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March 21, 2019

Strong Emergence & Top Down Causation

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July 07, 2016

Constructive Empiricism - An introduction to Scientific Antirealism

(Abstracted from the Stanford University Online Library)

Copyright © 2014 by The Metaphysics Research Lab, Stanford University.

Constructive Empiricism:

Constructive empiricism is the version of scientific anti-realism promulgated by Bas van Fraassen in his famous book The Scientific Image (1980).

Van Fraassen defines the view as follows:

Science aims to give us theories which are empirically adequate; and acceptance of a theory involves as belief only that it is empirically adequate. (1980, 12)

A theory is empirically adequate exactly if what it says about the observable things and events in the world is true — exactly if it ‘saves the phenomena.’ (van Fraassen 1980, 12)

To understand the above account, one needs first to appreciate the difference between the syntactic view of scientific theories and van Fraassen's preferred semantic view of scientific theories.

On the syntactic view, a theory is given by an enumeration of theorems, expressed in some one particular language.

In contrast, on the semantic view, a theory is given by the specification of a class of structures (describable in various languages) that are the theory's models (the determinate structures of which the theory holds true).

As van Fraassen says,

To present a theory is to specify a family of structures, its models; and secondly, to specify certain parts of those models (the empirical substructures) as candidates for the direct representation of observable phenomena. (1980, 64)

A theory is empirically adequate, then, if appearances — “the structures which can be described in experimental and measurement reports” (1980, 64) — are isomorphic to the empirical substructures of some model of the theory.

Roughly speaking, the theory is empirically adequate if the observable phenomena can “find a home” within the structures described by the theory — that is to say, the observable phenomena can be “embedded” in the theory.

The constructive empiricist rejects arguments that suggest that one is rationally obligated to believe in the truth of a theory, given that one believes in the empirical adequacy of the theory.

For this epistemological argument to work, the distinction between empirical adequacy and truth has to be well-founded.

Summary:

Constructive empiricism is a view which stands in contrast to the type of scientific realism that claims the following:

Science aims to give us, in its theories, a literally true story of what the world is like; and acceptance of a scientific theory involves the belief that it is true. (van Fraassen 1980, 8)

In contrast, the constructive empiricist holds that science aims at truth about observable aspects of the world, but that science does not aim at truth about unobservable aspects.

Acceptance of a theory, according to constructive empiricism, correspondingly differs from acceptance of a theory on the scientific realist view: the constructive empiricist holds that as far as belief is concerned, acceptance of a scientific theory involves only the belief that the theory is empirically adequate.


Dr. Michela Massimi is a Ph.D from the London School of Economics, and a senior lecturer of philosophy at the University of Edinburgh.

In the following video, she explains Constructive Empiricism very nicely:


Terms used by Dr. Massimi:

1. "Scientific realism":
Is a positive epistemic attitude towards the content of our best theories and models, recommending belief in both observable and unobservable aspects of the world described by the sciences.

2. "Scientific Anti-realism":
In philosophy of science, anti-realism applies chiefly to claims about the non-reality of "unobservable" entities such as electrons or genes, which are not detectable with human senses.

3. "Epistemology":
Relating to knowledge or to the degree of its validation.

4. "Ontology":
The philosophical study of the nature of being, becoming, existence, or reality, as well as the basic categories of being and their relations.

5. "Empirical Adequacy":
Roughly speaking, if a theory works in practical life, it is called empirically adequate.

6. "Semantic aspect":
Semantics is the study of meaning.

7. "Syntactic aspect":
Syntax, or the study of structure.

December 13, 2015

A commercial Quantum Computer




Introduction:

A quick look at commercial quantum computers. These computers have human like intelligence, and are a totally different ball game from the Bill Gates type of computer.

Currently manufactured by a Canadian startup named D-Wave but others will follow soon.

D-Wave's quantum computer can hold in its "digital mind", possibilities that exceed the number of particles in the whole observable universe!

