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Foucault Hoodie
THE FLOOR TURNS UNDER ME | Pixelated Physics
Can a pendulum prove the Earth spins? In 1851 Léon Foucault hung one in Paris and watched its swing plane slowly turn. The rate is Ω = ω⊕ sin φ at latitude φ, so a full turn takes one sidereal day at the poles, about 31.8 hours at Paris, and never happens at the equator. Black pixel-art hoodie; equation, symbols and sources in the physics panel below.
Size guide S–5XL · inches
Flat $6 shipping worldwideMade to order, ships in 2–5 business days
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Details
Size & fitS–5XL
Unisex Heavy Blend hoodie (Gildan 18500), classic fit.
| Size | Width | Length | Sleeve |
|---|---|---|---|
| S | 20 | 27 | 33.5 |
| M | 22 | 28 | 34.5 |
| L | 24 | 29 | 35.5 |
| XL | 26 | 30 | 36.5 |
| 2XL | 28 | 31 | 37.5 |
| 3XL | 30 | 32 | 38.5 |
| 4XL | 32 | 33 | 39.5 |
| 5XL | 34 | 34 | 40.5 |
Measurements in inches. Width and length ±1 in, sleeve (from center back) ±0.75 in.
ShippingFree US
Flat $6 shipping on every order, worldwide.
Returns & replacements21 days
Every item is printed to order, so we can’t accept returns or exchanges for change of mind, or if you ordered the wrong size or colour.
Print defect, misprint, damage or the wrong item? We’ll send a free replacement, or a refund if you prefer. Report it within 21 days of delivery with a photo; no need to send it back.
The physics
Equations
| Symbol | Meaning | Unit |
|---|---|---|
| \(\Omega\) | angular rate of the swing-plane precession | \(\mathrm{rad/s}\) |
| \(\omega_\oplus\) | Earth sidereal rotation rate (7.292115\times10^{-5} rad/s) | \(\mathrm{rad/s}\) |
| \(\phi\) | geographic latitude | \(\mathrm{rad}\) |
| \(\dot\theta\) | rate of change of the swing azimuth | \(\mathrm{rad/s}\) |
| \(T\) | period for a full 360° precession of the plane | \(\mathrm{s}\) |
Sources
- Foucault (1851) Démonstration physique du mouvement de rotation de la Terre, Comptes rendus
- Halliday, Resnick & Walker, Fundamentals of Physics, Ch. on non-inertial frames / Foucault pendulum
- Wikipedia, Foucault pendulum (opens in a new tab)
Field notes
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