Quantum computing

No faster than conventional systems?

http://www.bbc.co.uk/news/science-environment-27264552

Originally posted by robbie carrobie
No faster than conventional systems?

http://www.bbc.co.uk/news/science-environment-27264552

This quantum computer may well not be no faster than conventional computers because it probably is still too early in the science to talk about truly useful quantum computers.

However, it may not be many more years before truly useful quantum computers come of age.
It certainly is inevitable that truly useful quantum computers will eventually become of age and will do some types, NOT all types, of information processing zillions of times faster than possible by any conventional computer. It is just a question of when, not if. We can be sure of this because there is nothing in the laws of physics that says this is impossible and the science indicates that, although there are some extremely difficult technical barriers still to cross, not one of them is actually physically insurmountable. And you consider it as being a bit like a 'law of science' that, if a technical barrier is not actually physically insurmountable then, no matter how hard that barrier is to cross, science will inevitably and eventually one day find a way to cross it. It is just a question of how long before it does so; one year? ten years? a million years? (but it will not take anything like a million years in this case! probably less than 100 years I would think )

Originally posted by humy
This quantum computer may well not be no faster than conventional computers because it probably is still too early in the science to talk about truly useful quantum computers.

However, it may not be many more years before truly useful quantum computers come of age.
It certainly is inevitable that truly useful quantum computers will eventually become of ag ...[text shortened]... anything like a million years in this case! probably less than 100 years I would think )

Its all a bit iffy tis it not. Now i studied computing science way back in the day when cobol and pascal were still relevant languages at least for teaching purposes and the Pentium P2 was state of the art and i have been relatively interested ever since. What type of information processing are you referring to? and why will a quantum computer be able to do it a zillions of times faster? ( I can understand the concept of binary and how it works conventionally and can see why having the property of being either a 1 or a 0 or both simultaneously as opposed to simply being a 1 or a 0 definitely would speed things up, it appears to me simply like a switch that you don't need to turn on or off, its simply on or off depending on whether you need it to be on or off)

Originally posted by robbie carrobie
No faster than conventional systems?

http://www.bbc.co.uk/news/science-environment-27264552

Show me the apps and I'll show you the market-driven motivation to make quantum computing a reality.

Originally posted by robbie carrobie
No faster than conventional systems?

http://www.bbc.co.uk/news/science-environment-27264552

Jury's still out.

Originally posted by robbie carrobie
Its all a bit iffy tis it not. Now i studied computing science way back in the day when cobol and pascal were still relevant languages at least for teaching purposes and the Pentium P2 was state of the art and i have been relatively interested ever since. What type of information processing are you referring to? and why will a quantum computer be ab ...[text shortened]... t need to turn on or off, its simply on or off depending on whether you need it to be on or off)

Its all a bit iffy tis it not.

If you mean whether truly useful quantum computers will eventually be made, no. I have studied this subject in depth and I can tell you it definitely will happen, the only iffy part is when.

What type of information processing are you referring to?

Although there is a huge amount of hype of quantum computers doing such things such as decrypting encryption codes a zillion times faster or finding massively high prime numbers a zillion times faster, and although there is no doubt that they will be able to do those things, the only really significantly beneficial information processing for humanity that quantum computers will be able to do will be computer simulation of quantum systems and, probably to much lesser extent, computer simulations of none quantum systems.

The reason why faster computer simulations of quantum systems would be so beneficial is because, currently, the most powerful computers take so long to computer simulate those quantum systems ( such as superconductors and the complex folding process of protein molecules in living cells ) that this has acted as a showstopper to any rapid progress in understanding these complex systems.
Truly useful quantum computers will remove that showstopper and allow rapid gains in the understanding of these processes because it would be a powerful research tool, a bit like how the first truly useful microscope removed the main showstopper for research into the microscopic world and thus massively speed-up the research into the microscopic.
In the case of quantum computers, it would massively speed up research into such things as superconductors, semiconductors ( including those in LEDs and solar cells thus speed up reserch into solar power and more energy efficient LEDs ) , and chemical reactions in organic chemistry ( and that would speed up medical research ) and several other important areas of quantum research.

and why will a quantum computer be able to do it a zillions of times faster? ( I can understand the concept of binary and how it works conventionally and can see why having the property of being either a 1 or a 0 or both simultaneously as opposed to simply being a 1 or a 0 definitely would speed things up, it appears to me simply like a switch that you don't need to turn on or off, its simply on or off depending on whether you need it to be on or off)

if, with each one particle state, you can represent any value between 0 and 1 rather than just either 0 or 1, and if you can process information WHILE many such particles have possible values between 0 and 1, the amount of possible values you can have for each bit WHILE they are processing those values are zillions (infinite in theory but I assume would be a very large finite number in practice ) and that massively increases the amount of information you can squeeze out of just a few particle.

