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title: 'Wave or corpuscules? or both ...' |
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media_order: 'corpuscule-trajectory-tennis-ball.jpg,refraction-cuillere.jpg,sky-light-rays-827.jpg,wave-corpuscular-nature-of-light-experiment1.gif,waves-interferences-surface-water-827-496.jpg,reflexion-statuette.jpg' |
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--- |
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### How do we understand our physical world ? |
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* We interpret the world with two intuitive concepts that are in our mind mutually exclusive : the concept of corpuscule and the concept of wave |
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##### Localized corpuscules with trajectories |
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In our mind, a **corpuscule** is *localized in space*, and **At each instant** can be characterized by : |
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* a *position in space* |
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* a *speed* |
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* an *acceleration* |
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It carries : |
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* *matter* |
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* *energy* |
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* *momentum* |
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Between two instants, its movement describes a *trajectory* : continuous set of positions followed by the corpuscule between these two instants. |
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The **behavior of a corpuscule** *at human scale*, and **their interactions with each other**, is well described and predicted by *classical mechanics*. |
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* **classical mechanics** = **Newton's mechanics** = **point mechanics** |
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##### Waves that interfer to each other |
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In our mind, a **wave** is *not localized in space*, and **in the whole time** can be characterized by : |
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* a *frequency* |
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* a *velocity* |
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* frequency + velocity $\Longrightarrow$ a *wavelength* |
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* an *amplitude* |
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* a *polarization* (depending of wave type) |
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A wave |
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* *does not carry matter* |
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* *carries energy* |
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**Several waves** interfer with each other, giving rise to *interferences* |
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A wave **passing through a small aperture** (of size of the order or small than wavelength) is *diffracted* |
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### How light behaves ? |
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A modern Youngs'type experiment : |
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behavior of light passing through two slits and |
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The light emerging from a double slit, whose the width (of each slot) and the spacing (between the two slots) are sufficiently small, |
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### What optical phenomena do we observe in everyday life ? |
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* The **light** describes in *straight lines in air*.<br> |
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$\Longrightarrow$ concept of *light ray* |
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##### Refraction phenomenon |
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* The light seems to *change direction from water to air*.<br> |
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* can be d |
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##### Reflection phenomenon |
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