Talk:Philosophy of physics/Archive 1

Archive 1

The following is clearly not an encyclopedia article, and it's barely even English:

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A philosophy of physics, should provide solution for concepts ill defined terms in the mathematical realm by modern scientists. Let us then consider some of the problems of philosophical nature established by modern physics.

1) What is the nature of space, quantic as in our observance of energy, or continuum, as in the theoretical structure called the Cartesian graph, and the theoretical structure called Relativity?

2) What is the nature of Time, continuous or discontinuous as in Biology and Phylosophy, in which species have different rhythms of time.

3) What is the nature of matter, eternally divisible or indivisible?

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This page desperately needs ot be rewritten. If I have time I'll return here the next few weeks and attempt to expand and systematize it. - Victor Gijsbers

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Some time ago, I started a very ambitious article entitled the Intellectual history of time. It is not where I would like it to be. It seems that the few people besides me that have worked on it did not understand the purpose of it, or even comprehend some of the sentences that I wrote in it.

Although the article itself is sub-par as it stands, I think it may prove useful for the section "Philosophy of Space and Time", esp, in regard to question 2 above. Essentially, the main purpose of the article was to discuss question 2 above, as sort of a genealogy or archealogy of our philosophy of time. (or an epistemology, to be more conventional and presumptious) I think my intentions were very much inline with question 2.

I mention the article (Intellectual history of time) for the purposes of whatever advantages may be procured from it in regard to Philosophy of Space and Time. Whether people want to take chunks of it, link to it, just use some concepts from it, or ignore it all together, is up to them. It might be more creatively conducive to begin construction on Philosophy of Space and Time without much regard for Intellectual history of time, and look for advantages to be procured from Intellectual history of time only after Philosophy of Space and Time has already established it's identity.

In any case, I offer it up as a potential resource for information and discussion. -Kevin Baas

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For now, let's combine the ancient and modern notions of physics for this article (i.e.: adding to this article the philosophy of natural philosophy).

Let me explain why I think we should. Physics and natural philosophy concern themselves with the understanding of the real world of change, by admittedly different methods. The philosophy of physics (both methodologies) have to do with how these real objects are studied, that is by an investigation of the procedural methods. For example, it might be noted that physics is much more mathematical than the other sciences or the way physicists derive principles from observation of oppositions in nature of various scales and qualities. Since they deal with the same object of study, the customs that have grown around investigating the physical world can be treated as either common to all physicists or as different sides to the same coin (the way philosophy or science both contribute to our knowledge of the natural world).

On the other hand, understanding the general terms which physicists use to express their conclusions, like time or space goes beyond studying reality, and while is a fact that deserves to be mentioned as what physicists acting as philosophers do to organize their science or philosophy of the real world (I have the Einstein quotation in mind here), it shouldn't be suggested that this organizational work is the proper subject matter of the philosophy of physics rather than the means of studying reality itself.

That is why I am changing the lead paragraph of this article to include not just modern physics. And why I may do other changes later to the Einstein quotation.

64.154.26.251 03:21, 24 May 2006 (UTC)

Uncertainty Principle

Schrödinger's Cat is a representation of the concept of superposition of quantum states, the Uncertainty Principle is a completely different notion. I think the reference to Schrödinger's Cat (picture) is completely misleading in this section. Benzh 23:01, 7 October 2006 (UTC)

Yes. The section on uncertainty is quite poor. It confuses the HUP with issues of superposition and collapse. The reference to "fate" is silly. More citations are needed. There should probably be a separate section on "superposition and collapse".1Z 14:27, 21 January 2007 (UTC)

The review of Physics continues at Talk:Physics/wip

Some time ago a group of editors set up a "work in progress" page (at Talk:Physics/wip) to hammer out a consensus for the Physics article, which for too long had been in an unstable state. Discussion of the lead for the article has taken a great deal of time and thousands of words. The definitional and philosophical foundations seem to cause most headaches; but progress has been made. Why not review some of the proposals for the lead material that people are putting forward, or put forward your own, or simply join the discussion? The more contributors the better, for a consensus. – Noetica 01:57, 6 November 2006 (UTC)

Update: Concrete proposals have now been put forward, arising from recent discussion aimed at producing a stable and consensual lead section for the Physics article. We have set up a straw poll, for comments on the proposals. Why not drop in at Talk:Physics/wip, and have your say? The more the better! – Noetica 22:31, 13 November 2006 (UTC)

Contemporary philosophers-of-physics.

