Final answer:
Indication lights on a train signal various aspects of the train's operation, while visual effects like streaking lights are explained by principles such as the Doppler effect and relative motion. Observations from inside and outside the train can differ due to relativistic effects.
Step-by-step explanation:
When a train operator's indication light is illuminated, it is typically a signal regarding the status of the train or its operations. For instance, it might indicate that the train has received clearance to proceed, there may be a fault or issue that requires attention, or it could be a signal for the engineer regarding speed or track conditions. Several systems and signals are in place to ensure the safety and proper management of railway operations.
The visual phenomena you observe while riding in a train, such as the streaking of lights, can be explained by physics principles like the Doppler effect and motion blur due to the high speed of the train relative to stationary objects. This relative motion creates the illusion of objects moving fast by your window, while the 'dashed' appearance of fluorescent lights results from the flickering of these lights at a frequency that becomes noticeable when you move past them quickly.
In terms of observing light rays or flashes in a moving train, the concepts of relativity come into play, especially when considering the perspective of both a person inside the train and an external observer. The speed and direction of the rail car affect how these observations are made and interpreted. This field of physics examines how different observers perceive motion, light, and time, based on their frames of reference.