english: Light takes exactly one microsecond to go between lines (by definition). =================== The answer to this problem will be given (and explained) here as soon as I have time to write it down, probably during the first part of 2000.
non_english: ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡. ➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡. ➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡➡