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Author Topic:   universe- why is it here?
sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 14 of 144 (117861)
06-23-2004 8:40 AM
Reply to: Message 1 by tubi417
06-22-2004 1:18 PM


tubi417

Doesn't it seem like there should be some type of higher intelligence to create the universe?

Well, the major stumbling block with that idea is how does an intelligence affect the workings of everything in the universe and leave no trace?Unless you are willing to admit that there is magic in world {and all the sillingness that entails} then the idea of a universe coming into existence on its own as the result of natural outcomes is the most likely explanation.

This message has been edited by sidelined, 06-23-2004 07:47 AM


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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 28 of 144 (122545)
07-07-2004 12:45 AM
Reply to: Message 17 by One_Charred_Wing
07-05-2004 11:51 PM


B2P

The first day I joined this forum(I'll never forget this), somebody quoted some airhead scientist that said, in summary:

"The universe is just too big to be just a stage for a battle between Good and Evil"

Let us get the quote right.

"It doesn't seem to me that this fantastically marvelous universe, this tremendous range of time and space and different kinds of animals, and all the different planets, and all these atoms with all their motions and so on, all this complicated thing can merely be a stage so that God can watch human beings struggle for good and evil, which is the view that religion has.
The stage is too big for the drama."

Yeah, I guess you are right. Richard Feynman,who, at the age of 23 was brought into work on the Los Alamos project constructing the first nuclear weapon.Working as an invaluable part of the greatest collection of intellect ever assembled while his wife lay dying in an Albequerque New Mexico hospital and keeping her spirits up by toying with the military censors through their letters to each other.
From there to teaching at Caltech and eventually to a Nobel Prize in physics in 1964. He also worked on the Commission investigating the space shuttle Challenger disaster.

Yeah the man was an absolute airhead. Just ask any of the one or two people who have read his obscure works such as "The Feynman lectures on Physics" or "The Character of Physical Law" "Feynman Lectures on Computation", "Feynman Lectures on Gravitation." Or Perhaps his unpopular works such as "Surely You're Joking, Mr. Feynman!: Adventures of a Curious Character" or "What Do You Care What Other People Think?: Further Adventures of a Curious Character."
There is also a stage play called QED with Alan Alda playing the part of Feynman.Of course it is probably as lacklustre and boring as the man himself.

Of course you would have to walk a mile in the mans shoes to be able to make such a judgement suach as "Man was that guy full of it!" You will do that in your lifetime right? The neat thing is He would be probably the first to agree with you .As a last retort to your post I thought I would give just a tiny sample of the airhead himself.

A poet once said, "The whole universe is in a glass of wine." We will probably never know in what sense he meant that, for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough we see the entire universe. There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflection in the glass, and our imagination adds the atoms. The glass is a distillation of the earth's rocks, and in its composition we see the secrets of the universe's age, and the evolution of stars. What strange array of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization: all life is fermentation. Nobody can discover the chemistry of wine without discovering, as did Louis Pasteur, the cause of much disease. How vivid is the claret, pressing its existance into the consciousness that watches it! If our small minds, for some convenience, divide this glass of wine, this universe, into parts - physics, biology, geology, astronomy, psychology, and so on - remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let it give us one more final pleasure: drink it and forget it all!"

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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 30 of 144 (122564)
07-07-2004 2:23 AM
Reply to: Message 29 by jar
07-07-2004 12:49 AM


Re: One of my favorite Feynman stories
jar

As I recall he really bugged his sister when one-upping her with the Chinese.I guess he made up it in later years by allowing her the aurora borealis by promising never to apply his powerful mind to working on it,kept that promise too, apparently. She went on to become a senior scientist at Nasa's Jet Propulsion Laboratory.


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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 37 of 144 (122818)
07-07-2004 8:44 PM
Reply to: Message 36 by One_Charred_Wing
07-07-2004 8:27 PM


Re: Richard Feynman is a woozle
B2P

and honestly, I want a bumpersticker that says that. No offense against scientists in general so PLEASE DON'T start calling me a fundie who is biased against science or anything, but what you showed me just reinforced my observations that scientists aren't philosophers

Good bloody thing. No real progress would ever be made otherwise.