Suitable particles for doing this are called “quantum bits” or “qubits” for short. And, just like the book I am currently writing about it (and the following IS an actual direct quote from my currently unfinished book )

"... Unlike with classical binary bits in classical computers, each extra qubit you add to a quantum computer doubles the amount of possible information processing that the computer can do. If the computer used and entangled just 2 qubits, it wouldn't be able to do much! But if it entangled 3 qubits, it would be able to do 2 times the information processing of what it could do with just 2 bits, and if it entangled 4 qubits, it would be able to do 4 times the information processing of what it could do with just 2 bits and if it entangled 5 qubits, it would be able to do 8 times the information processing of what it could do with just 2 bits and so on.

But, hypothetically, and this is where it finally gets really interesting, if the quantum computer could be made to entangled just 300 of these qubits, it would be able to do more calculations per second than there are particles in the known universe!..."

That makes it zillions of times faster than any classical computer no matter how large you make it! It would allow the quantum computer to do in seconds what a classical supercomputer would take a billion years to do! Obviously, only having to wait a few seconds rather than a billion years for the result of an important computer simulation will massively speed up research.

Originally posted by humy

Its all a bit iffy tis it not.

If you mean whether truly useful quantum computers will eventually be made, no. I have studied this subject in depth and I can tell you it definitely will happen, the only iffy part is when.

What type of information processing are you referring to?

Although there is a huge a ...[text shortened]... llion years for the result of an important computer simulation will massively speed up research.

Its really quite interesting and i thought you were an alchemist trying to change lead into gold ( a little pun on scientific quackery)

just think you might be able to solve chess!

Originally posted by robbie carrobie
No faster than conventional systems?

http://www.bbc.co.uk/news/science-environment-27264552

The bottom line of it all is the ability of quantum mechanics to do this superposition thing where a particle, say a carbon atom or a photon, can appear to be in two or more places at the same time or can be at several energy levels at the same time. So you can have a gate that is a not, a nor, and, nand all at the same time which of course takes separate circuits in classical computers.

So if you have enough of these kind of quantum processors, like maybe hundreds or even thousands, then things get interesting and they can do things in parallel that even the best of classical parallel computers cannot do, but the things that a classical computer does like calculating matrixes and such it might not be any faster but going through a list it can do that a million times faster.

My guess is 20 or more years from now when quantum comes on line, there will be a hybrid classical/quantum computer where each one will have its strengths and will be used to squeeze the maximum amount of computing that could be done with both systems working together.

Originally posted by sonhouse
The bottom line of it all is the ability of quantum mechanics to do this superposition thing where a particle, say a carbon atom or a photon, can appear to be in two or more places at the same time or can be at several energy levels at the same time. So you can have a gate that is a not, a nor, and, nand all at the same time which of course takes separate c ...[text shortened]... o squeeze the maximum amount of computing that could be done with both systems working together.

My guess is 20 or more years from now when quantum comes on line, there will be a hybrid classical/quantum computer where each one will have its strengths and will be used to squeeze the maximum amount of computing that could be done with both systems working together.

I think you are right. Although quantum computers will be powerful, they would have several limitations and, in particular, those calculations that can be done in a fraction of a second by classical computers would nearly always be better done by them rather than quantum computers. Only partly because of this, it makes sense to hybridize the two together to get the best of the functionality from each and working together.

Originally posted by sonhouse
The bottom line of it all is the ability of quantum mechanics to do this superposition thing where a particle, say a carbon atom or a photon, can appear to be in two or more places at the same time or can be at several energy levels at the same time. So you can have a gate that is a not, a nor, and, nand all at the same time which of course takes separate c ...[text shortened]... o squeeze the maximum amount of computing that could be done with both systems working together.

its quite fascinating although i do not understand how its possible to be two places at the same time.

Originally posted by robbie carrobie
its quite fascinating although i do not understand how its possible to be two places at the same time.

On a larger scale that you see in your everyday world, it is near-enough true to say it can't. But on the extremely small quantum scale, the same rules don't quite apply in the same way and things can happen that you would know simply don't happen in your every day life on the larger scale.

