

You know you didn’t know about the loop initially. Therefore, something you did without that knowledge caused it. Making changes, based on the new info will change the outcome to something different.
You wouldn’t just turn around without cause in the original loop. Doing so, with your only reason being the new knowledge will change the outcome.






















Lasers are both coherent (all the photons line up) and monochromatic (all the photons have basically the same energy). This makes them very easy to focus to a small point and/or make directional.
Diode lasers are effectively LEDs, tuned to these properties.
Lasers let you get a lot of power down a VERY small hole. They also allow you to send multiple colours down the same fibre, multiplying its bandwidth.