6 ms·

"To break the minute barrier [they] fired a control laser at an opaque crystal, sending its atoms into a quantum superposition of two states. This made it trans

by sramsay 13y ago

"To break the minute barrier [they] fired a control laser at an opaque crystal, sending its atoms into a quantum superposition of two states. This made it transparent to a narrow range of frequencies. Heinze's team then halted a second beam that entered the crystal by switching off the first laser and hence the transparency." Thus continuing my inability to understand what the fuck anyone is talking about whenever the word "quantum" is used in a sentence. I mean, seriously. This has to be the one area of general reader science journalism in which the journalists -- having about as much as idea as I do about what the physicists are talking about -- just copy down whatever the guys in the lab coats are saying and print it. I work in research computing. When I start talking to someone from our communications department and use a word like "interoperability," they say, "Whoa, slow down. You have to spell that out for our readers." But "quantum superposition?" Oh, what the hell. I understand that is this very, very complicated stuff, and that they can't explain the whole thing from top to bottom every time they mention quantum mechanics. But pithy little paragraphs like this explain absolutely nothing.

jcbrand 13y ago
There is a Wikipedia article about "Quantum superposition". https://en.wikipedia.org/wiki/Quantum_superposition https://en.wikipedia.org/wiki/Quantum_superposition In quantum states, you cannot know the actual state something is in unless you measure it. Beforehand, you just have different probabilities of where it might be. A quantum superposition of two states means that there are two states the atoms can be in, with specific probabilities assigned to each state.
- sramsay 13y ago
  Right, and issue three of this article's "multiple issues" is "This article may be too technical for most readers to understand. (April 2011)"
amirmc 13y ago
My layman's reading of this. We used a crystal that is normally opaque (not see-through) and fired laser beams at it because, well... it seemed like fun! Apparently the laser beam affected the crystal and made it see-through but only for a narrow range of light frequencies (e.g. think of a filter that only allows one colour of light through). Then we thought Hey, we know how to make this here crystal see-through for a particular wavelength of light (think 'colour' if wavelength doesn't work for you). What if we (1) made it see-through with the laser, (2) shone some of that colour light in and then (3) turned off the laser so that it's no longer see-through. I wonder what happens? <time passes> zOMG! We trapped light! In other words, I do think it's possible to get the message across without needing to refer to 'quantum' anything. However, this article is from NewScientist and the intended audience is likely to be vaguely familiar with concepts of superposition via stories of Schrödinger's cat [1] [1] http://en.wikipedia.org/wiki/Schrödinger's_cat http://en.wikipedia.org/wiki/Schrödinger's_cat
- alanctgardner2 13y ago
  Your understanding is actually pretty good (lines up with mine, at least), and I liked your explanation except for the needlessly conversational tone. Basically by only cutting things out: > We used a crystal that is normally opaque (not see-through) and fired laser beams at it [which] made it see-through but only for a narrow range of light frequencies (e.g. a filter that only allows one colour of light through). [Then] we made [the crystal] see-through with the laser, shone some of that colour light in and turned off the laser so that it's no longer see-through. We trapped light!
  - amirmc 13y ago
    > "... except for the needlessly conversational tone." Yes, I agree it's not necessary to get the basic information across but it was definitely a lot more fun to write that way! If I were really writing piece for an article or blog post I'd take a lot more care and probably consider using better analogies.
    - TeMPOraL 13y ago
      > Yes, I agree it's not necessary to get the basic information across but it was definitely a lot more fun to write that way! I agree; for me, "conversational tone" is usually much more fun to write, and much more fun to read. I find it a sign of a good understanding of the topic if one can phrase his explenation in a conversational tone. You have to know your stuff well to be able to correctly express complicated ideas in simple terms.
      - alanctgardner2 13y ago
        'Tone' may have been the wrong word. Obviously he understands, he did explain it well. I was just trying to point out that he added a bunch of noise under the guise of being conversational. Cutting out the noise makes it concise will remaining accessible - I don't think my edits actually changed the tone.
        13y ago
Jun8 13y ago
I think a good way to think about sentences like that is that the word quantum is short for "belonging to quantum mechanics", like how "classical gravitation" doesn't mean that there's anything classic about gravitation. The quantum quantifier is there to differentiate the superposition they mention from "classical" wave superposition. It's very complicated stuff but not "very, very complicated" stuff, you can read Feynman's QED book (http://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691083886 http://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/069..., <$9 used with shipping) and obtain a pretty good working knowledge of things.
Arjuna 13y ago
"Thus continuing my inability to understand [...]" You will enjoy this beautiful lecture given by Dr. Feynman entitled, "Probability and Uncertainty - The Quantum Mechanical View of Nature." [1] In this lecture, he describes the double-slit experiment, which is tied to the topic of quantum superposition. This particular section blows me away every time: "Here are the circumstances: source, strong light source; tell me, behind which hole will I see the electron? You say, 'Well, the reason you can't tell through which hole you're going to see the electron is, it's determined by some very complicated things back here: if I knew enough about that electron - it has internal wheels, internal gears, and so forth - and that this is what determines through which hole it goes. It's 50/50 probability because, like a die, it's set sort of at random - and if I were to have studied it carefully enough, your physics is incomplete: if you get a complete enough physics, then you'll be able to predict through which hole it goes.' That's the 'hidden variable' theory, so called. Well, that's not possible. It is not due to a lack of detailed knowledge that we cannot make a prediction, because I said that if I didn't turn on the light, I should get this interference pattern. If I have a circumstance in which I get that interference pattern, then it is impossible to analyze it in terms of saying, it goes through here or here, because that curve is so simple, mathematically - a different thing than the contribution of this and this as probabilities. So if it were possible for you to have determined through which hole it was going to go if I had the light on, the fact that I had the light on hasn't got anything to do with it! Whatever gears there are back here that you observe, which permitted you to tell me whether is was going to go through 1 or 2, you could have observed if I had the light off. And therefore you could have told me with the light off which hole - each time an electron goes - which hole it's going to go through. But if you can do this, then that curve would have to be represented as the sum of those that go through there and those that go through there - and it ain't. Therefore, it's impossible to have information ahead of time as to which hole it's going to go through when the light is out - or when the light is on, or out - in a circumstance where the experiment is set up that can produce this interference pattern. It is not a lack of unknown gears - a lack of internal complications - that makes nature have probability in it; it seems to be in some sense intrinsic. Someone has said it this way: 'nature herself doesn't know which way the electron is going to go.' A philosopher once said (a pompous one): 'it is necessary for the very existence of science that the same conditions always produce the same result.' Well, they don't: if you set up electrons in any way - I mean, you set up the circumstance here, in the same conditions every time, and you cannot predict behind which hole you'll see the electron. They don't - and yet the science goes on in spite of him." [1] https://www.youtube.com/watch?v=OCFX_NHBefI https://www.youtube.com/watch?v=OCFX_NHBefI
kineticfocus 13y ago
I think the article struck the right balance... Stories like these first appear in the more serious media circles first, and then filter out into the mainstream. A long time ago I remember reading scientific americans that tended to be more technical then whats out in the mainstream nowadays. There's room for news sources that fit between the raw whitepapers and the mainstream.
atondwal 13y ago
APS typically features important results with articles that are not only understandably by the quantitative laymen, but also do a good job of communicated content. (They're supposed to be the least common denominator for interdisciplinary physicists.) Here's the article for this paper: http://physics.aps.org/articles/v6/80 http://physics.aps.org/articles/v6/80
ohwp 13y ago
http://xkcd.com/1240/ http://xkcd.com/1240/
mathattack 13y ago
I almost feel like this is the one field where if you know enough to explain it, you are working in the field, not in the business of explaining it. If that makes sense...
thangalin 13y ago
http://davidjarvis.ca/entanglement/ http://davidjarvis.ca/entanglement/ I wrote a few pages explaining quantum entanglement in rudimentary terms... and without relying on math, which you'll find too much of on the Wikipedia pages.