Before you can understand how a quantum particle can be in two places at the same time, you need to define what is meant by it being in just one place. When the properties of a particle are measured, if they always appear to be within a volume of space V, then we can say it is at place V. Note you cannot measure a tiny quantum particle's position without exploiting another of its properties C other than just its position where C allows it to interact with some other particles or thing to allow detection. But, sometimes, depending on the situation, when we measure the properties of a particle, at least one of its properties may be detected either in a volume of space V1 or a volume of space V2 which are such that there is no overlap between V1 and V2 i.e. there is a gap between them. When this happens, one of the possible simplest interpretation is that it is both at V1 and V2 just before the measurement. Although the simplest interpretation is not necessarily the correct one and thus it must be logically possible for that interpretation to be false, in the minds of many quantum physicists it is the most logical interpretation and, although I am not totally sure this is a fully correct ( i.e logically flawless ) application of Occam's razor, if this is a fully correct application of Occam's razor, they are probably right.

Originally posted by humy
On a larger scale that you see in your everyday world, it is near-enough true to say it can't. But on the extremely small quantum scale, the same rules don't quite apply in the same way and things can happen that you would know simply don't happen in your every day life on the larger scale.

Before you can understand how a quantum particle can be in two place ...[text shortened]... Occam's razor, if this is a fully correct application of Occam's razor, they are probably right.

That makes no sense to my mind. Perhaps its the difficulty of measurement and what scientists think are one and the same particle are two distinct entities or that there is a kind of mirror effect in some dimension that we simply do not know about which gives the impression of being in two places at the same time, i don't know, Perhaps I am simply too stupid to grasp the concept but its amazingly interesting despite that.

Originally posted by robbie carrobie
That makes no sense to my mind. Perhaps its the difficulty of measurement and what scientists think are one and the same particle are two distinct entities or that there is a kind of mirror effect in some dimension that we simply do not know about which gives the impression of being in two places at the same time, i don't know, Perhaps I am simply too stupid to grasp the concept but its amazingly interesting despite that.

Perhaps its the difficulty of measurement

No, the measurement is easy enough to do. It has been done repeatedly and the results consistently show that, in certain set-ups, a property of a particle can sometimes appear to be in multiple locations thus giving the impression, whether true or false, that the particle itself can be in multiple locations.

and what scientists think are one and the same particle are two distinct entities or that there is a kind of mirror effect in some dimension that we simply do not know about which gives the impression of being in two places at the same time,

That assumes far to much. It would be actually far less assumptive to assume they exist in two places at once and avoid assuming both some kind of “mirror effect” and some kind of weird interaction with some mysteries unknown “dimension” that could have such an effect neither of which we currently have any evidence for. Although that certainly doesn't guarantee that less assumptive interpretation is the correct one, until if and when we have evidence to the contrary, we should assume that the 'two places ant once' theory would surely be more likely to be the correct one out of the two interpretations ( assuming one of the two could be correct ) because that is just how Occam's razor works.

However, here I have neglected to mention above other interpretations contrary to the two above ( one being your slightly vague suggestion ) but which aren't so unreasonably assumptive as yours such as:

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

I am uncertain how Occam's razor should be most rationally applied to these alternatives.

Originally posted by robbie carrobie
That makes no sense to my mind. Perhaps its the difficulty of measurement and what scientists think are one and the same particle are two distinct entities or that there is a kind of mirror effect in some dimension that we simply do not know about which gives the impression of being in two places at the same time, i don't know, Perhaps I am simply too stupid to grasp the concept but its amazingly interesting despite that.

I have to point out that although it is confirmed by experimental measurement, a large part of quantum mechanics (except perhaps certain constants) is derivable from mathematics. In other words, many quantum phenomena are predicted by the mathematics and are thus not merely a mistake in the measurements.

Also, trying to visualize it and rationalize it in macro 3D terms is simply never going to be satisfactory - because that is not what it is. Quantum phenomena are often wavelike or particle like because they share common mathematics with those concepts, but they are neither. The secret to understanding quantum mechanics is to accept this. ie you need to accept that an electron is not a particle and is not a wave it is a quantum phenomena which follows certain laws of physics which we can calculate in great detail and to extreme precision and which agrees with experiment to extreme precision.

ok before i appear any more stupid i am going to read quantum mechanics for total noobs, starting here.

http://www.abarim-publications.com/QuantumMechanicsIntroduction.html

wish me luck.