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quantum leap

Posted: Mon Jul 25, 2005 5:04 am
by Ken Greenwald
During the course of our discussion of"calibrated"; Janus word?, it was mentioned that QUANTUM was a Janus word. I protested that it wasn’t, based on my familiarity with the word in quantum mechanics. However, it was pointed out to me how the word has taken on new meaning as a result of its use in the expression ‘QUANTUM LEAP.’ And in light of that new meaning and a lack of understanding of what the original 'quantum' really means (<:), I agree that ‘quantum’ could be construed to be a Janus word.

I believe that this topic is interesting enough to warrant its own posting, and below I have reproduced what has already been said on the subject:

In quantum ( a Janus word ) physics, the instrucment used for observation may be altered by that which is observed. Obviously Groucho intuitively understood this to be a possibility.


Che, I noticed these blunders of yours some time ago, but just discovered my sticky note reminding me to post a reply.

In my humble opinion, I think you ought to stick to your day job and hold off making erroneous pontifications on quantum mechanics! (<)

1) You’ve actually got the above story backwards. In quantum physics it is not the instrument that is altered by that which is observed, it is that which is observed is altered by the instrument. When an observation is made by an instrument/observer, the wave function (a probabilistic mathematical description of that which is being observed), which is a superposition of simultaneous states (all of the existing quantum possibilities), suddenly collapses down to a single state (the result of the observation caused by the instrument/observer) – the famous ‘collapse of the wave function’ (think Schrödinger’s Cat, if you happen to know what that is) – and that is the reading the observer sees.

2) A Janus word, as far as I am aware, is defined as a word which is its own antonym (see Janus words (antagonyms, contronyms). The OED defines quantum (in physics) as follows:
<“A minimum amount of a physical quantity which can exist and by multiples of which changes in the quantity occur.”>
This is the basic definition of quantum, but, as all of us quantum types know, this could be a) A discrete quantity of electromagnetic energy equal to Planck's constant times the frequency of the associated radiation. 2) A discrete amount of any other physical quantity (spin, angular momentum, magnetic moment, electric charge, etc.).

However, the fact that a quantum could be a discrete quantity of electromagnetic radiation or a discrete quantity of charge, for example, doesn’t make ‘quantum’ a Janus word. And the wave-particle duality (the fact that all phenomena – electrons, atoms, light, sound, etc. – have both particle and wave characteristics) doesn’t make ‘quantum’ a Janus word. In fact, I don’t see anything that could make ‘quantum’ a Janus word. In order to be a Janus word ‘quantum’ must be its own antonym – the antonym of ‘A minimum amount of a physical quantity which can exist and by multiples of which changes in the quantity occur.’ And what would that be?? – A maximum amount of physical quantity which can exist and by non-multiples of which changes in the quantity occur?, or . . . . . . ? So, forget it – ‘quantum’ ain’t its own antonym. But good shot at trying to make it appear that you know quantum physics by tossing around some buzzwords and related statements, when what you say seems to indicate that you really don’t! Why not try tossing about some words in art, for example? Maybe you’ll have better luck, and I probably wont be able to catch your indiscretions! (<:)

Ken G – July 24, 2005

Ken, apart from your justified correction concerning the physical aspects, I suppose what Che means by "Janus word" in this context is the fact that most people not involved in physics think the term 'quantum leap' means a huge leap, while in reality it means the exact opposite. One might say it has become sort of a Janus word by wrong usage and lack of knowledge.

Hans Joerg Rohtenberger

In a sense, however, "quantum" is a Janus word. Formerly a quantum change represented the smallest possible exchange of energy. But in popular jargon a "quantum leap" is a very large change

Oops there, Haro, you beat me to it

Dale Hileman

A quantum leap comes from a specific term in physics which refers to a sudden, abrupt change of a particle from one quantum state or level to the next with no states in between, so that while in one sense it is the smallest change possible, it is also a major change that happens all at once - Imagine you are sitting stopped in your car and then are instantly going one mile an hour, while it's a very small change, you've just experienced an acceleration (change in velocity) during which no time passed which could be considered an infinite amount (dividing by zero).

