From: http://www.racc.edu/faculty/AlVanim/pdf/EPChapter5notes.pdf
Thresholds
Absolute Threshold: Minimum stimulation needed to detect a particular stimulus 50% of
the time.
Absolute Sensory Thresholds
•Vision: A single candle flame from 30 miles on a dark, clear night
30 MILES. WOW.
Just thought this was interesting and related to the factual accuracy vs legend and folklore of the "April 19th" story.
We now return you to your regularly scheduled forum surfing...
Boston to Charlestown, 1.06 miles (post office to post office). Thanks, that might be a good to know when dealing with a skeptic.