ya-Hsin Chen, National Taiwan Univ. (Taiwan)

Published in SPIE Proceedings Vol. 8832:
The Nature of Light: What are Photons? V
Chandrasekhar Roychoudhuri; Al F. Kracklauer; Hans De Raedt, Editor(s)

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