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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 44 of 144 (122905)
07-08-2004 9:15 AM
Reply to: Message 41 by coffee_addict
07-08-2004 1:20 AM


Re: Richard Feynman is a woozle
Lam

Sorry Lam I should have placed a smiley face at the end of that sentence. I do believe that science is hardly non-philisophical but that scientists do not concern themselves with the things that philosophers do.When science discovers phiosophers argue the ramifications of the discovery like tourists following the explorers.
They seldom pick up on the just how much a change of the view of the world is involved in the discovery of new knowledge.

Of course scientists are no better than phlosophers as people in their relations with the world.


You see a book lying on a table. You know there's a force due to gravity acting on that book. If you take that force (on the book and due to gravity) as the "action," what then is the "reaction" as required by Newton's third law?

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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 52 of 144 (123110)
07-08-2004 8:51 PM
Reply to: Message 48 by One_Charred_Wing
07-08-2004 6:58 PM


Re: Richard Feynman is a woozle
B2P

Knowledge is raw, nuetral information. It can potentially create wonderful things, like vaccine and electric cars. But it can equally well create terrible things like poision gas and atom boms. Wisdom incompasses the understanding of right and wrong, adding the 'why' to all these incredible discoveries; without it we'd have long made nuclear winter.

Just to clear up something here.Are you stating that knowledge can create poison gas or atomic bombs vaccine and electric cars or are you meaning to say that the people who employ knowledge, which you state is neutral,can create terrible or wonderful things.

Again I must disagree in the discernment of what constitutes good or evil.We can imagine contexts where the poison gas or atomic bombs may indeed be "good".

Philosophers who engage in science work need to understand that science well enough to take a problem applicable to that science and correctly work it out before they may comment on the philisophical ramifications of the knowledge gained.

By the same token your comment here directed at the deceased Richard Feynman,

I've said it to a lot of people before, and I'll be more than happy to say it again(directed at the proverbial Feynman, not you ofcourse):

NO AMOUNT OF SCIENTIFIC KNOWLEDGE CAN CHANGE THE FACT THAT YOUR PHILOSOPHY IS FULL OF SHIT

is a puzzle to me as you are generalizing on his philosophy without pointing out what his philosophy is.

I apologize to you as well for my previous statement and for using Lam as proxy to do so earlier.I had a feeling that you might tag me on that.


You see a book lying on a table. You know there's a force due to gravity acting on that book. If you take that force (on the book and due to gravity) as the "action," what then is the "reaction" as required by Newton's third law?

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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 54 of 144 (123292)
07-09-2004 8:58 AM
Reply to: Message 53 by One_Charred_Wing
07-09-2004 2:48 AM


Re: Richard Feynman is a woozle
B2P

but the quote you gave me did nothing to change my opinion that the philosophical point he gave is not a good one.

Man was that guy full of it! No amount of space could be big enough for there to not be evil, and some good to challenge it. And since disorder increases with time naturally that means intelligent life will inevitably become corrupt with time. So after all this time, you'd think we would have killed eachother off. But for some reason this 'disorder' keeps getting supressed somehow. Now if that's not something to ponder about I don't know what is; so in short I believe this universe is a stage for something huge, and who wouldn't want to be a part of something that big? And besides, too bad! They live in it .

and Feynman's quote

"It doesn't seem to me that this fantastically marvelous universe, this tremendous range of time and space and different kinds of animals, and all the different planets, and all these atoms with all their motions and so on, all this complicated thing can merely be a stage so that God can watch human beings struggle for good and evil, which is the view that religion has.
The stage is too big for the drama."

The stage is too big for the drama?

That is what I am curious about.I get the impression that you do not understand just how much space he was talking about.The entire Earth is less than a drop of water in the oceans of our planet in comparison to the amount of space that is simply not being utilized by God in His drama.Much of that space is not even accesible to us and plays no part.

Your opinion is of course your own and you need not defend it but I am really curious, as I think that we learn best from those with a different point of view.

This message has been edited by sidelined, 07-09-2004 07:59 AM


You see a book lying on a table. You know there's a force due to gravity acting on that book. If you take that force (on the book and due to gravity) as the "action," what then is the "reaction" as required by Newton's third law?

