From: Janusz 15/06/99 0:11:14 Subject: Quantum physics post id: 17743 Quantum physics seem to defy some laws of classical physics..., how much do we know about it to actually apply it to every day life or are we a lot further from applying it . The reason i ask is that i heard of quantum computers and electronic devices such as non electronic transmission quantum dot cellular automata. When are us consumers be able to use such things on a regular basis. This also creates a new way of thinking behind the way we make things. From: Terry Frankcombe 15/06/99 0:37:12 Subject: re: Quantum physics post id: 17745 What is non electronic transmission quantum dot cellular automata? I think I understand those words, but those meanings don't mean anything when put together like this. From: Janusz 15/06/99 0:49:38 Subject: re: Quantum physics post id: 17746 That collection of words you recognise are suposed to be a tiny structure in which an electron can be confined and then arranged into cells through somekind of microelectronic tecniques to create logic gates. basically arranging electrons to form gates thus reducing the size of transistors inside computer processors. From: Spun 15/06/99 10:21:57 Subject: re: Quantum physics post id: 17771 Janusz do you have a CD player? If so then you are already using a product that relies on Quantum Mechanics - the Laser. From: Chris (Avatar) 15/06/99 11:32:57 Subject: re: Quantum physics post id: 17786 Quantum mechanics "averages out" into everyday classical mechanics at our everyday scale. The effects normally associated with "quantum weirdness" only become apparent at the quantum scale (ie the scale of quantum particles). Your observation that QM defies classical laws would probably more correctly be put that QM is the way the world "is" at the quantum scale, and that it averages out into solid relationships at our everyday scale which we can approximate with classical laws. Spun is right about the applications of quantum technology. It's all about you everyday (it has also helped shape history in some less attractive ways...). As far as quantum processing is concerned, there has been a lot of work into quantum or "Feynman" processors. The quantum logic gates you mention, when combined with parallel processing, bypass the restrictions of micro-electronic circuitry. Hope this helps! Chris From: Martin B 15/06/99 11:53:51 Subject: re: Quantum physics post id: 17791 Quantum physics is very different to the laws of classical physics. It is also very well tested - and has passed every time. Quantum physics forms the basis of much technology such as lasers and semiconductor electronics. Quantum physics first arose through a consideration of the behaviour of matter on a microscopic scale. At this scale the laws of classical physics proved completely inadequate as they were unable to answer questions like "what stops the electrons from being pulled into the atomic nucleus?" On a larger scale, such as we see around us, we are no longer concerned with the behaviour of individual particles, but with the average behaviour of large numbers of particles. It can be shown that these averages behave in exactly the way that the classical laws of physics predict. Thus quantum mechanics is the 'true' theory while the classical laws are an approximation for systems of large particles (like you and me) Quantum computers as was discussed in an earlier thread are a long way off practical implementation and so we cannot expect them in a laboratory, let alone a supermarket shelf for decades to come. From: janusz 17/06/99 1:27:41 Subject: re: Quantum physics post id: 18137 I relise that QP is all around in every day life , it shaped the history etc. what i would like to know is how much do we know about it to actually implement the theory directly for our benefit.Such that we are implementing it into computers therefore we must know some thing about it .For exapmle; A cave man once new about , has seen and interacted with fire- right , then he (the cave man) decided to learn how to use it to his advantage . So i want to know how much does man know about QP to directly use to his advantage? From: Dr. Ed G (Avatar) 17/06/99 3:26:38 Subject: re: Quantum physics post id: 18142 ALL semiconductor transistors operate directly from the principles of quantum mechanics... without quantum mechanics, you can't understand how a transistor works (let alone easily make a better one). Ipso facto every time you use anything from a transistor radio, to a TV, to a PC, you are reaping the benefits of the theories of quantum mechanics. Now, you can teach an Engineering student how to design a circuit (/radio/TV/computer) using transistors without their having to know anything about quantum mechnics (just the end equations that are derived from quantum mechanics), but in order to understand the operation of the operation of the actual transistors themselves, you need quantum mechanics - although you don't need it at the level that you need to understand more esoteric devices such as quantum dots, or the family of things proposed for doing what is known as quantum computing (which IS different from normal digital computing). Soupie twist, Ed G. From: Chris W (Plebeian) 17/06/99 8:58:50 Subject: re: Quantum physics post id: 18150 My electronic engineering subjects covered transistor operation right down into quantum effects. They are especially important to know about if you work at the extremes transistor operation. From: Dr. Ed G (Avatar) 18/06/99 1:52:53 Subject: re: Quantum physics post id: 18479 Certainly. Sorry, I didn't mean they don't teach it (especially as you say when it comes to designing at the limits of transistors themselves), it's just that you don't need to know the details if you're just doing circuit design. Indeed, the main project I'm currently working on for Philips is the fabrication of high speed amorphous silicon based transistors in which quantum tunneling and reflection in the base region is critical to their operation - but thankfully the level of QM theory needed is nothing like what you would need for, say, quantum dots, or degenerate electron gases, or the like, or I suspect my brain might explode (really, I'm a bear of very little brain :-) Soupie twist, Ed G. This forum is un-moderated. The views and opinions expressed are those of the individual poster and not the ABC. 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