|
Jeremy,
I'm not sure that that last explanation is TRUE or FALSE. I do not know enough about quantum computing to make an educated guess. I will let your explanation stand and go about my day in blisfull ignorance.
Dave.
|
|
|
|
|
Are four qubits a quibble? 
|
|
|
|
|
It's more complicated than 3 states. The closest analogy would be a probability that the result is true or false. For that you need 2 numbers P(true) and P(false) with the constraint that P(true)+P(false)=1 and both are between 0 and 1. To read the result of a calculation, you run the program a large number of times and record the results and then use the average to figure out what P(true) and P(false) are.
But these are qubits, and so instead of P(true) and P(false) being normal numbers, they are complex numbers. This means that you can have P(true) = i. However when you measure the result, you will only get the absolute value of the result, so for that case P(true) = i is equivlelent to it being 1.
However, quantum calculations are not measurements, so if you have a bunch of qubits together, you can run quantum algorithms where the imaginary parts matter. Because of that you can run a bunch of calculations at the same time on the set of qubits, just like a particle can be at many places at the same time. For example, you can calculate multiple factors of a number all at the same time. As measurement is limited to probabilities though, you have to do it a number of times and average to find out what the result was.
|
|
|
|
|
Andy Brummer wrote: It's more complicated than 3 states.
In hindsight my three state comment was a bad explanation of it, but the bottom analogy should clear things up.
Andy Brummer wrote: For that you need 2 numbers P(true) and P(false) with the constraint that P(true)+P(false)=1 and both are between 0 and 1. To read the result of a calculation, you run the program a large number of times and record the results and then use the average to figure out what P(true) and P(false) are.
This isn't explaining it though. This is a text book definition. We can Google this. Give us a real explanation.
Andy Brummer wrote: To read the result of a calculation, you run the program a large number of times and record the results and then use the average to figure out what P(true) and P(false) are.
To me this has nothing to do with quantum theory. This is probability and averages. I don't see how a definite state dependent on the observer and probability are correlated on this level, because well they aren't.
Andy Brummer wrote: However, quantum calculations are not measurements
Don't use the term "measurement" so literally. That's thinking like an old machine. Quantum machines understand figurative - literally. 
Sorry man, but so far your post is trying to sound smart, but only making the problem worse. Do better. What I want to know is how one qubit of data is *literally* stored in physical memory, that's my next step.
Jeremy Falcon
|
|
|
|
|
The problem with explanations of quantum mechanics is that there are no analogies. The only way we have to work with it are mathematical equations. Unlike classical equations, the quantum mechanical equations don't make sense in any meaningful way to human beings. That makes it very difficult to explain.
So step one, you tore into the simple part of my explanation where I left out quantum mechanics describing why true, false plus something else is not a good way to explain it. It's much closer to weighted probability between the two values than a 3 value model. It's also relevant in that quantum mechanics is a purely probabilistic theory, it only predicts the probability of outcomes.
"measurement" has a very specific meaning in quantum mechanics, and is one of the most contentious parts of quantum mechanics. Quantum particles can move with or without measurement and the measurement changes the outcome, so it very important.
Each quantum computer has a different way of storing qubits, but the most simple example is the spin of an electron aligned with a magnetic field.
|
|
|
|
|
Andy Brummer wrote: The problem with explanations of quantum mechanics is that there are no analogies.
I gave you one with no math involved. Read it again. I swear to you, it's valid.
Andy Brummer wrote: The only way we have to work with it are mathematical equations. Unlike classical equations, the quantum mechanical equations don't make sense in any meaningful way to human beings. That makes it very difficult to explain.
Not true man. I just made it very easy to get. I get it. I explained it with my analogy. I'm asking you really read my joke analogy. I understand what you're getting at, is that it defies an old way of thinking. Numbers and math express our world on an intricate level. And equations fall short, etc. But they don't. The only fall short if you don't get the concept of observation being the very reason those equations come into play.
Andy Brummer wrote: So step one, you tore into the simple part of my explanation where I left out quantum mechanics describing why true, false plus something else is not a good way to explain it. It's much closer to weighted probability between the two values than a 3 value model. It's also relevant in that quantum mechanics is a purely probabilistic theory, it only predicts the probability of outcomes.
Then it's not truly quantum. Granted, my understanding of it is more theory than practical, but I get it. If anything, this would be an approximation of what someone thinks it is, but it's not quantum. Probability has nothing to do with it. They're still latching on to the old way of thinking. Seriously man, once you get it, you get it.