This message is a reply to:
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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 56 of 144 (124208)
07-13-2004 8:48 AM
Reply to: Message 55 by One_Charred_Wing
07-09-2004 7:13 PM


Re: Richard Feynman is a woozle
B2P

I really doubt this 'drama' as we're calling it will all take place on earth; there's a great big universe out there and if God is any fun he'll allow us to take the battle to the next level, because divine space battles rule.

You really like your video games don't you? Fighting on universal scale would be boring in the exteme.Fighting in real combat is also obviously not the ambition of a sane mind but regardless of that having to plod along at the limits of speed that are imposed on us by the universe would make a fight even within our local star system futile.

Anyhow we are way off topic and I do suppose I might start a related topic to debate these things.


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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 80 of 144 (135888)
08-21-2004 3:57 AM
Reply to: Message 74 by General Nazort
08-20-2004 12:42 AM


General Nazort

Examples of things that seem to happen for no reason at all, things acribed to "chance," are just where we do not have a full understanding of everything involved

An atom decays in a certain, predictable way, we are just not able to predict it yet.

I don't see how something can "just decay." The laws of physics contradict this

Sorry to let you know this but the last physicist was Einstein who believed the universe was ultimately decipherable and he was never able to break the success of quantum mechanics down to a level where we could determine a underlying reality.It has never been done and as it stands the laws of nature prohibit knowledge beyond a certain level by her very structure.This website does a great job of condensing the history of the foundation for quantum mechanics.

http://books.nap.edu/books/0309076412/html/1.html#pagetop

Uncertainty is woven into the fabric of the world.


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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 85 of 144 (136137)
08-22-2004 5:09 PM
Reply to: Message 84 by Darwin Storm
08-22-2004 2:49 PM


Re: Belles Inequality
Darwin Storm

If you think that is the end of the story check this out.

The idea that the quantum world is disrupted by those who observe it has frustrated researchers for almost 80 years. Goodbye to all that, says Michael Brooks

WE HAVE always been aware that quantum stuff moves in mysterious ways. A quantum particle such as an electron can spin clockwise and anticlockwise at the same time, for example, or exist simultaneously in two places. We've also known that these strange "superpositions" are extremely fragile. Indeed, it is a tenet of quantum theory that as soon as anyone tries to observe a superposition, it collapses back to some kind of normality. Make a measurement of, say, an electron spinning both ways at once and the electron appears to have just one spin.

That is why Schrödinger's famous cat can only be both alive and dead at the same time in its box so long as no one looks inside. Lifting the lid forces the cat to either live or die. And so this mysterious quantum world has remained impossible to explore. Until now, that is.

Yakir Aharonov, an influential physicist at Tel Aviv University and the University of South Carolina, believes he has discovered a way to observe the quantum world without destroying superpositions. This is a stunning claim and flies in the face of 80 years of teaching about quantum theory. But Aharonov says a technique he has invented, called "weak measurement", shows that looking at something doesn't have to change it. "Weak measurement finds what is there without disturbing it," he says.

Although Aharonov has been working on weak measurement for 15 years, his confidence has recently grown enormously. Last year he published a paper showing that weak measurement can give us new insight into a previously inexplicable paradox in quantum mechanics ( Physics Letters A , vol 301, p 130). The result of this work is "strange and surprising", Aharonov says, but shows quantum theory to be logical and self-consistent. Weak measurement, he believes, will be the tool that finally opens up the weirdness of quantum theory for inspection.

The paradox in question is a thought experiment described in 1992 by Lucien Hardy, then at the University of Oxford, which shows how quantum theory makes a nonsense of the interaction between matter and anti-matter. First Hardy considered a Mach-Zender interferometer, an instrument in which a quantum particle hits a half-silvered mirror. This sends it into a superposition of states, in that it travels down two separate arms at once.

The interferometer later reunites the two paths, although what happens then depends on what happened en route. The arms of the interferometer meet at another half-silvered mirror, which is arranged so that if the particle has had an undisturbed journey - that is, it doesn't encounter any other particles or fields - it is collected in a detector "C". But if something disturbs the particle while it is on its way through the interferometer, it may arrive at a second detector, "D".