Russ Cable

quantum leap

Posted: Mon Jul 25, 2005 5:18 am
by Ken Greenwald
Hans Joerg and Dale, That’s interesting and I can see that point of view of ‘quantum’ being a Janus word, although it had never crossed my mind. I suppose I never thought of the adjective quantum or quantized as having anything to do with size. In my mind ‘quantum’ implies ‘discrete’ as opposed to ‘continuous,’ having little to do with big or small. A ‘quantum jump or leap or transition’ in physics (as Russ explained) is just an abrupt transition of a system from one of its discrete stationary states to another, as, for example, the fall of an electron in an atom to an orbit of lower energy, or the excitation into a higher one (the principle upon which the laser is based). But in atomic physics this is all relative, since various quantum leaps may be considered big or small depending on what they are being compared to.

However, without a doubt, now that it has been pointed out to me, many folks have taken the adjective QUANTUM to mean ‘sudden and large’ as used in the expression QUANTUM LEAP, a sudden and large advance.

This is interesting and I decided to take a look and see what I could find on the evolution of this originally quantum mechanical phrase.

QUANTUM ‘first appeared in print in 1619 and meant 'sum or quantity’ and was borrowed from Latin ‘quantum,’ how much, neuter of ‘quantus,’ how great. Max Planck introduced the idea of a ‘quantum’ in physics as a unit of energy in 1900, but did not specifically use the word. The first use of the word quantum in physics was by Kelvin in 1902 (see quote), but in reference to a unit of charge and its multiples. Einstein introduced the concept of light QUANTA in 1905. However, the word QUANTUM itself first appeared in print in 1910 (see quote). And for the curious, the term QUANTUM MECHANICS first appeared in 1922 as a probabilistic theory of motion and interaction, especially of sub-atomic particles, as distinguished from ‘classical mechanics,’ a deterministic theory based on Newton’s laws of motion, etc. and which, in general, is applicable to the macroscopic as opposed to the microscopic world.

I found the expression QUANTUM LEAP in several sources (OED, Brewer’s Dictionary of Modern Phrase & Fable Ayto’s 20th Century Word’s) all of which said that its first use as a large leap forward, and outside of the world of quantum mechanics, was in the 1970 (see quote below). However, I’ve traced the expression further back and, in fact, to the evolutionary theorist who coined it (see quote 1944, 1961, 1983 quotes below).

Brewer’s Dictionary of Modern Phrase and Fable:

QUANTUM LEAP: A sudden large advance; a spectacular leap forward. The term evolved in the 1970s as a variant of the older ‘quantum jump,’ which properly and originally described the abrupt transition of an electron, atom, or molecule from one energy state to another. Such a ‘leap’ is not of course large in the traditional sense, however, spectacular it may have seemed to physicists. The present sense may have come about through the wrong association of ‘quantum’ with ‘quantity.’
<1910 “The absorption of the corresponding light-QUANTUM.”—‘Science Abstracts A, XIII, page 556>

<1922 “The spectrum theory is far the most important branch of the quantum theory, as it has led and is still leading to extensions of QUANTUM MECHANICS.”—‘Report of the British Association for the Advancement of Science, 1921, page 473>

<1924 “The firsts column of table I gives the substance experimented on, the second column gives the quantum numbers designating the QUANTUM JUMP.”—‘Proceedings of the National Academy of Sciences, Vol. 19, No. 3, 15 March, page 85> [[quantum mechanics]]

<1930 “First, we may refer the arbitrary character of a single ultimate physical event, such as a QUANTUM LEAP, to the arbitrary character of the whole universe of which the single event is a part, . . .”—‘The Science of Life,’ in the ‘Journal of Philosophy,’ Vol. 27, No. 16, July, page 429> [[quantum mechanics]]

<1944 “QUANTUM LEAP.” “Quantum evolution” in ‘Tempo and Mode in Evolution’ by George G. Simpson> [[the phrase coined to mean a large leap forward taking the idea from quantum mechanics]]>

<1961 “. . . a careful attention to the dicta of leading evolutionists and a detailed examination of what relevant concepts—such as homology, Simpson’s QUANTUM LEAP, RNA, etc. . . .”— book review by Margaret Mead of ‘Evolution and Christian Thought Today’ (1959) by Mixter, in ‘American Anthropologist,’ Vol. 63, No. 2, Part 1, April, page 395>

<1970 “The ability of marine technology to take ‘QUANTUM’ LEAPS in innovation means that a laissez-faire approach to the ocean mineral resources can no longer be tolerated.”—‘New Scientist,’ 3 December, page 372/1>

<1973 “Hovercraft, like many inventions of modern technology, are supposed to progress in QUANTUM LEAPS.”—‘Daily Telegraph’ (Colour Supplement), 2 November, page 27/2>

