Physical Laws and Change Having Separate Ground?
Posted by Tanas Gjorgoski on February 2, 2007
Physics can provide to us reasons of why some measurements of a system at some time t2 give such and such results, by appeal to:
- A physical law PL
- Results of measurements of the system, at some earlier time t1.
The PL in this picture (I will say later why this is simplified picture) tells us about a necessary relation (necessary in our world) between these and those potential quantifications of universals which can be abstracted from the system (quantification being connected to measurement as both number and measurement are in a form of a ratio; and measurement being abstraction as it requires focusing on one specific aspect of the system while ignoring the others). By having: a)the times t1 and t2 (also quantified somehow), and b)the measurements in t1, one can easily explain measurements in t2.
Simple analogy would be this… If the relation x=2*y holds between x and y, one can explain x being 4, by both the appeal to that relation and to y being 2. (We ignore here why it is the value of x that is in need of explanation, or why do we believe that the relation holds, or that y is 2)
The picture presented is oversimplified as:
- In some cases like in Quantum Mechanics, physical laws doesn’t provide sufficient reason (I discussed this in greater length here) why the measurements at t2 are such as they are. (so called measurement problem)
- The physical laws are usually not given as a relation between ‘potential measured values of universals’, but are in differential form.
Let’s ignore those issues here, even they are very interesting (hope I will write about them in some later post), and also let’s ignore the reasons why we believe that the PL actually holds. Let’s assume that it is true that PL actually holds.
Having put all those things aside, I want to put forward following idea:
Because of the presence of the quantified universal of time in the physical laws, we tend to assume that physical laws are the cause of the change in the universe, or that whatever is cause of those physical laws is also the cause of the change in the world. That is – that the physical laws , or their cause is the reason why the universe changes. I think that we don’t have reason to think that this assumption necessarily holds.
To start with I want to point to conclusions of previous arguments that:
a)time is abstraction from change and
b)as far as it is quantified it appears as a ratio between the duration of some change, and duration of some other change (or process) taken as unit.
CT: As such, we shouldn’t imagine time as some self-subsistent notion (idea of absolute time), which will be there as some kind of form (in Kantian or some other sense) even if we remove anything more concrete (namely notion of things undergoing changes). Instead, the time should be seen as yet another potentially quantified universal within the law, on same level with other universals (e.g. position, energy, mass, momentum).
But when we reduce the “time” to yet another abstraction showing up in the physical law, the relation stated in the physical law now appears in the same form as some necessary relations appeared in the cases of a priori relations which were analyzed in previous few posts (The Trivial Case Of The Strawberry Seeds ,Familiar Faces, Gestalts and A Priori Truths).
In those posts I argued that we have understanding of a relation that holds a priori, if in our thinking we comprehend that any concrete C that falls under universal U1, will also fall under universal U2 – where the identity lays not in some “external” relation between universals, but in the concrete, and possibility to recognize that as far as the concrete falls under U1, it will also fall under U2. But, in those cases, it is clear that this identity of the universals isn’t something which constitutes the concrete – that 2 is 1+1, or that square with sides 2x contains 4 squares with sides x, doesn’t at all determine the concrete. The relation holds for lot of different concretes as long as they fall under the universal “two” or under universal of “square with sides 2x”. Such relations between universals don’t in the least affect the concrete! The reason why the necessary relation between universal holds is logical or mathematical reason, the thing is totally unaware that it can be put under these or those different universals. (Are four marbles affected at all by the fact that they can be seen as four things, or two pairs, or one quartet, or rolling things with 4/3*pi*r^3* volume, etc…?)
I think that the situation is not different (at least in the form) in case of physical laws. That in the case of physical laws, we have the notion of time also related to other notions doesn’t make any difference because of the reason CT already pointed to – what is needed is just to acknowledge that the notion of persistent thing undergoing changes is seen as more concrete (more concrete then a notion of “thing X at time t”), and we again have a concrete on one side, and the necessary relation between universals which can be abstracted from the concrete on the other. Same as in the case with a priori truths, the relation between universals is such that should hold necessary (though in this case, it is not clear if it is metaphysically necessary). But also as in the case of the a priori truths those necessary relations between those universals might not in the least affect the thing.
In such way, the reason why the physical law holds, might not be at same with the reason why things change.
Anyway, this is just a sketchy idea, I hope I will have better argument in future. Also I think it is interesting to think more about a thing I ignored here – that the physical laws are usually in differential form. It wouldn’t be surprising that analysis of their differential form might show them as more tightly connected to the reason of the change of the things.
This entry was posted on February 2, 2007 at 7:52 pm and is filed under Metaphysics, Philosophy, Physics. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.