Hardy imagined two such interferometers positioned so that one arm of the first overlaps with one arm of the second (see Diagram) . Then he imagined sending a positron - the antiparticle of an electron - through one interferometer, and an electron through the other at the same time. If the two particles travel along the overlapping arms they should meet in an "annihilation region" and destroy one another.

Hardy showed that something much stranger happens: in rare cases, quantum theory predicts that both D detectors could click simultaneously. Somehow both particle and antiparticle could disturb, yet fail to annihilate, each other in the overlapping arms.

The situation arises because quantum theory deals with probabilities amassed from the multiple existences of particles. Since the particles can simultaneously be in and not in the overlapping arms, the probabilistic nature of quantum theory allows an improbable - yet possible - outcome that makes no sense. This is Hardy's paradox.

In the decade since Hardy described it, people have "resolved" the paradox by saying that the thought experiment doesn't correspond to any possible real experiment, and is therefore meaningless. The only way to find out what really happens to the particles in the experiment would be to measure their routes, rather than simply inferring them from the final result. But as soon as a particle detector is placed in any of the paths, standard quantum theory says the particles will be disturbed, guaranteeing that the D detectors will fire. So you can no longer infer the particles' positions: the paradox is lost.

"The general attitude is 'since the paradox disappears when measurements are performed, the whole paradox is a red herring and doesn't deserve much attention'," says Sandu Popescu of the University of Bristol and Hewlett-Packard Labs, Bristol. But Popescu and Aharonov think otherwise. Working with Tel Aviv Unversity's Benni Rezni, Alonso Botero of Texas A&M University, and Jeff Tollaksen of Boston University, they have devised a modified version of Hardy's thought experiment that could be performed in a lab. By their calculations, the paradox will still exist, but because the experiment can actually be done, it means the paradox cannot be dismissed as abstract reasoning: it must be an objective truth of quantum theory.

The "weak measurement" technique they propose exploits quantum uncertainty - the fact that in any quantum system there is always an intrinsic uncertainty about properties such as a particle's position and energy. Aharonov's quantum detector is so weakly linked to the experiment that any measurement moves the detector's "pointer" by less than the level of uncertainty. In return, the detector has an imperceptible impact on the experiment. Astonishingly, this means any superpositions are preserved.

There is a price to pay for these delicate readings, however: they are extraordinarily inaccurate. But while this might appear to make the whole process pointless, Aharonov has calculated that when repeated many times, the average of these measurements approximates to the true value of the thing being measured.

Imagine a set of scales designed to measure the weight of an electron. In a weak measurement, quantum uncertainty means that the position of the scales' pointer will always be uncertain by a small amount, and the size of that discrepancy will be larger than the weight of the electron. This makes it impossible to say for certain what an electron weighs. But if billions of electrons land one at a time on the scales, the average of all the measurements will reveal the weight.

Of course, if it is not clear that an electron is on the scales or not, taking an average of all the readings won't give a true indication of its weight. The average will be skewed to a lower value by the occasions when no electron was present. But Aharonov and Popescu get round this problem: they know which runs of the experiment make both D detectors click and so can choose which measurements to throw into their average, and which to ignore.

In their thought experiment, Aharonov and Popescu "post-select" the results: they focus on just the paradoxical incidents when both D detectors click. The weak measurements then build up a picture of what is going on, all without disturbing the system. The reward is a result that presents the paradox in a fully logical, self-consistent way.

The apparatus in their thought experiment includes an array of detectors that make one of two different types of weak measurement. One type counts the number of electrons or positrons that pass along each arm. This could be a gravitational field detector fixed strongly in place so the particle's presence transfers almost no momentum. The second weak measurement comes from "pair detectors" that can record an electron and a positron passing simultaneously past two separate points. These "pairs" might be measured by two boxes connected by a rigid spring - the attraction between a pair would slightly compress it. The exact methods are not as important as the fact that they could be physically performed in the lab. All these weak, inaccurate results are recorded only when both D detectors click, and the results are then averaged over many runs of the experiment.