by sramsay 13y ago

jcbrand 13y ago

There is a Wikipedia article about "Quantum superposition". https://en.wikipedia.org/wiki/Quantum_superposition https://en.wikipedia.org/wiki/Quantum_superposition In quantum states, you cannot know the actual state something is in unless you measure it. Beforehand, you just have different probabilities of where it might be. A quantum superposition of two states means that there are two states the atoms can be in, with specific probabilities assigned to each state.

sramsay 13y ago
Right, and issue three of this article's "multiple issues" is "This article may be too technical for most readers to understand. (April 2011)"

amirmc 13y ago

My layman's reading of this. We used a crystal that is normally opaque (not see-through) and fired laser beams at it because, well... it seemed like fun! Apparently the laser beam affected the crystal and made it see-through but only for a narrow range of light frequencies (e.g. think of a filter that only allows one colour of light through). Then we thought Hey, we know how to make this here crystal see-through for a particular wavelength of light (think 'colour' if wavelength doesn't work for you). What if we (1) made it see-through with the laser, (2) shone some of that colour light in and then (3) turned off the laser so that it's no longer see-through. I wonder what happens? <time passes> zOMG! We trapped light! In other words, I do think it's possible to get the message across without needing to refer to 'quantum' anything. However, this article is from NewScientist and the intended audience is likely to be vaguely familiar with concepts of superposition via stories of Schrödinger's cat [1] [1] http://en.wikipedia.org/wiki/Schrödinger's_cat http://en.wikipedia.org/wiki/Schrödinger's_cat

