Showing posts with label Aristotle. Show all posts
Showing posts with label Aristotle. Show all posts

13 May 2015

Non-emergence?

According to Robert Laughlin Nobel Prize winner physicist, Newton’s “fundamental laws” aren’t fundamental at all, since their rise is “a consequence of the aggregation  of quantum matter into macroscopic fluids and solids—a collective  organizational phenomenon.” [Laughlin: A Different Universe, p. 31.] So perhaps we can build up a physics based on the idea of emergence, and it is at least questionable whether either the fundamental laws or the fundamental constants remain important after reinterpreting this field.
It is undoubtedly an interesting idea, and I don’t have any problem with the approach of a new interpretation of nature. But I have some problems with this emergent approach.
First of all, why do we presuppose that the laws of the quantum level is more fundamental than the level of Newtonian physics? Because is it about a smaller magnitude?
Second of all, the use of the term of the emergence is sometimes resembles for the “God of the gasp”: Certain theologians interpret the gaps in actual scientific knowledge as a proof of the existence of the Lord. The classical example for the emergence is the ant hill, and I don’t think that the emergent interpretation is false in this case. But notice that the emergent approach offers an answer for the strangeness of a certain phenomenon (i.e. organized ant behavior), and, at the same time, it contains a tacit an assumption.
The “normal” scientific way is to observe a natural processes and then, by using induction, we deduce the natural law which resulted the given process. The emergent approach is different: we hypothesize that not some describable laws (that are descriptions of the rules) cause the phenomenon, but the phenomenon causes the effect. But, ad absurdum, it is possible that although there is a natural law to determine the organization of the ant society, having been unable to point out it, we would declare that this process’ nature is emergent. If Newton’s laws would be unknown, then we could state with conviction that the moves of the planets in the Solar System are emergent: We observe the process, and then we conclude that the process itself causes the phenomenon. Ad analogiam: how could we sure that there isn’t a law to describe the connections between the micro- and macroscopic level in Laughlin’s example?
Of course, there are emergent processes: I.e. Wolfram in his New Kind of Science presents examples where a process is uncompressible. But there are fundamental differences between math where, optimally, we can prove whether something is impossible, and physics where a similar demonstration is more problematic.
And there are other questions, as well. The dichotomy of “laws” and “objects” comes from Aristotle: He believed that on the one hand, there is a category of “natural things, which displayed change and complexity”, and there are “static and absolute truths” that are mathematical rules. [Barrow: World within World, p. 39.] Obviously, it is a kind of Pythagorean belief about the fundamentally mathematical nature of the Universe.
But it is an important question whether both the laws and objects really exist, as it is believed by the so-called realist philosophers of science. Opposite to it, the instrumentalists state that the physical laws are only instruments to describe the observed processes but they aren’t exist in reality.
It is undecidable which camp is right, since there is no an experiment to point out whether a natural law really exists or it is only a mathematical description. In short: it is pointless to debate over it.
Similarly, it is undecidable whether the individual ants’ behavior emerge into a coordinated activity to cause the anthill or the rules behind the operation of the colony drives the individuals.

31 March 2015

The origin of the multiverse

According to Aristotle our world which had a potentially infinite past and it’s spatially extension was finite, but a potentially infinite past is unacceptable today, since it necessarily ends in our present. So it is completed – and so it cannot be potential (but a potentially infinite future is still a possibility). Obviously, Aristotle’s finite space conception is similarly contradictory for us, as it is based on the belief in a finite, spherical shell of the stars that surrounds the Universe.
Newton believed in actually infinite space and finite time – namely, according to him the World was created some thousand years ago (of course, if we do not accept the existence of a final point in history, then it has a potentially infinite future).
The Big Bang Theory uses a finite spacetime model.
Last but not least, according to a common interpretation, the multiverse hypothesis presumes that both space and time is actually infinite and the Big Bang is only a bubble in the infinite sea of other bubbles. This resembles to the Steady State Theory, since it declares a spatiotemporal infinity without a beginning (and it is ironic that this obsolete model, which is forgotten in traditional cosmology, survives in this form). As far as I know, nobody examined the question of the possible origin of the multiverse as a scientific problem. Of course, if you believe that it has no origin (since it is spatiotemporally infinite), then it is a meaningless question.
But we can play either with the idea of a spatiotemporally finite multiverse that includes  only finitely many universes.The fact that we cannot able observe other worlds, does not mean that there are infinitely many of them.
Or there is a possible multiverse model where time is finite (or potentially infinite), but its space is actually infinite. In other words: it is a multiverse that was born a finite time ago but it is spatially infinite since the beginning, and it resembles to Newton’s model in a certain way. The appearance of infinity is always problematic in physics, so – at least from this point of view – this model with an instant spatially infinity is not more contradictory than the traditional multiverse interpretation with an infinite past.

