• Nutreon – Brazil Nut Effect physics T-shirt
  • Nutreon – Brazil Nut Effect physics T-shirt
  • Nutreon – Brazil Nut Effect physics T-shirt
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NutreonBrazil Nut Effect (Granular Convection)

Nutreon – Brazil Nut Effect (Granular Convection) Physics T-Shirt

$29.99 USD
$29.99 USD
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Shipping calculated at checkout. Free US shipping · $10 flat shipping outside the US.
Color
White · Black
Size
S–5XL
Made
To order · shipping times

Why do the Brazil nuts end up on top? Shake a mix of large and small grains and the large ones tend to rise. Small grains fill gaps beneath big ones, and convection rolls can carry big pieces upward. Which mechanism dominates depends on the shaking and the grains, and it is still debated. Nutreon rises anyway. Pixel-art unisex tee; equation, symbols and sources in the physics panel below.

Color
Size

Size guideS–5XL · inches

Details

Size & fitS–5XL

Unisex heavy cotton (Gildan 5000), classic fit.

SizeWidthLengthSleeve
S182815.1
M202916.5
L223018
XL243119.5
2XL263221
3XL283322.4
4XL303423.7
5XL323525

Measurements in inches, ±1.5 in tolerance.

ShippingFree US

Free US shipping · $10 flat shipping outside the US. Printed to order for you.

Delivery times & where we ship

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.

Full refund & replacement policy

The physics

Shake a jar of mixed nuts and the big Brazil nuts end up on top, even though they are the heaviest.

Once the shaking acceleration beats gravity, the grains start to move. Small grains fall into gaps opening beneath large ones, and the grains circulate in slow convection rolls: up the middle, down the walls in a thin layer too narrow for the big nuts to follow. Rosato and co-workers simulated it in 1987; Knight, Jaeger and Nagel saw the convection in 1993.

There is no single law for it, only that threshold and a lot of careful experiments. Shake Nutreon. He rises.

Equations

\[\Gamma = \frac{A\,\omega^{2}}{g} > 1\]
SymbolMeaningUnit
\(\Gamma\) dimensionless shaking acceleration (container acceleration over gravity) \(\mathrm{–}\)
\(A\) amplitude of the vertical shaking \(\mathrm{m}\)
\(\omega\) angular frequency of the shaking \(\mathrm{rad/s}\)
\(g\) gravitational acceleration \(\mathrm{m/s^2}\)

Sources

  1. Rosato, Strandburg, Prinz & Swendsen (1987) Why the Brazil nuts are on top: Size segregation of particulate matter by shaking, Phys. Rev. Lett. 58, 1038
  2. Knight, Jaeger & Nagel (1993) Vibration-induced size separation in granular media: The convection connection, Phys. Rev. Lett. 70, 3728
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