So if you gave such a computer a chess situation, or any real world issue, it would be able to ponder a number of relevant possibilities that exceeds the total number of particles in the whole observable universe!

Applications would be traffic control, air traffic control, weather predictions....political strategy...business strategy. War strategy. Very long list.

D-Wave's current machine can ponder 21000 possibilities simultaneously.

That's 2 multiplied by itself 1000 times. Larger than the number of particles in the observable universe.



© D-Wave Systems:

Jun 22, 2015

D-Wave Systems Breaks the 1000 Qubit Quantum Computing Barrier

New Milestone Will Enable System to Address Larger and More Complex Problems

Palo Alto, CA - June 22, 2015 - D-Wave Systems Inc., the world's first quantum computing company, today announced that it has broken the 1000 qubit barrier, developing a processor about double the size of D-Wave’s previous generation and far exceeding the number of qubits ever developed by D-Wave or any other quantum effort.

At 1000 qubits, the new processor considers 21000 possibilities simultaneously, a search space which dwarfs the 2512 possibilities available to the 512-qubit D-Wave Two.

In fact, the new search space contains far more possibilities than there are ‪particles in the observable universe.

Formidable power expanding very rapidly....the quantum computer reduces your Bill Gates type of computer to the status of a bullock cart, in certain applications.

Let us take a quick look at what makes a Quantum Computer tick. As explained by the founder of D-Wave.




Highlights:

1. Everytime you add these Qubits, you double the number of .....so the way I think this is, the shadows of these parallel worlds, overlap with ours, and if we are smart enough, we can dive into these parallel worlds, grab their resources and pull them back into ours.


So what is he talking about, when he talks of parallel worlds?

He is referring to the MWI, or the many worlds interpretation of Quantum Physics:

Many-worlds interpretation of Quantum Physics:

This interpretation implies that all possible alternate histories and futures [of anything] are real, each representing an actual "world" (or "universe").

The hypothesis states there is a very large—perhaps infinite number of universes, and everything that could possibly have happened in our past, but did not, has occurred in the past of some other universe or universes.

MWI is one of many multiverse hypotheses in physics and philosophy. It is currently considered a mainstream interpretation along with others.

Before many-worlds, reality had always been viewed as a single unfolding history. Many-worlds, however, views reality as a many-branched tree, wherein every possible quantum outcome is realised. Many-worlds reconciles the observation of non-deterministic events, such as random radioactive decay, with the fully deterministic equations of quantum physics.

THE BASICS OF QUANTUM COMPUTING:

Bloch Sphere representation of a QubitThe basic digit of a quantum computer is a QUBIT. It is a VECTOR, while the basic digit used in a conventional Bill Gates type of computer is a SCALAR.

Via Wikipedia:

Consider first a classical computer that operates on a three-bit register. The state of the computer at any time is a probability distribution over the 23=8 different three-bit strings 000, 001, 010, 011, 100, 101, 110, 111. If it is a deterministic computer, then it is in exactly one of these states with probability 1.

However, if it is a probabilistic computer, then there is a possibility of it being in any one of a number of different states. We can describe this probabilistic state by eight non-negative numbers A,B,C,D,E,F,G,H (where A = is the probability that the computer is in state 000, B = is the probability that the computer is in state 001, etc.). There is a restriction that these probabilities sum to 1.

The state of a three-qubit quantum computer is similarly described by an eight-dimensional vector (a,b,c,d,e,f,g,h), called a ket. Here, however, the coefficients can have complex values, and it is the sum of the squares of the coefficients' magnitudes, |a|2+|b|2+....+|h|2, that must equal 1. These squared magnitudes represent the probability of each of the given states. However, because a complex number encodes not just a magnitude but also a direction in the complex plane, the phase difference between any two coefficients (states) represents a meaningful parameter. This is a fundamental difference between quantum computing and probabilistic classical computing.

D-Wave has a 1000 qubit commercially successful quantum computer.