<1977 “The imperial Presidency did not begin with Richard Nixon although under him abuses of the office took a QUANTUM LEAP.”—‘New Yorker,’ 13 June, page 108/2>

<1983 “The geneticist Richard Goldschmidt proposed that a sudden jump of this kind should be called a ‘saltation’ since it clearly involves much more than a mutation. George G. Simpson felt that this term came too near to the supernatural concept of creation. So he proposed instead the use of the term a QUANTUM LEAP, borrowing from physics which thus gave it a more respectable parentage!”—‘Two Men Called Adam,” Chapter 3, by Arthur Custance>
(Barnhart Concise Dictionary of Etymology, Oxford English Dictionary)

Ken G – July 24, 2005

quantum leap

Posted: Mon Jul 25, 2005 4:45 pm
by dalehileman
Ken underscores a most interesting point. Presumably if it happened at just the right time and place, a quantum jump, however small, could reverse the course of history

Which brings up determinism. If physics and not Godly intervention determines the sequence of events; then if the clock could somehow be reset to the moment of the Big Bang, everything thereafter would duplicate what has happened in the meantime; and so the subsequent (or second) "present" would be just as it is now, nothing changed.

Therefore to escape the dreary conclusion that free will is impossible, and barring other kinds of miracle, either the quantum change is causeless or God --in Her infinite wisdom--now and again tweaks the atom in order to introduce an element of unpredictability

However, some will argue, that wouldn't resolve the issue because still leaves us without free will

quantum leap

Posted: Mon Jul 25, 2005 9:02 pm
by spiritus
The previous posting is in contextual accordance with Everett's Relative-State-Interpretation or 'Many Worlds' and "minds" interpretation, as opposed to the 'Copenhagen interpretation'.

quantum leap

Posted: Mon Jul 25, 2005 11:26 pm
by haro
Thanks Ken. I often wondered when and how the term left its physical background, but I never brought myself to do some research of my own. It was just one of those phenomena I noticed with a chuckle, occasionally made fun of it but never bothered much about.

quantum leap

Posted: Tue Jul 26, 2005 12:08 am
by Ken Greenwald
Che, Tossing around buzzwords such as “quantum entanglement,” “Everett's Relative-State-Interpretation or 'Many Worlds' and ‘minds’ interpretation, as opposed to the 'Copenhagen interpretation,'” which most of our readers know nothing about (and that’s not nice), doesn’t make the obvious lack of knowledge of the basics that you’ve displayed any less apparent, and, in fact, gives the impression of a puffed up pipsqueak making a great effort to sound impressive. I recommend you put a sock in it!

Ken G – July 25, 2005

quantum leap

Posted: Tue Jul 26, 2005 2:08 am
by Ken Greenwald
Dale, That is a very interesting point. However, I have a problem with it:
<"Which brings up determinism. If physics and not Godly intervention determines the sequence of events; then if the clock could somehow be reset to the moment of the Big Bang, everything thereafter would duplicate what has happened in the meantime; and so the subsequent (or second) "present" would be just as it is now, nothing changed.”>
I’m no expert on determinism, etc., but here’s a very simplistic way of looking at this without getting into some very deep philosophical questions. Offhand, it would seem that if physics determines the sequence of events, then everything would come out somewhat differently each time you restarted. For, example, if quantum mechanics is at play, exactly what happens in various atomic and nuclear events is probabilistic. So that, for example, a high energy particle released in a reaction could have gone one way or another, and if the reaction were replayed it most likely would not go exactly the same way – that’s the difference between the determinism of Newton’s mechanics (tell me the initial conditions and the path is set) versus quantum mechanics which says that the outcome is probabilistic. So if that high energy particle went one way, it might have passed trough some DNA in a piece of primordial slime of early earth and caused a mutation that sent that particular form of life on a particular path. However, according to quantum mechanics, that particular path of the high energy particle was just one of many possibilities and, if the event were repeated, the particle could very well have not interacted with that particular piece of slime and might have missed the earth entirely. Multiply that by the number of quantum events that have occurred since the big bang and I think that the chances of things coming out exactly the same are as close to zero as you care to get. However, broadly speaking, it might be true that the overall structure of the universe (distribution of galaxies etc.) might be similar if the initial conditions at the time of the big bang were exactly the same, but I don’t think any one is saying that the details would be. Again, I am not speaking from any deep knowledge or analysis of this subject, but just from what appears, on the surface at least, to be the case from the meanings of the words ‘physics’ and ‘probabilistic.’