With the mental apparatus assembled, the physicists "run" the experiment. The results are predictable - at least in quantum terms. First they calculate the number of electrons passing through the annihilation region every time both D detectors click. The average is 1. The number of positrons passing through the region is also 1. The same measurements made for the non-overlapping arms of the interferometer give 0. This is exactly what would be expected with both D detectors clicking: both particles must have been in the annihilation region for them to disturb each other. So why didn't they annihilate? Another calculation reveals a rather puzzling answer to this question. The pair detectors show that the number of electron-positron pairs in the annihilation region is 0.

Other pair detectors reveal even stranger results. One indicates the presence of an electron in the annihilation region at the same time as a positron travels down the non-overlapping arm. Another shows a positron in the annihilation region while an electron is in the non-overlapping arm.

So with weak measurements, the paradox remains: we have an electron and a positron disturbing each other in the annihilation zone, yet pair measurements tell us they were not there together, so could not have disturbed each other. But there's now an additional difficulty: the results imply that there are two pairs of particles in the apparatus at the same time. And we know that's not true. It seemed like a fundamental flaw - until, that is, Aharonov and Popescu looked at a final pair-measuring device in the non-overlapping arms of the interferometer. The reading there was -1. Somehow, there was a "negative presence".

Aharonov says that when he first saw the negative number come out of the pair measurement, he was rather taken aback. Nobody had seen anything like it before. "It looks impossible. But then I realised it was the only way to see it. It's beautiful."

What exactly a -1 result means is still up for grabs, but Aharonov and Popescu believe they have shown that there is a way to carry out experiments on the counter-intuitive predictions of quantum theory without destroying all the interesting results. A single quantum particle could have measurable effects on physical systems in two places at once, for instance. Indeed, Aharonov and Popescu say, when you get a look inside, quantum theory is even more bizarre than we thought. Quantum particles can assume far more complex identities than simply being in two places at once: pairs of particles are fundamentally different from single particles and they can assume a negative presence.

And the fact that weak measurements transform the paradox from a mere technicality into an unavoidable truth suggests that they could provide a springboard for new understanding in quantum mechanics. "It shows there are extraordinary things within ordinary quantum mechanics," Popescu says. The negative presence result might be just the tip of the iceberg: every paradox in quantum theory may simply be a manifestation of other strange behaviours of quantum objects that we have not yet detected - or even thought of. "Many of the well-known paradoxes of quantum mechanics have properties like this," Popescu says.

From thought to reality

Klaus Mølmer of Aarhus University in Denmark was initially sceptical about weak measurement, but his own examination of Aharonov and Popescu's work has convinced him it has to be taken seriously. He even thinks he knows how to demonstrate it in a real experiment. It could even be done now, since it exploits the same techniques that quantum computing researchers use (see "Paradox lost") .

Hardy, now at Ontario's Perimeter Institute, is also impressed by Aharonov and Popescu's work, but questions its meaning. "In spite of the consistency with which the apparatus gives these negative readings, it is quite a jump to infer that there really are a negative number of particles," he says. Instead, Hardy suggests, it might just be a form of error. But, he concedes, there is definitely a case to answer because the apparatus consistently gives the same error - a negative number of particles whenever both D detectors click. "This error is consistent with what might otherwise be regarded as some kind of naive reasoning about otherwise paradoxical situations."

While Hardy remains noncommittal about weak measurements, Popescu insists that there's nothing unusual about them. They are not a magic trick, and not even a convenient "interpretation" of quantum mechanics. "They are a particular type of measurement, and their results are just ordinary experimental results," he says. "Unusual experimental results, to be sure, but not fiction."

Aharonov admits that his ideas about weak measurements remain "widely unaccepted", but he's not cowed by that. Everyone will talk in terms of weak measurements in the future, he says; some are already learning the language.

Raymond Chiao of the University of California at Berkeley and Aephraim Steinberg of the University of Toronto, for example, are looking at weak measurement as a way to explain photon tunnelling. It is widely accepted that quantum objects such as atoms and photons can "tunnel" through barriers that they don't strictly have enough energy to get over. Experiments show that photons really can do this - and at speeds greater than the speed of light. Chiao and Steinberg, who performed the first experiments to demonstrate photon tunnelling, are exploring the idea that, since the photon's chances of accomplishing this feat are tiny for a wide barrier, their experiment might have been a post-selected weak measurement, allowing them to observe a strange quantum event that defies ordinary logic. It may involve negative energies or even negative time. They are exploring these possibilities in further experiments that use weak measurements.

