Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
But the point is, the quantities that appear in
the thin-lens formula are not distances. They
can't be distances, because they have nontrivial
signs. Similarly, the "focal length" isn't
properly a length, because it has a nontrivial
sign.