Quantum computing

A common mistake that the kind of language they were using causes is the
belief some people have that when you use Newtonian gravity in some
situations and general relativity in others it's not because Newtonian gravity
is simply a computationally cheaper method of calculating gravitational forces
at a cost in accuracy, that is often not important.
No they get the idea that the laws of physics are actually different on different
scales, that sometimes objects follow newtons laws and sometimes Einstein's.

All the matter you see around you is made up of tiny particles following the
simple basic laws of quantum physics [or whatever deeper laws QM is an approximation
for] and ALL the other laws of physics and equations we use are higher level
approximations for describing the behaviour of large groups of these particles
in different circumstances. These higher level laws are obviously still important
to discover as you cannot practically describe [for example] the weather by
modelling the actions of every subatomic particle that makes up the atmosphere
and oceans using the Schrödinger equation. But what the weather is actually doing,
is having all the individual particles follow the laws of quantum mechanics.
The higher level approximations we use are emergent properties of the system and
not fundamental laws describing how it actually works.

Originally posted by googlefudge
A common mistake that the kind of language they were using causes is the
belief some people have that when you use Newtonian gravity in some
situations and general relativity in others it's not because Newtonian gravity
is simply a computationally cheaper method of calculating gravitational forces
at a cost in accuracy, that is often not importan ...[text shortened]... e emergent properties of the system and
not fundamental laws describing how it actually works.

But you do know how it works, right?

Originally posted by DeepThought
Essentially it is statistical. In quantum theory the modulus square of the wavefunction evaluated at some position gives the probability per unit volume of finding a particle in an arbitrarily small box centred on that position. Imagine the wave-function is a Gaussian function - a bell curve, then the width of the bell curve is the uncertainty in findi ...[text shortened]... ength" on Wikipedia talks about this, see especially the bit about "Limitations on Measurement".

this is full of in house terminology although the comparison between a particle and a cannonball is quite helpful. Many thanks.

Originally posted by googlefudge
A common mistake that the kind of language they were using causes is the
belief some people have that when you use Newtonian gravity in some
situations and general relativity in others it's not because Newtonian gravity
is simply a computationally cheaper method of calculating gravitational forces
at a cost in accuracy, that is often not importan ...[text shortened]... e emergent properties of the system and
not fundamental laws describing how it actually works.

Although your statement is broadly true, there is the caveat that there is no (widely accepted) quantum theory of gravity.

Originally posted by KazetNagorra
Although your statement is broadly true, there is the caveat that there is no (widely accepted) quantum theory of gravity.

Indeed, Hence this caveat "[or whatever deeper laws QM is an approximation
for]"...

Originally posted by robbie carrobie
But you do know how it works, right?

What the weather?

Broadly, it's an ongoing area of research.

Originally posted by googlefudge
What the weather?

Broadly, it's an ongoing area of research.

no the movement of particles, thats what quantum mechanics is about right?

Originally posted by robbie carrobie
no the movement of particles, thats what quantum mechanics is about right?

not just their movement but other properties such as electric charge, spin orientation (which is a misleading term because the word "spin" here shouldn't be taken too literally )
plus how they interact with each other
plus under what circumstances do they behave like a wave rather than like a particle and vice averse.
That is what quantum mechanics is about.
( anyone; did I leave anything out there? )

Originally posted by humy
not just their movement but other properties such as electric charge, spin orientation (which is a misleading term because the word "spin" here shouldn't be taken too literally )
plus how they interact with each other
plus under what circumstances do they behave like a wave rather than like a particle and vice averse.
That is what quantum mechanics is about.
( anyone; did I leave anything out there? )

It appears to me that no one really knows how they 'work' and all of these systems are simply expressions attempting to explain and predict their behavior, is it not the case? Kind of like observing a golf course, you can determine that some balls will traverse a certain trajectory, mathematically, but you cannot explain why golfers will hit the ball in a certain way, is it not the case?

Originally posted by robbie carrobie
It appears to me that no one really knows how they 'work' and all of these systems are simply expressions attempting to explain and predict their behavior, is it not the case? Kind of like observing a golf course, you can determine that some balls will traverse a certain trajectory, mathematically, but you cannot explain why golfers will hit the ball in a certain way, is it not the case?

It appears to me that no one really knows how they 'work' and all of these systems are simply expressions attempting to explain and predict their behavior, is it not the case?

But why cannot it be true that how 'they work' IS how they behave and nothing else?

Kind of like observing a golf course, you can determine that some balls will traverse a certain trajectory, mathematically, but you cannot explain why golfers will hit the ball in a certain way, is it not the case?

Your analogy indicates to me that you assume the existence of a deeper level of reality which we currently have no evidence for. Sticking to your analogy; what if the golfers are mindless so that there is no “why” golfers will hit the ball in a certain way? Or what if there are balls with trajectories despite there being no golfer existing to hit them?
What if the only thing we can say about the ball is its trajectory because there is nothing more than its trajectory (i.e. nothing 'behind' that ) and its trajectory behavior is just a brute fact?
If you ask "why A" and the answer is B and then you ask "what B" and the answer is C and so on, at some point, you are going to reach a "why N" where there is no 'why N' because N is just a brute fact and that is that. The general assumption (because of Occam's razor ) it that quantum behavior is probably like that N. After you explained some behavior by some law and then you explained that law by some higher law and so on, you are going to arrive at a top law of physics which just is i.e. is just a brute fact. After that, there is no why or how. Instead, all you have is an equation to describe it with nothing 'behind' it.