Andy Brummer wrote: Each quantum computer has a different way of storing qubits, but the most simple example is the spin of an electron aligned with a magnetic field.
I'm more of a software guy so I was thinking about the conceptual part, but hey this is good to know.
Jeremy Falcon
|
|
|
|
|
The joke argument is a different kind of indeterminacy, it is about a difference of interpretation. In quantum mechanics everyone agrees on the outcome. In quantum mechanics when you look away, things go multiple directions at once and then when you look at it, everything snaps back like it went in only one direction.
If you set everything up exactly the same way and then try it again, it will snap back but in a different direction. Eventually you can figure out what all the directions are by measuring it enough times. That's where the probability comes into play.
The way I think of it is that you drop a rock in a pond and instead of the rock making a splash it disappears and becomes the ripples on the pond. When you look for it again, it pops out somewhere. The bigger the wave, the more likely the rock is to appear at that location.
|
|
|
|
|
Andy Brummer wrote: The joke argument is a different kind of indeterminacy, it is about a difference of interpretation. In quantum mechanics everyone agrees on the outcome. In quantum mechanics when you look away, things go multiple directions at once and then when you look at it, everything snaps back like it went in only one direction.
Yes it's about interpretation, but it's an analogy. That's the point of an analogy, to look at something different to help the concept. That being said, it's not that different. The problem scientists are having is they think it's random because most logical scientists are thinking "scientifically". Their brains are too hard wired and understand reality in only one way. They'll probably have to die and new ones come in before we make major advances.
Andy Brummer wrote: If you set everything up exactly the same way and then try it again, it will snap back but in a different direction. Eventually you can figure out what all the directions are by measuring it enough times. That's where the probability comes into play.
What I'm saying though it that it's not random. It just appears that way since they don't yet see the big picture. Probability is just an approximation of an old way of thinking.
Andy Brummer wrote: The way I think of it is that you drop a rock in a pond and instead of the rock making a splash it disappears and becomes the ripples on the pond. When you look for it again, it pops out somewhere. The bigger the wave, the more likely the rock is to appear at that location.
We can't assume more likely to do anything anywhere yet. Most folks barely understand it enough to make that claim. Probability is clouding the situation.
Jeremy Falcon
|
|
|
|
|
Can you give me an example of how the probability interpretation is wrong? If it is just an approximation of an old way of thinking, than can you tell me more about the new way?
|
|
|
|
|
Andy Brummer wrote: If it is just an approximation of an old way of thinking, than can you tell me more about the new way?
I'm at work right now, but since you're genuinely asking I'll write a real reply... like a real real one. But it'll take a few days to do it justice since I gotta get the crap out of my head into something that resembles something more coherent than clutter.
Jeremy Falcon
|
|
|
|
|
cool, I'm looking forward to it.
|
|
|
|
|
Hey man, so every time I sit down to think about really typing something out about this, none of it *directly* related to the actual bite storage of mechanism the current quantum computers are attempting to emulate quantum theory with. My understanding of it is more of the metaphysical, which sounds cliché to say, but that's true in the respect how this whole quantum process creates the foundation of what we call reality and the "meta" part is about the parts we don't understand yet coming into play.
Anyway, that's all vague sounding hoopla, so I'll say it like this. My understanding of came from the fact I've acting on the side in the past few years. And playing different personalities has taught me that one thing can be several. Not just mentally either, but that's the only part we understand because our entire existence and concept of reality revolves around our perception of it that the body gives us. So even though mental and physical worlds work similar, we think they're not. For instance, the atoms that made and apple came into form to make that apple because we "asked" the atoms to make an apple so to speak. Out of all the things we could've asked atoms to make, apple was the way to go. Of course, we're not aware of any of this because it's an underlying process that happens "magically" and we call this reality. Einstein got this. He knew reality is a joke, an illusion, that can be mended. It just works much, much slower than that of the mind. The mind is the speed of thought.
What I'm trying to say is we created the apple. The apple did not create itself. To a different species there's no guarantee that apple is an apple as you and have both come to understand an apple. For that matter, we have no guarantee you and I see the same apple. We simply know that we see something and we agreed on calling it the same thing.
I hope this is making sense. If I get in an article writing mood I'll explain this better. But, the point I'm getting at is that has nothing to do with probability. That's just a "first stab" at it and using the word "quantum" in computers as marketing. The real theory suggest we can have something be two things at once. Not it might appear here and there over a coin flip, it's actually both, even in the psychical world.