The article gives the impression that philosophy-of-physics stopped in the 1930s. Where are David Albert, Bernard d'Espagnat, Max Jammer, Bas van Fraassen, David Wallace (physicist)?1Z 14:34, 21 January 2007 (UTC)

Sklar, Earman? —Preceding unsigned comment added by 75.28.0.246 (talk) 04:08, 20 October 2007 (UTC)

This criticism is perfectly well-taken, and I would add the names of John D. Barrow, Nick Bostrom, Katherine Brading, Harvey Brown (philosopher), John Leslie, Huw Price, Abner Shimony, and Victor Stenger. But the problem is also part of a much bigger and graver one: this entry has no references at all!!123.255.63.50 (talk) 23:54, 21 December 2008 (UTC)

Get stuck in and add those references and contribute to the article if you can. Don't leave it to the next person. Wikipedia is a collaborative effort, after all. Puzl bustr (talk) 20:57, 31 October 2009 (UTC)

Determinism

Another bad section.

"The 18th century saw many advances in the domain of science. After Newton, most scientists agreed on the presupposition that the universe is governed by (natural) laws that can be discovered and formalized by means of scientific observation and experiment. This position is known as determinism."

Indeterministic laws are laws too.

"However, while determinism was the fundamental presupposition of post-Newtonian physics, it quickly lead philosophers to a tremendous problem: if the universe, and thus the entire world is governed by natural law, then that means that human beings are also governed by natural law in their own actions. In other words, it means that there is no such thing as human freedom."

Many contemporary philosophers think determinism is compatible with freedom.

"If it is accepted that everything in the world is governed by natural law, then we must also accept that it is not possible for us to will our own actions as free individuals; rather, they must be determined by universal laws of nature".

Again, a confusion between "governed by laws" and "governed by deterministic laws".

"Conversely, if it is accepted that human beings do have free will, then we must accept that the world is not entirely governed by natural law. However, if the world is not entirely governed by natural law, then the task of science is rendered impossible: if the task of science is to discover and formalize the laws of nature, then what task is left for science if it has been decided that nature is not entirely governed by laws?

The answer is to find out how it is partially governed by laws - -to find out the probabilities and stochastic rules. Physics continues and most physicists accept indeterminism, so indterminstic physics is not an impossibility.

Thus, there are extremely compelling reasons to want to accept both free will and determinism. However, the two seem totally irreconcilable".

Not according to compatibilists.1Z 14:51, 21 January 2007 (UTC)

The Determinism section should probably be completely scrapped. Free-will isn't really a big topic in philosophy of physics. It's discussed in other sub-disciplines of philosophy. The idea that there is </>any relationship between QM and free-will is a marginal position, as far as I can tell. —Preceding unsigned comment added by 75.28.0.246 (talk) 04:12, 20 October 2007 (UTC)

Atomism

Atomism? I cannot remember ever coming across a reference to atomism in a phil physics context. Maybe somebody knows something I don't know. But I suspect that atomism should be taken out. Space, time, quantum mechanics, causation/laws; these are the central topics as far as I can tell. By the way, it looks much better than it did a month ago. Good job! 75.13.202.239 07:24, 10 November 2007 (UTC)

Logicist writer?

From the section titled "Mathematical nature of physics": "Because mathematics is simply a formal logics, it can deduce..." and "Philosophy of physics is very close to the philosophy of mathematics (which is just logic)" I do not know much about maths, logic, physics or philosophy of physics, but this seems to be written by a defender of the logicist program, wich is sometimes described as abandoned. Am I right? Could somebody with just a little more information confirm this and change it? Thank you. LFS 02:55, 21 February 2008 (UTC)

Whether or not this is termed logicist, almost everything in this paragraph seems demonstrably wrong. Mathematics is not reducible to logic. Mathematics cannot be used to derive the truths of physics without reference to experiment. Philosophy of physics has almost nothing in common with the philosophy of mathematics. I have no idea what "deep parallels" between mathematical axioms and physical theories are being referred to. If no one posts an objection I'm going to delete this paragraph. Thirdtorpid (talk) 00:12, 28 August 2008 (UTC)

Good plan!P0M (talk) 01:30, 28 August 2008 (UTC)

Logicism died when logicians and philosophers agreed that mathematics requires set theory, and that set theory is more than logic (it requires extralogical primitives, ontological assumptions, and axioms). Some authors, like Roger Penrose in his The Road to Reality, write as if mathematical logic and set theory may shed some light on the foundations of physics. Plato and his followers indulged in such speculation, but it still remains, in my view, highly conjectural at best.