Ken – July 25, 2005

quantum leap

Posted: Tue Jul 26, 2005 4:59 pm
by Ken Greenwald
Che, You proceed to make my point for me and I do enjoy puncturing a stuffed shirt now and then as we (but especially yourself) continue to be duly impressed by the use of big words and abstruse ideas. And now we can add to the list: RST [[Reciprocal System Theory - a crock of pseudoscientific hogwash that is a laughingstock in the world of physics]], QUALQuantum Anthopological Linguistics [[wow!]], Quantum Philosophy, Quantum Theory, String Theory, Quantum Consciousness and Cognition [[Gee!]]. Keep up the good work. (<:)

Ken G – July 26, 2005

quantum leap

Posted: Tue Jul 26, 2005 7:57 pm
by Shelley
I'm a complete novice on this topic but I love it. Applying the uncertainty principle to dalehileman's question re: would everything be deja vu all over again if the clock were reset back to 00:00 (big bang), I would venture that events would likely happen differently because they would be effected by the act of observation (after all, who'd be resetting the clock? -- or would it reset itself?). The very act of resetting would probably effect the big bang itself, and all that cosmic matter would go flying off in completely new directions. Suppose it was possible to have the second big bang occur in exactly the same manner as it did the first time: even if things looked like they were happening absolutely identically the second time around, we'd never really know for sure, due to the same principle.
There's no need to bother correcting me on my faulty reasoning, or misinterpretation of facts, unless you detect in the above a severe flaw in my understanding of Heisenberg's Uncertainty Principle (like having it backwards, for example).

quantum leap

Posted: Tue Jul 26, 2005 9:39 pm
by Phil White
Heisenberg's uncertainty principle:
After three pints of Heisenberg, you're pretty uncertain.

quantum leap

Posted: Tue Jul 26, 2005 11:39 pm
by Shelley
I'll drink to that!
(Did you say that 'cause I got the name wrong? It would be just like me to do that -- after going off about cosmic matter and stuff . . .)
I have a headache.

quantum leap

Posted: Wed Jul 27, 2005 4:24 am
by Ken Greenwald
Phil, And I was uncertain even before I started!

Shelley, You got the name right and it is the Heisenberg uncertainty principle, which states that it is impossible to know at the same time the precise position and momentum of an object, or alternatively the precise energy and the time the object has that energy. However, the probabilistic nature of the position of a particle in space and time is described by the quantum mechanical wave equation (Schrödinger’s equation) and the Heisenberg uncertainty principle isn’t really required to find the probability of a particle’s location. However, the Uncertainty Principle does quantify (in a equation) the limitations on our knowledge of the particle’s position when making a measurement, which does reinforces the idea that we may, at best, only have an imprecise knowledge of a particle’s path.

As far as rerunning the big bang, it’s not entirely clear to me how Heisenberg’s uncertainty principle applies to Dale’s question. However, I did give my thoughts on the rerun in my above response to Dale (“Dale, That is a very interesting point.”). But I really am not expert enough on these types of questions to give an authoritative answer. Quantum mechanics, etc. is very weird and the intricacies and implications are many. I think that the great 20th century physicist Richard Feynman (at least it has been widely attributed to him for years, although I never did see a direct quote) stated it best when he purportedly said:

“Anyone who claims they understand quantum mechanics is lying.”

And I think he would also apply that, if he were alive today, to some of the newer theories. I just read, for example, in last week’s Science News (Vol. 168, No. 3, page 38, July 16, 2005) an article with the title:
"Realistic Time Machine? New design could forgo exotic ingredient.”
If folks are seriously talking about time machines, etc., that’s one step beyond what I can fathom (raises some very sticky questions about what would happen if one killed one’s grandfather if one could go back in time – although some physicists counter that life would go on without you in one of an infinite number of parallel universes but you would continue to exist in ours).