Howard Wiseman of Griffith University in Queensland, Australia, also believes weak measurements can help shed light on strange quantum phenomena. In a forthcoming paper in Physics Letters A , Wiseman shows how weak measurement and negative presence can interpret double-slit interferometer experiments. Fire an electron at a pair of parallel slits and, if left undisturbed, the electron produces a pattern on a screen behind the slits that is created by interference between two electron states in superposition.

Some have suggested it might be possible to determine which slit the electron went through to find out what is really going on with the electron's simultaneous wave and particle existence. But this has generally been deemed impossible because any attempt to look at the electron gives it extra momentum, which affects the outcome and washes away the interference pattern. But Wiseman has shown that weak measurement reveals that such momenta can take on a negative value, giving a net momentum of 0 to the electron and letting researchers determine which slit the electron went through. It is, he says, possible to do this with existing technology.

Mølmer's experience with translating weak measurements into a real lab experiment makes him think that most of what has been done to date with quantum systems employs weak measurement - physicists just haven't realised it. He now believes weak measurements might even have practical repercussions. They could, for example, expose flaws in quantum cryptography, in which disturbance caused by measurement is supposed to prevent eavesdroppers decoding messages. "A weak measurement used by an eavesdropper could be an interesting strategy," Mølmer says.

Whatever the implications - and Popescu and Aharonov are sure they've only begun to scratch the surface - a new door has opened. Weak measurement should give us a view inside the processes of quantum mechanics that we once thought impossible. It has already uncovered a negative presence that we never knew existed, and there could be plenty more surprises waiting to be found.

Eventually, Aharonov believes, weak measurement may dispel all our present notions of the weirdness of the quantum world. Aharonov claims that when the Nobel laureate Richard Feynman famously pronounced that we can never truly comprehend quantum mechanics, he was "too hasty". "I think people will remove the mystery that Feynman said could never be removed," he says. "You should never say never."

No doubt that the weirdness of quantum mechanics has only just begun. We live in interesting times.


This message is a reply to:
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sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 133 of 144 (139095)
09-02-2004 8:31 AM
Reply to: Message 132 by Tony650
09-02-2004 5:12 AM


Tony650

Ok, so asking what is "below the Planck length" is kind of like asking what was "before the big bang.

In a sense this is correct but what actually occurs is this. A quanta is the smallest unit of energy that exists.You cannot have a half quanta or any fraction of it.In trying to make a measurement of the quanta you cannot tell whether the quanta you are measuring come sfrom that which you are observing or from the instrument you are using to observe the quanta.This is by the way the origin of the "observer is the observed" phrase.This does not mean that they are one and the same but that there can be no distinction made between the two of them.

Check out this webpage to get a perspective on the history behind the problems classical mechanics had and how they were solved by quantum mechanics.
http://www.nap.edu/books/0309076412/html/

This message has been edited by sidelined, 09-02-2004 07:31 AM


This message is a reply to:
 Message 132 by Tony650, posted 09-02-2004 5:12 AM Tony650 has replied

Replies to this message:
 Message 136 by Tony650, posted 09-03-2004 1:50 AM sidelined has replied

  
sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 138 of 144 (139799)
09-04-2004 12:57 AM
Reply to: Message 86 by Darwin Storm
08-22-2004 5:56 PM


Re: Belles Inequality
Darwin Storm

I am sorry I did not reply to this. I cannot track down the precise paper however there are several that you may scope out. These are from the University of Tel Aviv at this website

http://www.tau.ac.il/~quantum/publicat/publicat.html#weak-meas

Emergence of Weak Values
Lev Vaidman
in Quantum Interferometry, F. De Martini, G.Denardo, Y. Shih (eds.) (VCH Publishers, Weinheim, 1997), 485
quant-ph/9607023

