In the way that boats and planes are travelling faster than they appear to be, because the water and air themselves are moving.
Speaking only of waterborne transportation, this gain for current would have to be proportional to the speed of the vessel.
Lets set up a hypothetical voyage. We have two ships (
Alpha and
Bravo) traveling along a line of latitude going west. And so we have numbers to work with, lets say that voyage is 2500 nautical miles from Port A in the east to Port B in the west.
Alpha and [/i]Charlie[/i] both go 25 knots (nautical miles per hour) while
Bravo and
Delta only go 10.
Assume there is a current flowing from east to west at 5 knots (about the speed of the Gulf Stream ([url]http://en.wikipedia.org/wiki/Gulf_Stream[/url)).
Alpha with a speed made good of 30 knots would expect to complete the voyage in 83.3 hours, while the
Bravo making good 15 knots would expect to complete the voyage in 166.7 hours. This is compared to 100 hours and 250 hours respectively.
Alpha sees an 17% improvement while
Bravo sees a 33% improvement.
On the return voyage,
Alpha would only be making good 20 knots, so the voyage would take 125 hrs.
Bravo would only be making good 5 knots and would complete the voyage in 500 hrs.
In order for FE theory to be correct, the return voyage would have to be the same length as the outbound voyage. This would require a 5 knot counter-current running along the exact same course line.
Now, please explain to me how, if these currents exist...
1. These currents have not been measured or observed.
2. These currents can be bi-directional simultaneously
3. These currents can be traveled in an infinite number of course lines between various ports, regardless of direction.
4. Celestial observations don't detect abnormal speed rates that would be required to mislead navigators about the true distances between ports.