alanctgardner2 13y ago
Your understanding is actually pretty good (lines up with mine, at least), and I liked your explanation except for the needlessly conversational tone. Basically by only cutting things out: > We used a crystal that is normally opaque (not see-through) and fired laser beams at it [which] made it see-through but only for a narrow range of light frequencies (e.g. a filter that only allows one colour of light through). [Then] we made [the crystal] see-through with the laser, shone some of that colour light in and turned off the laser so that it's no longer see-through. We trapped light!
- amirmc 13y ago
  > "... except for the needlessly conversational tone." Yes, I agree it's not necessary to get the basic information across but it was definitely a lot more fun to write that way! If I were really writing piece for an article or blog post I'd take a lot more care and probably consider using better analogies.
  - TeMPOraL 13y ago
    > Yes, I agree it's not necessary to get the basic information across but it was definitely a lot more fun to write that way! I agree; for me, "conversational tone" is usually much more fun to write, and much more fun to read. I find it a sign of a good understanding of the topic if one can phrase his explenation in a conversational tone. You have to know your stuff well to be able to correctly express complicated ideas in simple terms.
    - alanctgardner2 13y ago
      'Tone' may have been the wrong word. Obviously he understands, he did explain it well. I was just trying to point out that he added a bunch of noise under the guise of being conversational. Cutting out the noise makes it concise will remaining accessible - I don't think my edits actually changed the tone.
      - 13y ago

Jun8 13y ago

I think a good way to think about sentences like that is that the word quantum is short for "belonging to quantum mechanics", like how "classical gravitation" doesn't mean that there's anything classic about gravitation. The quantum quantifier is there to differentiate the superposition they mention from "classical" wave superposition. It's very complicated stuff but not "very, very complicated" stuff, you can read Feynman's QED book (http://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/0691083886 http://www.amazon.com/QED-Strange-Theory-Light-Matter/dp/069..., <$9 used with shipping) and obtain a pretty good working knowledge of things.

Arjuna 13y ago

"Thus continuing my inability to understand [...]" You will enjoy this beautiful lecture given by Dr. Feynman entitled, "Probability and Uncertainty - The Quantum Mechanical View of Nature." [1] In this lecture, he describes the double-slit experiment, which is tied to the topic of quantum superposition. This particular section blows me away every time: "Here are the circumstances: source, strong light source; tell me, behind which hole will I see the electron? You say, 'Well, the reason you can't tell through which hole you're going to see the electron is, it's determined by some very complicated things back here: if I knew enough about that electron - it has internal wheels, internal gears, and so forth - and that this is what determines through which hole it goes. It's 50/50 probability because, like a die, it's set sort of at random - and if I were to have studied it carefully enough, your physics is incomplete: if you get a complete enough physics, then you'll be able to predict through which hole it goes.' That's the 'hidden variable' theory, so called. Well, that's not possible. It is not due to a lack of detailed knowledge that we cannot make a prediction, because I said that if I didn't turn on the light, I should get this interference pattern. If I have a circumstance in which I get that interference pattern, then it is impossible to analyze it in terms of saying, it goes through here or here, because that curve is so simple, mathematically - a different thing than the contribution of this and this as probabilities. So if it were possible for you to have determined through which hole it was going to go if I had the light on, the fact that I had the light on hasn't got anything to do with it! Whatever gears there are back here that you observe, which permitted you to tell me whether is was going to go through 1 or 2, you could have observed if I had the light off. And therefore you could have told me with the light off which hole - each time an electron goes - which hole it's going to go through. But if you can do this, then that curve would have to be represented as the sum of those that go through there and those that go through there - and it ain't. Therefore, it's impossible to have information ahead of time as to which hole it's going to go through when the light is out - or when the light is on, or out - in a circumstance where the experiment is set up that can produce this interference pattern. It is not a lack of unknown gears - a lack of internal complications - that makes nature have probability in it; it seems to be in some sense intrinsic. Someone has said it this way: 'nature herself doesn't know which way the electron is going to go.' A philosopher once said (a pompous one): 'it is necessary for the very existence of science that the same conditions always produce the same result.' Well, they don't: if you set up electrons in any way - I mean, you set up the circumstance here, in the same conditions every time, and you cannot predict behind which hole you'll see the electron. They don't - and yet the science goes on in spite of him." [1] https://www.youtube.com/watch?v=OCFX_NHBefI https://www.youtube.com/watch?v=OCFX_NHBefI

kineticfocus 13y ago

I think the article struck the right balance... Stories like these first appear in the more serious media circles first, and then filter out into the mainstream. A long time ago I remember reading scientific americans that tended to be more technical then whats out in the mainstream nowadays. There's room for news sources that fit between the raw whitepapers and the mainstream.

atondwal 13y ago

APS typically features important results with articles that are not only understandably by the quantitative laymen, but also do a good job of communicated content. (They're supposed to be the least common denominator for interdisciplinary physicists.) Here's the article for this paper: http://physics.aps.org/articles/v6/80 http://physics.aps.org/articles/v6/80

ohwp 13y ago

http://xkcd.com/1240/ http://xkcd.com/1240/

mathattack 13y ago

I almost feel like this is the one field where if you know enough to explain it, you are working in the field, not in the business of explaining it. If that makes sense...

thangalin 13y ago

http://davidjarvis.ca/entanglement/ http://davidjarvis.ca/entanglement/ I wrote a few pages explaining quantum entanglement in rudimentary terms... and without relying on math, which you'll find too much of on the Wikipedia pages.