[hist-analytic] Materialism and mass as a unit of measurement

Scott Holbrook scott.holbrook at gmail.com
Sun Jan 30 10:38:14 EST 2011


This is all pretty interesting and a lot of it still hasn't really been
decided by physicists.  But I think we can side-step most of it.

First, I would just like to point out that E=mc^2 isn't really the whole
equation.  The whole equation is:

E=sqrt((pc)^2 + (mc^2)^2)  ; where p="rest mass" x "speed of light"

But, since photons are never at rest, they never have "rest mass," it just
doesn't make any more sense that "round squares."  (This term is actually
just an unfortunate relic from science of yester-years particle vs. wave
debate.  It was figured that if light had a massive particle component, then
there should be longitudinal waves, but there aren't.  The smaller the mass,
the harder the waves would be to detect and no longitudinal waves have ever
been discovered.  So, if there were a particle, it'd have to be
"massless.").  So, "zero rest mass" really just means "never at rest."

If that's unsatisfying, then it should be remembered that there is a
conversion factor to go between "rest mass" and "relativistic mass."  So, it
depends on what you mean by "the same units," whether or not they are so the
same.  But it should also be kept in mind that E=mc^2 is a conversion as
well.  So any ambiguity in the units on the rhs quantity would be in the lhs
as well.

Confessedly, and as Steve pointed out to me, it's not really clear what
exactly the comment on units amounts to.  I was actually interested in units
in my younger days, but physicists tend not to be bothered with such things
and I didn't know any philosophers at the time, so it just sort faded into
the background.

I think I'd like to add one more interesting comment regarding physics and
ontology.  The Bose-Einstein Condensate was speculated upon by Einstein on
account of a mathematical oddity in B-E Statistics...namely division by 0.
 So, this is a pretty glaring example of...tension?...between what the math
can describe (legally) and what physically obtains.  According to math,
zeros in denominators don't happen...in nature, B-E condensates do happen.

So, it almost seems like a real physical thing (the condensate) has no
mathematical expression...or at least not one that is allowed by
mathematicians.

Scott

P.S.  I think I'll give Jammer's book a read then jump back into the foray.
 (*Concepts of Mass in Contemporary Physics and Philosophy* (Princeton,
2000))

On Sat, Jan 29, 2011 at 4:19 AM, <Baynesr at comcast.net> wrote:

>
> "...physicalism...concerns the ontology of the world. It claims that the
> content of the world is wholly exhausted by matter. Material things are all
> the things there are." (Kim [2005] 150)
>
> Now consider an argument proposed by Block and Stalnaker as described by
> Kim.
>
>
> Neurophysiology
> Neural State N1 causes neural state N2
> Pain = N1
> Sense of distress = N2
> Therefore, pain causes a sense of distress.
>
> Note the identities. They play no real role in the explanation on Kim's
> account. He remarks:
>
> "True, these identities do have a role in the derivation of 'Pain causes
> distres,' but this is not an explanatory derivation; rather, it is a
> dervivation in which 'equals for equals'." (Kim [2005] p. 146. Elsewhere,
> and repeatedly, he describes identities as "rewrite rules." But is this
> correct? Suppose it is. If so, the Block-Stalnaker case of explanation
> appears to fall short. Suppose on Block-Stalnaker all that exists is matter,
> although we could reconstruct the argument I will propose as directed agains
> Kim, alone.
>
> Kim is, definitely, committed to two things. First, that matter and matter
> alone exists; and second, matter provides the subvenient basis for
> supervenience. Physicalists like to get technical with dualists,
> particularly when "peddling" their physicalism. Let's see how literal their
> "materialism" actually is.
>
> We are told that only matter exists. Well, what about a beam of light? It
> has no mass, and so we might want to say that it is not physical. Is this
> right? More importantly is the sense in which it is right consistent with
> Block-Stalnaker on the role of identity statements? I think not. Suppose we
> begin by saying
>
> 1. A photon is massless
>
> This is a given of physics. Another given of physics is the momentum of a
> photon can be expressed this way, where 'P' is momentum:
>
> 2. P = E/C (where 'C' is the speed of light; and 'E' is (rest) energy)
>
> Now we, also, have it as a given that
>
> 3. E = MC^2 (Yippee!) And so, from (2) and (3) we get
>
> 4. P = MC^2/C
>
> Leaving us with
>
> 5. P = MC
>
> But wait! Doesn't (5) contradict (1), since 'M' means 'mass'? David
> Susskind once raised the question whether the "units" associated with the
> momentum of a photon are the same as those for massed particles
>
> 6. P = MV (for picky people assume we are dealing with vector properties
> where applicable).
>
> That is: does 'M' in both (5) and (6) get indicated by the same units of
> measure? He sees no problem. I do, one brought on by accepting
> Block-Stalnaker. If we suppose that these identities are "rewrite rules"
> then there is no force to the claim that the identity is ontological; it
> becomes a matter of choice of convention. But if this is so, then neither
> Block-Stalnaker nor Kim's materialism can be sustained as a ontological
> claim, particularly in the case of things like photons. By the way, Kim has
> not committed to "ontological relativity." The photon is interesting in
> another way relevant to discussions of physicalism.
>
> I am concerned with Kim's belief that subvenient bases of supervient
> properties must be material. Here we have a massless oscillatory field
> phenomenon consisting of two waves wedded in geometrical symmetry: the
> magnetic wave at a 90 degree angle to the electric. Now these two are not
> identical. First, either the magnetic or the electrical properties of the
> beam of light satisfies being the subvenient basis of the other; so we
> appear to have mutual supervenience in the absence of a material subvenient
> base. I would add, as an interesting aside, that we have here a symmetry
> dependent periodicity which will become significant as I examine issues
> raised by Mele's discussion and dualism generally.
>
> The main point: we cannot use Block-Stalnaker identities in explanation
> since they allow idntifying a photon as possessing mass. Once we isolate the
> sense in which this IS allowed we forfeit the idea that explanation can be
> transferred from talk of one thing, such as c-fibers to another, pain.
>
> I haven't edited this darn thing. I may revise it as I usually do pending a
> reread at some point.
>
> Steven Bayne
>
>
>
>
>
>
>
> 45000




-- 
"Conventional people are roused to fury by departures from convention,
largely because they regard such departures as a criticism of themselves."
-- Bertrand Russell

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