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"all analogies are false and therefore bad" I disagree with this statement. If you try to learn everything from first principles, you'll never get anywhere.

"all analogies are false and therefore bad" I disagree with this statement. If you try to learn everything from first principles, you'll never get anywhere. Students need analogies to understand the big picture while learning the details. "That is not just a good analogy, but summarizes our best understanding of both light and quantum physics" And the Lesbeque integral is a more rigourously defined operator that the Riemann integral, but would you use it to introduce calculus to first year students? Of course not - you teach the basics, and in grad school, you let the students that need to worry about the more complicated stuff take Real Analysis. There are certainly connections between interferometry and quantum physics. However, I don't see how the author's explanation of the subject is enhanced by using quantum physics. For the purpose of this article, classical physics explains the phenomenology just fine. As I said in another comment below, and wglb said above, appealing to quantum physics when it is entirely unnecessary is a bad smell, and is usually nothing more than a distraction to make the author sound more sophisticated.

ssivark 12y ago
The Lebesgue integral can be explained as intuitively as the Riemann integral (https://en.wikipedia.org/wiki/Lebesgue_integration#mediaviewer/File:RandLintegrals.png https://en.wikipedia.org/wiki/Lebesgue_integration#mediaview...). One can certainly have the intuition for both without too much knowledge of real analysis. And in general, I believe that analogies are very useful. The author explains in the article how to understand the behaviour of light. It turns out quantum particles behave in exactly the same way. Feynman (building on Dirac's observations) built up the theory for quantum particles. With regards to light, this understanding comes from a couple of centuries ago (Ref: [Huygens principle](https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_princi...) and [relations to quantum mechanics](https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle#Huygens.27_principle_and_quantum_electrodynamics) https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_princi...)
- abstrakraft 12y ago
  "The author explains in the article how to understand the behaviour of light." That isn't the argument. What I'm arguing is the (lack of) utility of the explanation. In what way does it enhance, support, or in any way contribute to the article? His argument is essentially: A. We think of light as traveling in straight lines. B. But because quantum physics, they don't! They travel along infinitely many paths. C. But all of these paths cancel out except the straight line path. D. And that's how beamforming works. Except it's beam-un-forming. So he brings up a quantum phenomenon to complicate the scenario, then immediately reduces it back to the original scenario, without ever explaining how that original scenario works (i.e. how waves add together to create constructive and destructive interference: note that the words "wave" and "phase" never occur in same paragraph), then claims that this is somehow elucidating. So what's the benefit?
  - judk 12y ago
    As stated in the article, the point is to give an intuition for how energy appears to "move" from troughs to peaks: by going everywhere. This coincides with the Pilot Wave model, where particles travel along paths modeled by the peaks of mathematical waves.

ssivark 12y ago

The Lebesgue integral can be explained as intuitively as the Riemann integral (https://en.wikipedia.org/wiki/Lebesgue_integration#mediaviewer/File:RandLintegrals.png https://en.wikipedia.org/wiki/Lebesgue_integration#mediaview...). One can certainly have the intuition for both without too much knowledge of real analysis. And in general, I believe that analogies are very useful. The author explains in the article how to understand the behaviour of light. It turns out quantum particles behave in exactly the same way. Feynman (building on Dirac's observations) built up the theory for quantum particles. With regards to light, this understanding comes from a couple of centuries ago (Ref: [Huygens principle](https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_princi...) and [relations to quantum mechanics](https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_principle#Huygens.27_principle_and_quantum_electrodynamics) https://en.wikipedia.org/wiki/Huygens%E2%80%93Fresnel_princi...)

abstrakraft 12y ago
"The author explains in the article how to understand the behaviour of light." That isn't the argument. What I'm arguing is the (lack of) utility of the explanation. In what way does it enhance, support, or in any way contribute to the article? His argument is essentially: A. We think of light as traveling in straight lines. B. But because quantum physics, they don't! They travel along infinitely many paths. C. But all of these paths cancel out except the straight line path. D. And that's how beamforming works. Except it's beam-un-forming. So he brings up a quantum phenomenon to complicate the scenario, then immediately reduces it back to the original scenario, without ever explaining how that original scenario works (i.e. how waves add together to create constructive and destructive interference: note that the words "wave" and "phase" never occur in same paragraph), then claims that this is somehow elucidating. So what's the benefit?
- judk 12y ago
  As stated in the article, the point is to give an intuition for how energy appears to "move" from troughs to peaks: by going everywhere. This coincides with the Pilot Wave model, where particles travel along paths modeled by the peaks of mathematical waves.