The Voynich Manuscript is a cipher because...?

[david]

17th century scientists used to communicate via anagrammed Latin, as they knew how difficult it was to extract its proper meaning.
Witness the famous Galileo code he sent to several compatriots (including Kepler) to prove he was the first to observe the rings of Saturn, before he was ready to reveal all the details. The idea being that he could thus "prove" his discovery if someone else announced it before he was ready.

He sent the following message:
smaismrmilmepoetaleumibunenugttauiras

With no futher explanations. Kepler spent quite some time puzzling over the message and eventually thought he'd written

Salve umbistineum geminatum Martia proles.

or Be greeted, double knob, children of Mars. Kepler took this to mean that Galileo had observed two moons of Mars, which he (Kepler) has predicted.

But Galileo's real message had been Altissimum planetam tergeminum observavi.
Or I have observed the highest of the planets [Saturn] three-formed.

Which little story (You are not allowed to view links. Register or Login to view.) goes to show how unreliable such messages are.