[extropy-chat] still no biscuit!

[Eliezer Yudkowsky]

Damien Broderick wrote:
> At 03:24 PM 1/19/2005 -0500, Eliezer wrote:
> 
>> the hypothesis of conservation of momentum is not that momentum is 
>> conserved 90% of the time or even 99.9999% of the time.  The 
>> hypothesis of conservation of momentum is that momentum is conserved 
>> 100.00000% of the time.  We may be uncertain, but the hypothesis of 
>> "conservation of momentum" hypothesizes a state of affairs in which 
>> reality is *not* uncertain; a reality in which it is *absolutely 
>> certain* that momentum will be conserved on each and every occasion.
> 
> It's true that physicists thought so 100 years ago. Then they found that 
> with the conjugate properties position and momentum, 100% accuracy in 
> measuring position meant momentum went all over the ship. Bugger, eh?
> 
> Granted, `reality' as Eliezer is using it refers to immense ensembles of 
> individually uncertain events, so that by and large observed macroscopic 
> momentum is pretty robust, even if its substrate is only statistical. 
> But let's not go all 19th century on Brett's ass.

I don't understand exactly why, but I was under the impression that 
conservation of momentum remains exact.  Do any local physicists care to 
speak up?

-- 
Eliezer S. Yudkowsky                          http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence