Quantum computing

Originally posted by humy
I have researched the possible applications of quantum computers and come to the conclusion that the only one that counts i.e. the only one that has any real usefulness or value to humanity is certainly not the usual applications stated (finding large prime numbers and decryption being two of them ) but rather is with making them do certain types computer simul ...[text shortened]... s fold and understanding of chemical reactions esp organic chemical reactions in life chemistry.

The large prime factors problem is just a handy example of something quantum machines should be good at and takes a while on a conventional machine.

Don't underestimate the other applications. Quantum machines give a mechanism for safe key transmission - this is a big thing as the theoretically unbreakable one-time-pad has in fact been cracked on at least 63 occasions due to poor key discipline.

Originally posted by humy
It is that inference that I believe is false when it is applied to quantum computers ....

As I said, I think you are misunderstanding them. I don't think that they are arguing that because a lot has been invested in standard computer technology, therefore quantum computers are unlikely to replace them. Instead they are saying it would be astonishing ie people would find it amazing - regardless of how likely it was based on technological considerations.
Take the example of Wikipedia. In hindsight, and considering the technological considerations, it is unremarkable that it took over from published encyclopedias. It was however astonishing to those who witnessed the transition, and even more astonishing when taking into consideration the amount of effort that went into the published encyclopedias.

Education is in a similar astonishing transition, where students will no longer attend university by living on campus, but rather most education can be done remotely via the internet at a tiny fraction of the cost. We know it is possible. There are no real reasons why it won't happen. But it will be astonishing nonetheless.

Originally posted by twhitehead
As I said, I think you are misunderstanding them. I don't think that they are arguing that because a lot has been invested in standard computer technology, therefore quantum computers are unlikely to replace them. Instead they are saying it would be astonishing ie people would find it amazing - regardless of how likely it was based on technological consid ...[text shortened]... possible. There are no real reasons why it won't happen. But it will be astonishing nonetheless.

Instead they are saying it would be astonishing ie people would find it amazing - regardless of how likely it was based on technological considerations.

Oh I see! I now get your meaning. You are saying they meant it would be 'astonishing' in a purely psychology as opposed to a rational sense because of the irrational way of thinking of actual people as opposed to the rational way we should think. People could find it astonishing because they are thinking irrationally (while those that are thinking rationally obviously won't ) . Yes, I now see how they could have meant that. I hadn’t considered that possibility of them meaning that -probably because I don't think irrationally like that so don't automatically imagine the possibility that other people might!

The only weakness of having a rational mind is that this can make it harder to understand irrational minds.

Originally posted by humy
People could find it astonishing because they are thinking irrationally (while those that are thinking rationally obviously won't ) .

I am not entirely convinced that 'irrational' is the best way to put it.
Are you saying that you, being rational, were not astonished by the way cellphones have taken over the world? Am I irrational because I was astonished by it?
I don't think it is a case of being irrational, but rather a case of not being privy to all the information. I didn't see it coming.

A small question:

Do you use the same programming language, like Java or C#, when your target is a quantum computer?

Or do you need to think totally different and learn from the beginning to unleash the power of a quantum computer?

Originally posted by twhitehead
I am not entirely convinced that 'irrational' is the best way to put it.
Are you saying that you, being rational, were not astonished by the way cellphones have taken over the world? Am I irrational because I was astonished by it?
I don't think it is a case of being irrational, but rather a case of not being privy to all the information. I didn't see it coming.

Are you saying that you, being rational, were not astonished by the way cellphones have taken over the world?

I wasn't astonished by that particular thing. But I don't think that was because I was 'rational' in particular but rather simply because I had little idea what to expect thus am unsurprised if something happened that nobody, including myself, predicted.

Am I irrational because I was astonished by it?

well, I guess that would depend on [i[why[/i] you were astonished by it. For example, did you specifically predict that that, or anything very similar to that, would not happen and, if so, why?

I didn't see it coming.

But not seeing something coming shouldn't necessarily make you rationally astonished by it because you can often perfectly rationally expect many things and changes to often happen that were not predicted because we live in a world that is like that.

Originally posted by FabianFnas
A small question:

Do you use the same programming language, like Java or C#, when your target is a quantum computer?

Or do you need to think totally different and learn from the beginning to unleash the power of a quantum computer?

Do you use the same programming language, like Java or C#, when your target is a quantum computer?

I am not an expert in this but I believe the answer to that is simply no. That is because, as far as I am aware, it is not possible to make a quantum computer, at least not efficiently and effectively, run any program that requires a number of tasks to be done in sequence ( please will someone here correct me here if this is not necessarily the case ) i.e. requiring one operation not to be started before a previous operation was completed so that the output of that previous operation can be fed into the input of the next operation. I assume either all or all but the most ridiculous trivial and useless programs in java and C++ etc would require at least one sequential operation to be done.

Originally posted by humy

Do you use the same programming language, like Java or C#, when your target is a quantum computer?

I am not an expert in this but I believe the answer to that is simply no. That is because, as far as I am aware, it is not possible to make a quantum computer, at least not efficiently and effectively, run any program that requires a number o ...[text shortened]... useless programs in java and C++ etc would require at least one sequential operation to be done.

Thank you for your answer. It helps some but questions remain.

In Java I can create threads to do simultaneous computing, but still, only if they don't collide with eachother in some way. But the arguments for that thread I give a combination of bits that is *either* one or zero, not one and zero at the same time. So in order to make use of its quantum states I have to do something in particular to make it happen.

I suppose that the most of memory in a quantum computer is the classic one, and only a fraction in the inner core is of the quantum type, right? So perhaps actually you use Java with a quantum toolbox? And the qubits are accessed with this toolbox...?

Originally posted by FabianFnas
Thank you for your answer. It helps some but questions remain.

In Java I can create threads to do simultaneous computing, but still, only if they don't collide with eachother in some way. But the arguments for that thread I give a combination of bits that is *either* one or zero, not one and zero at the same time. So in order to make use of its quantum ...[text shortened]... actually you use Java with a quantum toolbox? And the qubits are accessed with this toolbox...?

I am afraid I am unsure of the answer to your questions because this is unfortunately well outside my area of expertise and I only know the very fragmented and limited knowledge I gained about it from the net with absolutely none of my knowledge of that coming from any of the university courses I did. Although I did cover some basic quantum physics at university, none of that told me anything specific about quantum computers or qubits in particular -the material was too basic and generic for that. In particlar, I have no idea how or even if quantum computers deal with memory!

However, I did do plenty of java at university and I know exactly what you are talking about by the technical term "threads" in this context. Unless I am mistaken, program threads would be a poor analogy to what is going on in a quantum computer because, although both threads and quantum computers allow parallel processing of information, a fundamental difference is that each program thread is sequential even though several threads can act collectively to do paralell processing. This contrasts with what goes on in a quantum computer each time it does a 'single' program run which is pure parallel processing i.e. no sequential processing period. Another problem with the analogy of compering threads with quantum computer is that program threads in, say, java, don't necessarily have to interact/communicate with each other to do something useful (although they often do ) while qubits in a quantum computer MUST necessarily interact/communicate with each other to do something useful because there isn't really much a single qubit can do all by itself!

Originally posted by humy
I am afraid I am unsure of the answer to your questions because this is unfortunately well outside my area of expertise and I only know the very fragmented and limited knowledge I gained about it from the net with absolutely none of my knowledge of that coming from any of the university courses I did. Although I did cover some basic quantum physics at universit ...[text shortened]... a quantum computer MUST necessarily interact/communicate with each other to do something useful.

But the quantum states are fun, aren't they?

Like I go to work AND to the golf course at the same time! As long as noone observes me...

Originally posted by humy
But not seeing something coming shouldn't necessarily make you rationally astonished by it because you can often perfectly rationally expect many things and changes to often happen that were not predicted because we live in a world that is like that.

Maybe you are just not easily impressed.

Originally posted by FabianFnas
Do you use the same programming language, like Java or C#, when your target is a quantum computer?

I would think that as humy says, a quantum computer cannot be used as a standard processor. I think that the quantum bits would be treated the same way we treat sensors or other attachments to a computer, rather than integral components of the instruction processor itself.
So you would still use standard programming language and all the quantum magic would take place in data rather than in code.
Having said that, the quantum bits themselves can be put in circuits such that they perform various logical functions in sequence, so they are not to be viewed quite the same as separate memory locations.
If you want to know more you could start here:
http://en.wikipedia.org/wiki/Quantum_circuit
I don't pretend to understand it.