Floo/head-in-the-fireplace, was Re: OK, The Portkey

[snazzzybird]

No: HPFGUIDX 57609

--- In HPforGrownups at yahoogroups.com, "Amanda Geist" <editor at t...> 
wrote:
> <Much snippage of a well-thought-out discussion of Floo powder and 
head-in-the-fireplace communication> 
> 
> As for whether Floo is the mechanism for the head-in-the-fireplace
> communication--I think it is. I don't think it is such a stretch to 
go from
> sending your voice by Floo, which I think canon supports, to 
someone, to
> sticking your head in the fire to talk to them directly.
> 
> For the Snape/Lupin interaction, I think that Snape could have 
stuck just
> his head in the fireplace to ask Lupin directly...
<snip>

Now comes snazzzybird to say -- 

I'm so glad to see this topic brought up!  I've meant to bring it up 
myself, but somehow the time never seemed right.  I have been 
extremely curious about head-in-the-fireplace communication (which I 
will hereafter abbreviate to HITF).  In fact, one thing I'm hoping to 
see in OoP is the "initiating" end of such a conversation.

We know that the sender can look all around the receiver's room, as 
though he were physically in that room.  We know that the flames that 
surround his head are harmless to him.  However, the receiver has no 
such protection: remember, Mrs. Weasley used an implement to give 
Amos Diggory the toast; she didn't just reach into the fire.

We know what this conversation looks like from an observer at the 
receiving end.  What does an observer on the sending end see?  Is the 
person who initiated the call on his hands and knees before the 
fireplace, with his head in the flames?  Is his head visible to the 
observer?  If so, does it look to the observer as though the person 
just has his head in the fireplace -- or can he see, dimly through 
the flames, the room at the receiving end?  (I'm thinking of a 
telephone conversation, in which the people on the phone can hear 
ambient noises in each other's homes, and if the telephoners speak 
loudly enough, other people in the room can hear the voice coming out 
of the handset.)

Does this communication only work if there's a fire in the other 
person's fireplace -- or does an incoming HITF communication cause a 
magical fire to ignite there?  What happens if someone tries to Floo 
in at the time there's a HITF?  What if (say) Arthur Weasley tries to 
call home, but Mrs. Figg's head is already in the fireplace?  Does he 
get a busy signal?  Or is there such a thing as three-way HITF???

Okay, now I'm getting silly... but I'm serious about wanting to know 
how it works.  What do you think?

--snazzzybird, who promises not to even bring up Caller ID.