There have been attempts to recast mechanics, thermodynamics, and special relativity, as axiomatic theories. Some work of this nature is summarized in the Appendix to Rudolf Carnap's 1958 logic text. While recasting parts of physics as axiomatic theories may clarify physical theory and make its exposition more elegant, it is my strong impression that working physicists have taken very little interest in such work. Incidentally, if there is one thing that drives a big wedge between pure mathematics and physical theory, it is the dimensionless physical constants. Also see Martin Rees's 6 fundamental numbers. These constants are baldly empirical; hence it is impossible to ground physics in pure mathematics or logic.123.255.63.50 (talk) 22:52, 21 December 2008 (UTC)

A recent comment

The sentence in the paragraph Time about the idea that time has begun 13.7 billion years ago is clearly wrong. Current cosmology does not suggest that the universe started 13.7 billion years ago. Apart from that the idea that time could be said to begin is clearly wrong (with what could time have begun, since without time there can not be change). Heusdens (talk) 00:42, 12 July 2008 (UTC)

New material should be added at the end of the page, not put up on top.

If you have a reputable source that dates the universe at a different age, bring it forward.

The philosophical argument that you offer has been examined by scholars since the earliest times of human philosophy. Kant brought out clearly the idea that there are two equally powerful logical arguments,one saying that the universe is eternal and one saying that the universe has a beginning, and neither can refute the other. Medieval Christian philosophers argued that space and time were created by God and therefore have a beginning.

When the science of astronomy gained adequate instrumentation astronomers concluded that every celestial object is moving away from every other celestial object, the inevitable result being that the universe is expanding. If we "play this movie in reverse" it looks at though the universe could have come into existence from a single point in space and time. That understanding of the universe, derived from empirical scientific knowledge, supports the medieval Christian view that space and time were created "in the beginning."

Science being the open-ended pursuit of refutation of its own theories, the winnowing out of models that do not work well enough, it is always possible that the idea of the Big Bang will end up in the trash. But at present it is a well-accepted theory. The current age of the universe is an estimate at best since nobody turned on a cosmic egg timer at the dawn of creation. It is more likely that later views on the age of the universe will differ from the majority view of the present. P0M (talk) 03:10, 12 July 2008 (UTC)

Removed Schrodinger's Cat image

As noted above, Schrodinger's cat is a thought-experiment concerned with quantum superposition of states. Here the superposition is of the states cat alive and cat dead. Whilst interesting, this is not an illustration of the uncertainty principle, so I removed the picture. Puzl bustr (talk) 11:08, 31 October 2009 (UTC)

Uncertainty Principle

Cleaned up this section taking into account criticisms above. Removed the reference to fate, re-phrased discussion of Copenhagen interpretation so more coherent. Added a ref taken from the main article. Indicated need for more references. Removed last unreferenced paragraph. Not sure what "the probabilities" refers to, and without references unclear how to interpret it. There are many probabilities in quantum theory. Not sure in what sense they are "fundamental". Perhaps this paragraph could be expanded to be clearer, and given a reference. Puzl bustr (talk) 21:19, 31 October 2009 (UTC)

Pluralism

Under See Also, you have a link to Pluralism, which is a disambiguation page. There are various forms of pluralism mentioned on that page that you may consider as relevant to the Philosophy of Physics. Escapepea (talk) 22:04, 23 January 2011 (UTC)

Determinism and quantum mechanics

AFAIK quantum mechanics doesn't actually rule out determinism: if you knew the wavefunction of the entire universe at time t=0, then, by simply applying the time evolution operator to its eigenstates would allow you to know the wavefunction at all times t. Only measurement of the wavefunction causes it to collapse, but even here the only reason for wavefunction collapse is that quantum variables are being measured by a necessarily classical method. Wavefunctions don't collapse when "measured" by another quantum system, and since the whole universe is quantum, collapse never really occurs. Should the article include this or is this too technical and belongs somewhere more obscure? — Preceding unsigned comment added by 92.27.55.215 (talk) 16:38, 21 May 2012 (UTC)