essential
likely
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probably not
Front (prompt)
Wien's Displacement Law — formula and the two peak wavelengths to know?
Plain English (default view) — short, conversational, lightly seasoned with science
**Hot things glow short, cool things glow long.** That's the whole law in plain terms. - The **Sun** is super hot, so it glows in **visible light** (we can see it). - The **Earth** is cool, so it glows in **thermal infrared** (we can't see it, but our sensors can). That's exactly why we use VIS/NIR sensors to capture reflected sunlight, and **thermal infrared sensors** to capture Earth's own heat — at night, in the dark, all the time.
🔬 Scientific / formula (revealed on click) — markdown + $$…$$ ok
`λ_max = 2897.8 / T` (µm, T in K) - **Sun (~6000 K):** λ_max ≈ **0.483 µm** (visible) - **Earth (~300 K):** λ_max ≈ **9.66 µm** (thermal IR) Hotter → shorter peak wavelength.
💡 Mnemonic / memory aid (shown on hover)
Hot = short, cool = long. Sun hot → 0.48 µm (visible). Earth cool → 9.66 µm (thermal IR). That's why we use VIS/NIR for reflected solar and thermal IR for emitted Earth.
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