Originally posted by humy

It appears to me that no one really knows how they 'work' and all of these systems are simply expressions attempting to explain and predict their behavior, is it not the case?

But why cannot it be true that how 'they work' IS how they behave and nothing else?
[quote] Kind of like observing a golf course, you can determine that some ball ...[text shortened]... top law of physics which just is i.e. is just a brute fact. After that, there is no why or how.

Well the difference between the philosopher and the religionist is that the philosopher attempts simply to understand the problem and its constituent parts so as to form a whole whereas the religionist attempts to proffer a solution. Its seems to me to be similar to the scientist and the metaphysician. The former is content to understand how a system functions without feeling the necessity to ascertain why.

Originally posted by robbie carrobie
Well the difference between the philosopher and the religionist is that the philosopher attempts simply to understand the problem and its constituent parts so as to form a whole whereas the religionist attempts to proffer a solution.

Actually, no, the religionist attempts to hide the problem. The religionist gives himself 'answers' that aren't really answers but just sound like answers. Things like 'God did it' which really don't tell you anything.

Originally posted by twhitehead
Actually, no, the religionist attempts to hide the problem. The religionist gives himself 'answers' that aren't really answers but just sound like answers. Things like 'God did it' which really don't tell you anything.

not really, the philosopher will look at the morality or otherwise of a problem and shall be content to have accurately described and understood its constituent parts, the religionists will also look at the problem and devise a course of action with respect to the morality of the issue, for example, you must treat others as you yourself expect to be treated. Now this is fine if you are a rational being and not a serial killer. I suspect that at one point science and metaphysics were one and the same and separated at some point in time into two distinct branches. Science is fine for describing how a system functions but we should recognize its limitations in describing why and leave that to metaphysics. The trend now is to attempt to utilize science to offer an understanding of morality and is in my opinion pure folly.

Originally posted by robbie carrobie
Well the difference between the philosopher and the religionist is that the philosopher attempts simply to understand the problem and its constituent parts so as to form a whole whereas the religionist attempts to proffer a solution. Its seems to me to be similar to the scientist and the metaphysician. The former is content to understand how a system functions without feeling the necessity to ascertain why.

attempts simply to understand the problem and its constituent parts so as to form a whole

What kind of “problem” are you referring to here? The “problem” of understanding of what is going on in the physical world? Or the “problem” of how to create technology to solve some human need? If neither of these two, exactly what KIND of "problem" are you referring to here?

….whereas the religionist attempts to proffer a solution

“proffer a solution” to exactly what problem? If the “problem” of understanding of what is going on in the physical world, scientists clearly have been and are already doing that while religion has totally failed miserably. If the “problem” of how to create technology to solve some human need, again, scientists clearly have been and are already doing that while religion has totally failed miserably. If neither of these two kinds of “problems”, then, I ask you again, what kind of “problem” are you referring to here?

The former is content to understand how a system functions without feeling the necessity to ascertain why.

-because, as yet, there is not evidence that a “why” (of the kind you assume to exist ) exists so no rational reason to assume there necessarily must be a “why” to know. What is your PREMISE for your (apparent ) belief that there must be a 'why' to everything? (if that is not your belief, then why cannot the top laws of quantum physics be a brute fact? ) Why cannot there exist brute facts?

http://en.wikipedia.org/wiki/Brute_fact

reminder of what I said in my previous post:

“If you ask "why A" and the answer is B and then you ask "what B" and the answer is C and so on, at some point, you are going to reach a "why N" where there is no 'why N' because N is just a brute fact and that is that. The general assumption (because of Occam's razor ) is that quantum behaviour is probably like that N. After you explained some behaviour by some law and then you explained that law by some higher law and so on, you are going to arrive at a top law of physics which just is i.e. is just a brute fact. After that, there is no how or why. Instead, all you have is an equation to describe it with nothing 'behind' it. “ ( my bad spelling corrected )

-Do you understand this?

Originally posted by humy

attempts simply to understand the problem and its constituent parts so as to form a whole

What kind of “problem” are you referring to here? The “problem” of understanding of what is going on in the physical world? Or the “problem” of how to create technology to solve some human need? If neither of these two, exactly what KIND of "problem" ...[text shortened]... escribe it with nothing 'behind' it. “ ( my bad spelling corrected )

-Do you understand this?

I have deliberately offered a generic description and will leave it at that, it was not my intent to introduce any specific issues as this is not the place for it. The problem may be one of morality, criminality, anything infact.

To say that there should be no rational reason as to why a system functions is to ignore or refuse to acknowledge reason. Ok you may describe how the universe functions in mathematical terms but cannot say why it was brought into existence. There is no assumption, its simply a question. To my knowledge I have not denied, nor given the impression that i have denied any facts. What I have done is merely to point out that science is ill fitted for describing morality or questions which go beyond what is merely physical.

Yes i think I understand what you are saying, essentially its an attempt to reduce everything to a convenient material level, which is fine if you are a scientist, but not a philosopher.