[Dragaera] Fwd: Moon(s) and Tides (was Re: Jhegaala etc.)

[Rebecca Harbison]

On Jul 18, 2008, at 11:18 AM, Jon Lincicum wrote:

> Matthew Jennings wrote:
>> Conspicious by its absence: a moon.  Is the Dragaeran 'planet'  
>> moonless? Did
>> we already know this. Would have been handy for Vlad.
>>
> In /Phoenix/, Vlad talks about the winds and tides when going to  
> Greenare. Tides means moon. QED.
>
> It is somewhat curious that we do not see mention of it. But then,  
> perhaps it is a much smaller moon, or it was a new moon during the  
> two or three days he's in town stirring up trouble before he's...  
> inconvenienced, and not in a position to notice anymore.  
> Alternatively, perhaps the moon is composed of dark matter and not  
> visible at all?

The Sun (at least on Earth), also produces tides -- they make up  
about a third of the strength of the total tide on Earth.  Assuming  
normal gravity, if a planet orbited a sunlike star and had no  
satellite, the tides would be weaker than Earth's, and happen at  
about the same time every day (high tide around midday and midnight,  
low tide around dawn and dusk), but they would be present.  They also  
would be nearly constant in strength at the same location -- local  
places might have stronger effects depending on the shape of the sea  
bottom (as, I'm sure, any sailor could tell), but there wouldn't be a  
strong spring tide and a weak neap tide over the month.

I'd have to reread that part in /Phoenix/ to see if the tides could  
still fit with only the Furnace in the sky.  If they change in  
strength over the month, or occur at different times, then it implies  
a moon or moons.  (You could also get the rough phase of the moon  
from the tides).

-- Rebecca (Becca Stareyes)