If you’re into strange, here is one of the stranger consequences of quantum mechanics (QM) that was held up as an example of why it must be wrong, until an experiment performed in Geneva, Switzerland, in 1997 first confirmed its truth. And what follows is a very sketchy picture of what this is all about:

In 1935 a paper written by Einstein, Podolsky, and Rosen ("Can Quantum Mechanical Description of Physical Reality Be Considered Complete?”), later to be known as the EPR paradox, was introduced. It said, in effect, that if QM were true and consistent, it would also be true that the result of a measurement of two entangled (e.g. born at the same time and place and thus related in some way) particles in one part of a quantum system would instantaneously (that’s in zero time!) affect the result of an measurement of the other entangled particle in another part of the system. For example, consider two spinning particles, which upon creation shoot off in opposite directions, say one spinning CCW (+1 ) and the other CW (–1) for a sum of 1 – 1 = 0. Flip the one particle when it is 1000 miles away from the creation point and instantaneously the other one that went 1000 miles in the other direction will ‘know’ this and flip to maintain their entangled sum of ‘0.’ This process of instantaneous reaction at a distance due to quantum entanglement is know as ‘nonlocality’ (an effect caused by something that is not necessarily nearby or local) regardless of the distance between them – say, half way across the universe, for instance. For some 60 years this was held up as a flaw in QM that seemed to show that it was inconsistent and not a complete theory, for if it were true, then information was being propagated at faster than the speed of light, which would violate Einstein’s theory of relativity. However, as it turned out, the recent experiments showed that things did happen instantaneously as predicted, but theory explained, that, technically, ‘information’ was not being transmitted and thus relativity was not being violated. I’ve read the original paper and I’ve poured over the various explanations and, to be honest, I still don’t understand it! But those that do, claim it is a done deal.

And if you’re into goofy, how about this. One of the cornerstones of physics is that ‘information’ cannot be destroyed (law of conservation of information) – I lost my pocket daytimer in Chicago last month at my son’s graduation ceremony. It’s lost to me, but theoretically it is recoverable! But back in 1997 University of Cambridge cosmologist Stephen J. Hawking and and Kip Thorne of the California Institute of Technology in Pasadena bet another Caltech theorist, John Preskill, that if an encyclopedia got sucked into a black hole, the information in those volumes would vanish forever. Others had reasoned that if information got sucked into a black hole it would not get destroyed, although it would be inaccessible, since nothing gets out of a black hole and thus the information in the universe would be conserved. But Hawking and Thorne reasoned that since black holes are not really completely black and emit small amounts of radiation – Hawking had shown (with the aid of the Heisenberg Uncertainty Principle) back into 1975 that black holes actually ‘evaporate’ (now called Hawking radiation) although very slowly. A fair size black hole might take 10^66 years to disappear, which is a very long time, but not an eternity. So, Hawking deduced that information would be irretrievably dispersed and disappear with the decay of the black hole, which was a bit upsetting to most physicists, including Hawking himself, since it violated the law of conservation of information and the universe was losing information – definitely not good!

Recently, however, after nearly 30 years, Hawking has reversed his opinion and claims he has figured out that information is actually being conserved. Even black holes can't destroy information, he announced in July of 2004 at the International Conference on General Relativity and Gravitation in Dublin as he humbly conceded his 1997 bet by presenting Preskill with a baseball encyclopedia. Although Preskill graciously accepted the book, he said that he wouldn't consider the bet decided until Hawking fully explained the physics behind his reversal. Last I heard Hawking was preparing a paper on the subject for publication, but it’s not out yet. Stay tuned for his vital proof, which could have serious implications for the price of sliced bread. (&lt)

Ken G – July 26, 2005

quantum leap

Posted: Wed Jul 27, 2005 5:46 am
by Erik_Kowal
Gertrude Stein laid out her own uncertainty principle:

"The minute you or anybody else knows what you are you are not it, you are what you or anybody else knows you are and as everything in living is made up of finding out what you are it is extraordinarily difficult really not to know what you are and yet to be that thing."

Finally, it should be noted that this remark is merely attributed to Stein because it is unclear who is supposed to have observed her saying it, or in what context; in other words, who knows if she actually said it?

I hope that says it all; otherwise, I may or may not have to revise my assessment.

quantum leap

Posted: Wed Jul 27, 2005 8:08 am
by Phil White
Personally, I've always found it rather easier to grasp at least an inkling of what Heisenberg was rattling on about than to even begin to grasp what Gertrude Stein was writing.

To apply Heisenberg's uncertainty principle to Gertrude Stein:
Of Gertrude Stein, it is (was) only possible to know that she was on another planet or how fast she was approaching being on another planet, but never both at the same time.

But I do like the quote. Perhaps I shall venture to dip my toe into Stein's writing again.

quantum leap

Posted: Wed Jul 27, 2005 1:17 pm
by Shelley
I'll dip into that large stein of heisenberg, now, please.