SortStack #203 — 2026-12-29

By weight · Order from lightest to heaviest.

1. A house sparrow 28 g

   House sparrows have followed humans to every continent except Antarctica — one pair even nested deep inside an English coal mine.

2. A full deck of 52 playing cards 94 g

   Shuffle properly and you have almost certainly created an ordering of the deck no human in history has ever seen before.

3. An average newborn human baby 3.4 kg

   Newborns arrive with about 300 bones; many fuse over the years down to the adult count of 206.

4. An adult red fox 5.2 kg

   Red foxes may use Earth's magnetic field to aim their famous pouncing dives — they prefer striking toward the northeast.

5. A standard car tire, without the rim 10 kg

   About a quarter of a tire's mass is not rubber at all — it is steel belts and textile cord hidden inside the carcass.

6. An upright piano 220 kg

   Inside is a cast-iron plate holding strings at a combined tension of roughly 18 tonnes of pull.

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