Jeremy Falcon
|
|
|
|
|
Thanks for responding. What you are talking about is something much deeper and complicated than quantum mechanics.
Quantum mechanics are a set of mathematical rules to compute how subatomic particles interact. It can be used to compute the atomic spectra of atoms to an extremely precise level, it predicts the energy distribution of black body radiation, and the interference pattern seen in the two slit experiment, along with properties like superconductivity and superfulidity. It can also tell you why glass is clear, metals are reflectors and conductors, and what effects doping silicon will have and why.
While some of the interpretations of quantum mechanics deal with superposition and particles being multiple places at the same time, the most important part of the theory is it's ability to accurately predict the results of experiments. The rules of quantum mechanics and it's mathematically accurate predictive results allow you to calculate things like prime number factorization extremely fast. It just happens that some of those calculations involve superposition.
|
|
|
|
|
Thanks for the explanation there. And you're right what I'm getting at is much deeper, but I just know the two are related. I'm on my phone right now and still don't type too fast on it, but the best way I know to say it is like what you're explaining is an after the fact. You're right, but it's still a result of human thinking the old way. We're spot trying to "measure" something we don't really understand. Like most medicine doesn't heal the body, if just stops symptoms while the body heals itself. Science is only just starting to understand the body. The mechanical side of this quantum is barely starting to understand the "why" of this stuff. It's just quantifying data as it were.
It's like this. As you said, we're talking about the same thing, but on a different level. Like making a cake. I'm talking about invredients such as eggs and flour. You're talking about know how to predict how it will taste when it's out of the oven and iced. There's a set of rules that say "if the icing does X we can always assume it's frothy and taste like Y." I'm saying once we can really understand the makings of a cake we can take the same ingredients and make a bagel.
Jeremy Falcon
|
|
|
|
|
Einstein said if you know what you're talking about you can explain it to an 8 year old. So explain it.
Jeremy Falcon
|
|
|
|
|
Einstein never accepted Quantum mechanics as a valid theory, so I don't think his opinion is all that relevant. 
|
|
|
|
|
Ha ha. Touché.
Jeremy Falcon
|
|
|
|
|
No offence, but IMO all analogies are pretty sh*t.
A joke that is funny or not depending on who's listening? It doesn't really work that way.
A possibly loaded coin that has been flipped but not observed yet? It doesn't even work that way - that's just fuzzy logic, and that doesn't capture much of the "funny quantum business", only the "weird indecision thing". If you visualize the coin as a point on a line, a cubit is a point on a sphere.
That sphere is close, but it dies if you involve more than 1 cubit, so what's the point? Just learn the math and stop desperately trying to find classical analogies. It's not classical, that's the whole point.
|
|
|
|
|
harold aptroot wrote: No offence, but IMO all analogies are pretty sh*t.
No offense taken.
harold aptroot wrote: A joke that is funny or not depending on who's listening? It doesn't really work that way.
You're thinking the old way. Trust me man, it's time to learn again. Get out of your head and well get back into your head, but in a different way.
Jeremy Falcon
|
|
|
|
|
It's all superposition* until I observe one actually working.
Or, you can think of it as a magical machine that tell you what you want to hear, as the result is dependent upon the observer (as you yourself stated.) I imagine the government and Fox News are therefore very interested in such devices.
As to the quantum computing being the future of computing, hogwash. While it may be that something will eventually exist that can perform computation in a quantum space, it will be for only a select set of problems in which the probability calculations are essentially handled by the quantum space itself rather than the "soft" space of binary bits. And ironically, because the qubit (or qubytes, or whatever) represent a probability, you have to run the algorithm numerous times to get the answer out of the distribution curve. It will be interesting to see the performance benefit of that.
But why do I say hogwash? Because, except for certain very specific algorithms which require massive computation, this is not something your Facebook user is going to need. And besides, we are barely wrapping our head around distributed multi-threaded applications, what would probability programming language look like? Let's be real - the world we live in is state-full and the programs we write need to interact with a state-full world, not an indeterminate probabilistic one.
Anyways, your question is great and the responses are quite interesting too.  Hope you don't mind the nay-sayer attitude. It's just that I get tired of reading about all these theories that promise to revolutionize life as we know it.