Adiabatic Measurements on Metastable Systems
Y. Aharonov, S. Massar, S. Popescu, J. Tollaksen and L. Vaidman
Phys. Rev. Lett. 77, 983 (1996)
quant-ph/9602011

Weak-Measurement Elements of Reality
Lev Vaidman
Found. Phys. 26, 895 (1996)
quant-ph/9601005

There Is No Classical Analog of a Quantum Time-Translation Machine
Lev Vaidman
Phys. Rev. A 52, 4297 (1995)
quant-ph/9502004

Weak Measurements
Lev Vaidman
in Advances in Quantum Phenomena, E. Beltrametti and J.M. Levy-Leblond eds., NATO ASI Series B: Physics Vol. 347 (Plenum Press, NY, 1995), 357
hep-th/9408154

Negative Kinetic Energy Between Past and Future State Vectors
Daniel Rohrlich, Yakir Aharonov, Sandu Popescu and Lev Vaidman
Ann. NY Acad. Sci. 755, 394 (1995)
cond-mat/9406116

Measurements, Errors, and Negative Kinetic Energy
Y. Aharonov, S. Popescu, D. Rohrlich and L. Vaidman
Phys. Rev. A 48, 4084 (1993)
hep-th/9305075

Measurement of Negative Kinetic Energy of Tunneling Particles
Y. Aharonov, S. Popescu, D. Rohrlich and L. Vaidman
Jap. Jour. App. Phys. Series 9, 41 (1993)

A Quantum Time Machine
L. Vaidman
Found. Phys. 21, 947 (1991)

Complete Description of a Quantum System at a Given Time
Y. Aharonov and L. Vaidman
Jour. Phys. A 24, 2315 (1991)

Superpositions of Time Evolutions of a Quantum System and a Quantum Time-Translation Machine
Y. Aharonov, J. Anandan, S. Popescu and L. Vaidman
Phys. Rev. Lett. 64, 2965 (1990)

Weak Measurement of Photon Polarization
J.M. Knight and L. Vaidman
Phys. Lett. A 143, 357 (1990)

Properties of a Quantum System During the Time Interval Between Two Measurements
Y. Aharonov and L. Vaidman
Phys. Rev. A 41, 11 (1990)

Reply to Leggett and Peres on "How the result..."
Y. Aharonov and L. Vaidman
Phys. Rev. Lett. 62, 2327 (1989)

A New Characteristic of a Quantum System Between Two Measurements - a Weak Value
Y. Aharonov and L. Vaidman
in Bell's Theorem, Quantum Theory and Conceptions of the Universe, M. Kafatos (ed.), 17 (1989)

How the Result of Measurement of a Component of the Spin of a Spin-1/2 Particle Can Turn Out to Be 100
Y. Aharonov, D. Albert and L. Vaidman
Phys. Rev. Lett. 60, 1351 (1988)

Surprising Quantum Effects
Y. Aharonov, D. Albert, A. Casher and L. Vaidman
Phys. Lett. A 124, 199 (1987)

How to Ascertain the Values of Sigma_x, Sigma_y, and Sigma_z of a Spin-1/2 Particle
L. Vaidman, Y. Aharonov and D. Albert
Phys. Rev. Lett. 58, 1385 (1987)


This message is a reply to:
 Message 86 by Darwin Storm, posted 08-22-2004 5:56 PM Darwin Storm has taken no action

  
sidelined
Member (Idle past 5178 days)
Posts: 3435
From: Edmonton Alberta Canada
Joined: 08-30-2003


Message 141 of 144 (140306)
09-06-2004 11:03 AM
Reply to: Message 136 by Tony650
09-03-2004 1:50 AM


Tony650

I think I get what you're saying. One question, though; will this problem always be inherent in our equipment/techniques or is it something that could be eliminated as our equipment/techniques become more refined?

The problem lies in the fact that our instruments sre made of the same stuff as that which we are trying to study. Any limitations on the subject are also a limitation on the investigating instrument.


This message is a reply to:
 Message 136 by Tony650, posted 09-03-2004 1:50 AM Tony650 has replied

Replies to this message:
 Message 143 by Tony650, posted 09-07-2004 12:59 PM sidelined has taken no action

  
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