08 March 2015

The nature of the natural laws

Although both the existence and the nature of physical laws usually are taken for granted, it is worth examining these ideas’ origin, since it can influence even the approach of today’s science.
Aristotle developed a rather complicated idea about the causes (ending with a kind of “Formal Cause” – which “causes” the form). His “Final Cause” became the modern laws of nature and his “Efficient Cause” is close to modern cause (Barrow: World within World, p. 53). So following Aristotle’s logic we make a distinction between the laws and those phenomena they affect. But it is not surely a necessary distinction between causes and their subjects. The fundamental question is whether the laws exist in a certain sense or they are only practical descriptions of reality. According to Lee Smolin, supposing a kind of cosmic evolution and the existence of baby universes that are born with slightly modified natural laws than of their parent universe's, this “evolving laws seems to be a breakdown of the distinction between the state of a system and the law that evolves it.”
This hypothesis makes possible to imagine some different scenarios between the laws and those subjects that are affected by them.
1.
Obviously, we can accept the traditional laws vs systems differentiation.
2. But it is more exciting to suppose that the formation of a baby universe means the formation (slightly) different laws. It can be happened three different ways.
  • The first one means that the law formation is restricted to the moment of creation (whatever it means). After the Big Bang we have a certain amount of matter, energy etc. and it won’t change. Similarly, the laws are “finished” as well and they won’t change. On the other hand, Smolin supposes that different universes can be determined by different laws.
  • But why to restrict the changes of natural laws for a very short period of time? A second solution proposes a longer, even continuous evolutionary process where the forming laws and the physical environment are in continuous interaction in the course of the universe’s history. According to this model, not only the initial laws of a new universe are different from its parent’s laws, but the changes can be influenced by some events in the history of the universe and slightly different initial conditions would result very different laws later.
  • To make the story even stranger, there is the problem of the saltation hypothesis. In evolutionary theory not accepted to suppose that biological evolution produces its effects via large and sudden changes, but cosmology isn’t about earthly ecosystems’ biology. The laws of our Universe seems to be fixed today, but it is imaginable that this idle period when our physical laws are static is only a transitional state, and then a sudden saltation would happen in the future and the nature of the laws will radically change.

17 February 2015

How (not) to avoid the G-world in cosmology?

The first chapter’s title in Mary – Jane Rubinstein’s recently published book entitled Worlds Without End. The Many Lives of the Multiverse is: How to Avoid the G-word.
Namely, the God.
It is an interesting trend that not trying to avoid the G-word is an acceptable attitude for some modern cosmologist, although the Creator’s existence or non-existence hasn't play a role in modern optics or mechanics (what is more, it is not a question in the explanation
At the beginning of the 17th century Galileo argued that there were two books written by God. One of them was the the Bible and another was the book of nature. Although it was a common belief of that age that both of them used the same language, according to Galileo, the second one used the language of mathematics. [John Hedley Brooke: Science and Religion, p. 104] Supposing the existence of a Creator who created the World for humans, it is an open question why He had decided to use two different languages, and why an exotic and complicated system was introduced to describe the physical reality created by Him. In other words: why the physical reality is so complicated that it is impossible to describe it in everyday words? Was it a necessity to hide the structure of the world behind a complicated and non-evident formulism?
Obviously, Galileo’s concept based on a kind of Neoplatonic mathematical mysticism. According to it, the fundamental structure of our Universe is not only can be described by mathematics, but the nature itself is purely mathematical. But it is not an answer for the question why decided God to choose this language.
On the other hand, a group of physicists in the 17th century refused the Aristotelian concept which stated that an explanation cannot be complete without pointing out a final cause. Since Aristotle didn’t favor mathematics as a language of world description, Galileo’s approach offered a way to deny any argumentation based on final cause, and Descartes decided to focus on immediate causes of physical events. [Brooke, ibid, p. 72]
Since then it became a tradition in natural sciences to study those immediate causes and omitting either a final cause or the intervention of a Creator. But – to oversimplify the problem – when somebody studies either the “fine-tuned” nature of our Universe or the supposed existence of multiverses, there isn't an opportunity to study his or her subject from Descartes’ approach, because there is no an existing physical event to examine.
According to Bernard Carr, “If you don’t want God, you would better have a multiverse.” Namely: if you don’t want to refer to God, then you can replace Him with the idea of Multiverse – or vice versa. The “Multiverse replaces God with what is perhaps an equally baffling article of faith: the actual existence of an infinite number of worlds.” [Rubinstein, p. 29]
We have two different strategies to handle the causes. One can choose Descartes’ approach to always focus on immediate ones – and then he or she can ask another question about the solved problem’s immediate cause. We can move forward step by step – its mathematical analogy is the potential infinity where every piece of the result is finite and it can be achieved in a finite number of steps, but this process never has an endpoint.
The other approach is more problematic. If we are allowed to ask for a not immediate cause, then we could ask what caused that cause, etc. [Rubinstein, p. 21] and the result is an infinite regress without end.

