The problem of establishing a theory of measuring the one way speed of light has not yet been further tackled since Galileo proposed the theory of measuring the two-way speed of light 400 years ago.

• 摘要自伽利略提出双程光速测量原理以来，400年间人们一直未能进一步解决单程光速测量原理难题，其原因是由于人们陷入了测量单程光速必须引入另一已知速度的对钟信号来同步异地时钟的思维误区；