由于红色在可见光谱中波长最长,因此可视距离要比其它颜色更远,这就可以理解为什么很多文化中将红色视为危险信号。红色很早以前就被用作火车信号,那时汽车还没出现,而铁路用机械臂板上升下降来代表前方是否有火车驶来。这比较容易理解。
• Green meant "caution" at first
绿色最早用于“警示”
Green's role in lights has actually changed dramatically over time. Its wavelength is next to (and shorter than) yellow's on the visible spectrum, meaning it's still easier to see than any color other than red and yellow. Back in the early days of railway lights, green originally meant "caution," while the "all-clear" light was, well, clear or white. Trains, of course, take an interminably long time to stop, and legend has it that several disastrous collisions happened after an engineer mistook stars in the night horizon for an all-clear. Thus, green became "go," and for a long time, railways used only green and red to signal trains.
长期以来绿色在交通信号灯中的角色发生了巨大变化。可见光谱中,绿色波长因仅次于黄色,因此是除了红色和黄色外最容易看见的颜色。在早期的铁路信号灯中,绿色最初代表“警示”,而无色或白色代表“全线通行”。当然,火车停下来需要非常长的时间,据说由于一名工程师将夜晚天空中的星星误认为全线通行的信号灯,导致了若干起灾难性事故的发生。因此,绿灯成为了“通行”的标志,长期以来铁路也只将红色和绿色作为信号灯。
【交通信号灯为何用红色、黄色和绿色?】相关文章:
最新
2019-01-07
2019-01-07
2019-01-07
2019-01-07
2019-01-07
2019-01-05