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Re: [Phys-L] ? FCI --> momentum flow

Isn't the momentum of the top book upward? Due to the rigid nature of the earth and the books further down in the stack, the top book is being pushed radially outward relative to the surrounding flow of space-time. Where is the downward force?

Bob at PC

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of Jeffrey
Schnick
Sent: Friday, November 01, 2013 9:05 AM
To: Phys-L@Phys-L.org
Subject: Re: [Phys-L] ? FCI --> momentum flow

I think that to treat the momentum flow as the flow of scalar components of
momentum is a misguided attempt to simplify the concept. Momentum is a
vector quantity and a vector is more than a set of three numbers. (See
http://www.phys-l.org/archives/2013/10_2013/msg00162.html.) I ran into
the problem with this when I was talking to someone who has used Thomas
Moore's six ideas book for many years. I asked him a question of about the
upward flow of downward moment (corresponding to the gravitational
force) from the earth to the top book in the stack of books under discussion
in this thread. He didn't know what I was talking about. When he figured it
out he said that to him, the gravitational force corresponded to the
downward flow of the z-component of momentum. (He defined the z axis
of a Cartesian coordinate system to be pointing upward so he wasn't wrong
except for the fact that to him the flow in question is a flow of a scalar
quantity.) The fact that we are dealing with th e flow of a vector quantity
does make the concept more complicated than for instance, the flow of
energy, but I don't think we should model it as the flow of the three scalar
components of a vector quantity. Those scalar components are not really
even scalars in the sense that they don't transform as scalars.

-----Original Message-----
From: Phys-l [mailto:phys-l-bounces@phys-l.org] On Behalf Of John
Denker
Sent: Sunday, October 13, 2013 10:06 PM
To: Phys-L@Phys-L.org
Subject: [Phys-L] ? FCI --> momentum flow

Hi --

I have done some work on my document "introducuction to force and
momentum"
http://www.av8n.com/physics/force-intro.htm

.
.
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