* - pun on supposition, or, if you prefer, superstition.
|
|
|
|
|
Marc Clifton wrote: As to the quantum computing being the future of computing, hogwash. While it may be that something will eventually exist that can perform computation in a quantum space, it will be for only a select set of problems in which the probability calculations are essentially handled by the quantum space itself rather than the "soft" space of binary bits. And ironically, because the qubit (or qubytes, or whatever) represent a probability, you have to run the algorithm numerous times to get the answer out of the distribution curve. It will be interesting to see the performance benefit of that.
That's the catch though. It has nothing to do with probability. Our current iteration of it is like a first draft. We're trying to apply old-school laws to a something 99% of the world just does not understand. It's like asking a blind kid to tell us what the color blue is. Good luck. Most people just don't see it, but such is the nature of life. The masses are slow to catch up (if ever).
Marc Clifton wrote: But why do I say hogwash? Because, except for certain very specific algorithms which require massive computation, this is not something your Facebook user is going to need. And besides, we are barely wrapping our head around distributed multi-threaded applications, what would probability programming language look like? Let's be real - the world we live in is state-full and the programs we write need to interact with a state-full world, not an indeterminate probabilistic one.
We're at the very start of it. Think of it like the Wintel relationship, Windows gets more bloated so machines get faster to pretty much give us the same speed. The problems of tomorrow will be much greater and different than the problems of today. So there will be a need, we just haven't invented all of those needs yet.
Marc Clifton wrote: Anyways, your question is great and the responses are quite interesting too. Hope you don't mind the nay-sayer attitude. It's just that I get tired of reading about all these theories that promise to revolutionize life as we know it.
Nah it's cool. I'm rough around the edges, sure. But I like it when people say what they're thinking.
Didn't say I was gonna upvote you though.
Jeremy Falcon
|
|
|
|
|
Jeremy Falcon wrote: It has nothing to do with probability.
But I thought it did. From what I've read, with a qubyte, for example, it is in all 256 possible states simultaneously until it is collapsed into a single specific observable state. Quantum computation can therefore me more efficient because you can work within the realm of "all possible answers" and only the most probable ones will resolve after repeated runs. At least that's my lay understanding.
Jeremy Falcon wrote: We're trying to apply old-school laws to a something 99% of the world just does not understand.
Indeed. To some extent, it seems like a solution waiting for problems. And god only knows, we humans are good at creating problems (as you said.)
Marc
|
|
|
|
|
Marc Clifton wrote: But I thought it did. From what I've read, with a qubyte, for example, it is in all 256 possible states simultaneously until it is collapsed into a single specific observable state. Quantum computation can therefore me more efficient because you can work within the realm of "all possible answers" and only the most probable ones will resolve after repeated runs. At least that's my lay understanding.
It turns out I need to clarify. My understand of the quantum world and the current implementation of it with quantum computers are two different things. You are correct in the implementation of it currently, but it's an approximation of what the quantum concept is all about. It's asking for real cheese, but giving us Velveeta to try and fool us.
Marc Clifton wrote: And god only knows, we humans are good at creating problems (as you said.)
Amen to that brother. The mass seems to love that nonsense, but it's where we're headed ready or not.
Jeremy Falcon
|
|
|
|
|
Jeremy Falcon wrote: My understand of the quantum world and the current implementation of it with quantum computers are two different things.
How so? My own understanding of the quantum world is based almost exclusively on what I've read from the lectures Feynman gave on quantum mechanics (the rest that I read from lay "reporting" is theoretical drivel, in my opinion), so I'm quite interested in how you view the two as different and why it's an approximation. Certainly, I can't answer that question myself even though I agree with you!
Marc
|
|
|
|
|
Marc Clifton wrote: Certainly, I can't answer that question myself even though I agree with you!
Well, I come to it from a different angle. Keep in mind I'm a tech-geek by nature, but for the past few years I've been studying human nature and acting rather than pure tech stuff. So, I picked up some human nature things I can apply to it. It's something I'm just gonna have to really write about to make sense of. But basically I'm saying the whole randomness, probability based iteration is looking at the quantum world through blinders. Our concept of motion even doesn't exist in a higher dimension. Motion (and thus time) itself is a limitation, much like this randomness.
I gotta collect my thoughts on all of this and just read up on some of the tech side of it again and just write an article on my take of it. But the best way I can explain it right now, as with Andy's examples in this thread, about particles appearing in different locations is they are not. We see them that way because we're limited, not the particles.
Jeremy Falcon
|
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
