[cap-talk] Authority vs. Information Flow

[Charles Landau]

At 4:19 PM +0000 2/13/08, Toby Murray wrote:
>The question is "If Alice has authority over Bob,
>does it follow that there exists an information flow from Alice to Bob?"

If Alice has read authority over Bob, the information flow is only in 
the other direction.

>Example 2: In which Authority exists, but perhaps not Info Flow
>---------------------------------------------------------------
>
>Now imagine the same scenario, except that now there is a third party,
>Dave. Dave also has a button like Alice, that turns on the light in
>Bob's room when it is pressed. Both Alice and Dave now have control over
>the light.
>
>We presume further, that Bob's behaviour is fully specified and does not
>permit the possibility that Bob

I think you mean Dave.

>will refuse to push his button if Alice
>hasn't already pushed hers. We make a symmetric assumption for Alice.
>Whoever pushes their button first, then, causes the light to turn on.
>
>Both Alice and Dave now have authority to cause Bob to be able to see
>the light turn on. But can either of them pass information to Bob?

There are techniques for passing information through noisy channels. 
If you consider Alice to be the signal and Dave the noise, it should 
still be possible to pass information in this case.