Re: Proof of Law of Conservation of Mass?
The TimeLord
in eb998284-0aa9-4447...@i24g2000prf.googlegroups.com in
sci.physics.relativity:
> What is the proof the Mass is always conserved?
That comes from the continuity equation:
diff(rho,t) + div(rho*v) = 0
where rho = mass density at a point
and v = velocity vector of mass at that point
and t = time
For a complete derivation of this equation see "Mechanics; 3rd ed"
by Keith Symon; Addison-Wesley Publishing; ISBN=0-201-07392-7;
pages 313-320.
[...]
> People say Quantum effect a mass can travel to another time domain.
I've never heard of that, even though, strictly speaking, it's not
ruled out by physics as it is presently understood. It's just that
nobody has ever figured out how to do it.
>
> People say time travel is possible. Then the mass which vanishes from
> our time. that is gone for ever. Then Mass is not conserved?
Actually it is conserved. I'm not permitted to reproduce Symon's
discussion here (besides, it' kinda long), but you can get access
to the book at any good library. Suffice to say that you can imagine
the conservation of mass law to apply to any closed system, for
example a box. If no mass flows into or out of the box, then the mass
inside is conserved even though it can flow around in the box. If a
mass were to be able to time-travel, then the "box" would be both the
origin and the destination of the path of time-travel. The mass of
both the past and the present would be included in this "box".
Note that this does not prove that time-travel is possible. It simply
means that *if* time-travel were possible, that is how you would have
to conceive of conservation of mass.
>
> I am new to this topic, so speak in simple language.
No problem. - BTW, I'm redirecting this thread to alt.sci.time-travel
since that is where this issue is routinely discussed.
--
// The TimeLord says:
// Pogo 2.0 = We have met the aliens, and they are us!
Pmb
"The TimeLord" <math-n-ph...@att.com> wrote in message
news:1fydndyvsc_6SSvV...@comcast.com...
> Am Thu, 28 Aug 2008 08:44:50 -0700 schrieb Sanny <soft...@hotmail.com>
> in eb998284-0aa9-4447...@i24g2000prf.googlegroups.com in
> sci.physics.relativity:
>
>> What is the proof the Mass is always conserved?
>
> That comes from the continuity equation:
>
> diff(rho,t) + div(rho*v) = 0
Actually the continuity equation is derived based on the conservation of
mass.
Pete
The TimeLord
in UIadnSW0NsiRTCfV...@comcast.com:
Actually it's the other way around: the conservation of mass comes from
the continuity equation with rho*div(v)=0 hence the right side is zero.
For a complete derivation of this equation see "Mechanics; 3rd ed"
by Keith Symon; Addison-Wesley Publishing; ISBN=0-201-07392-7;
pages 313-320.
--