30 January 2015

The short history of the maximum speed

“Nature abhors a vacuum” says Aristotle. His argumentation based on the presupposition that in complete void there would not have any resistance to slow down a body’s motion, so its speed would be actually infinite – although he was convinced that only potential, but not actual infinite exists.
Newton represents another extremity using the idea of an instantaneous “action at a distance”. According to his theory, gravitation can act instantly even from infinite distance. Newton “left to… [his] readers” to decide whether that agent caused gravity was “material or immaterial.” [Newton: letters to Bentley] This “action at a distance” was regarded to be too mysterious and too similar to the magical forces to his contemporaries, but thanks to Laplace’s, Lagrange’s and others’ interpretation of physics as a pure mathematical description the problem seemed to be vanish [Roland Omnés: Quantum Philosophy 1999, p. 35].
Einstein’s world different from his forerunners’. Newton believed in absolute space and absolute time – they functioned as the base of a reference system and motion happened relative to it.
Opposite to this interpretation, Einstein voted for the speed of light as the maximum speed of anything can reach in our Universe, and it was absolute to any inertial frame of reference. Thus neither space nor time, but this constant (speed of light) was absolute as a barrier. It was a solution for the result of the Michelson – Morley experiment which originally aimed to verify the existence of ether as the medium of light waves, but it was a failure (notice that even Maxwell’s equation based on his confidence in the existence of ether [Omnés, p. 44]).
Einstein’s model is surely more counterintuitive than Aristotle’s or Newton’s (and it is not an accident that this appeared finally). On the other hand, it is surprisingly simple: there is no a body with mas which can reach the speed of light; and a particle with zero rest mass moves with the speed of light. That’s all. Notice that Einstein’s solution is instrumentalist in a certain sense, since it doesn’t explain why the speed of light is so special – it simply accepts its absoluteness. An instrumentalist approach can results a working model (see the Ptolemaic worldview), but it is not connected to the physical reality, since its subject is not the real world, but only a description of the real world. This means that it can be proven false at any time (as it happened in Ptolemy’s case).
There are some possible scenarios at this point.
We can believe that Einstein’s model is flawless. Obviously, it is the simplest solution. Although it is true that all the previous models proved to be incorrect, it is not a necessity that this theory will be proven to be false. Similarly, we cannot be sure that because it seemingly immaculate, it well be unchallengeable in the future. In fact, there are critics of Einstein’s theory today: according to Joseph Lévy, “the speed of light was erroneously found to be constant” [From Galileo to Lorenz… and Beyond 2002, p. 2]. In the age of Galileo the Aristotelian science was replaced by the “New Physics” within some decades, but the institutional system of research was in embryotic form at that time. So the opinion of those who have some doubt about the flexibility of our textbook – academy – big science based system is understandable. After all, a theory’s acceptance is only its respect’s indicator, but not surely of its truth.
On the other hand, the simplicity of this mass means slower than light, zero mass means speed of light equation urges caution. The ancient Greeks believed, inter alia, in the harmony, beautifulness and mathematical nature of “natural laws.” I don’t believe that the adaptation of the mental organs of our hunter-gatherer ancestors to their environment prepared us to understand the physics (after all, we have to use higher mathematics and other tricks), so it is reasonable to introduce an anti-Ockham rule. According to it, nature is not necessarily organized by simple and transparent laws, and it is always suspicious if an explanation is too elegant, too regular etc. Circle is perfect – but the orbit of a planet isn’t a circle. The history of physics is the history of the appearance of more and more complicated theories.