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

Baynesr at comcast.net Baynesr at comcast.net
Sun Jan 30 14:27:49 EST 2011

I agree with most, if not all, that Scott says here. Let me just add one thing on 'E=MC^2'. It has many equivalents; but even if you don't "monkey" with other considerations such as introducing Plank's constant, frequency, waver length, etc. your choice of units can make it look different. So, if instead of miles per hour or kilometers you create a unit for 'C' you can see it in different ways. So, e.g., if you take the unit of 'C' to be distant traveled in one unit of time equal to 1, then the formula will come out 'E=M'. In this case, if you take 'M' to be rest mass (the natural and right thing to do) then given that a photon has no rest mass E becomes 0, right off, whence 'MC^2=0' *in this case*; in fact 'MC^2=M' (Tautologically 'M=M' iff 'E=MC^2') where M is greater than 0 and the unit for 'C' is 1). In other words, there are a lot of things you can do algebraically. 

Let me "core dump" my immediate and, so far, hidden agenda. I think that minds are not in the head; to this extent I am a Cartesian, that is, minds are like meaning (vide Putnam, Burge, et al). I think that choice and probability are very different notions and relate differently to causation. The former, not the latter, is embedded even in the mathematics concerned with distance. Choice is involved in the concept of a limit in a certain way: recall 'as close as you like' in the df. of a limit? If, for example, you use the Fundamental Theorem of Calculus to calculate the area under a function using antiderivatives, all derivatives are limits and there is an element of choice, something like choice of units. In my opinion this holds even on the now accepted definition of limits in terms of inequalities. But if you don't use the Fundamental Theorem and, for simple problems, employ a Riemann sum where no limit is involved, STILL there is an element of choice, given that you can get accuracy "as close as you like" depending on how you partition the interval over which the sum is made. So there is what I have in the past called a "norm" even in describing mathematically the laws of classical mechanics etc. I've actually barely begun to examine the role of choice in math and logic. In logic the notion of a domain of interpretation is what might be called a "choice point." I didn't want to bring this up until later. I had better defer comment until I get this clearer. 


Steve Bayne 

----- Original Message ----- 
From: "Scott Holbrook" <scott.holbrook at gmail.com> 
To: Baynesr at comcast.net 
Cc: "hist-analytic" <hist-analytic at simplelists.co.uk> 
Sent: Sunday, January 30, 2011 9:38:14 AM 
Subject: Re: Materialism and mass as a unit of measurement 

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. 


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. 

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 


"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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