05-11-2006, 10:36 PM
Here is my question: is it possible to see ships when the only light is a star of the minus-fourth magnitude?
Let me explain.
During the night of 28/29 September 480, the Persians approached Salamis. Early in the morning, they entered the straits, and the rest is history. What could the Greeks know about the Persian movements? Of course, they could hear them. Thousands of oars make an immense noise. But could they see them?
Until 3 o' clock, this must have been impossible, because the only lights were (a) the burning acropolis, (b) the camp fires, and © the planet Jupiter. The first two did not betray movements; the third does not have sufficient light (magnitude -2) to enable people to see during the night.
Things must have changed when Venus rose at three o' clock; this planet was magnitude -4.3; soon, Mars rose, about as bright as Jupiter. This may have created sufficient light to see the Persian ships. Does anyone know?
Let me explain.
During the night of 28/29 September 480, the Persians approached Salamis. Early in the morning, they entered the straits, and the rest is history. What could the Greeks know about the Persian movements? Of course, they could hear them. Thousands of oars make an immense noise. But could they see them?
Until 3 o' clock, this must have been impossible, because the only lights were (a) the burning acropolis, (b) the camp fires, and © the planet Jupiter. The first two did not betray movements; the third does not have sufficient light (magnitude -2) to enable people to see during the night.
Things must have changed when Venus rose at three o' clock; this planet was magnitude -4.3; soon, Mars rose, about as bright as Jupiter. This may have created sufficient light to see the Persian ships. Does anyone know?