Guessing how many in a jar

Reveal Solution. The maths behind packing objects like those in a jar of sweets was first studied by Johannes Kepler in , after being asked by Sir Walter Raleigh about the stacking of cannonballs on the decks of his ships. The mathematical history of packing objects has been found to be much harder than anyone had anticipated.

The subject area is now called Granular Matter and covers a vast range of materials, from the packing of domestic products to industrial processes involving the movement of grains and pellets. A greater understanding of how granular matter moves, twists, spins and breaks is the key to how cost savings can be made during the production process.

Yet granular mathematics is still not fully understood and is an area of ongoing research and development. Here is a puzzle for you to try: If a jar has approximately 4 sweets along the width, 5 along the length and a depth of 12 sweets, how many sweets are in the jar? Convert the volume to milliliters. Step 2: Determine whether the candies are spheres Determine whether the candies are spheres. If they are balls, like gumballs or jawbreakers, they're spheres.

If the candies are round, but longer than they are wide, they are "oblate spheroids. Step 3: Find the volume of one candy Find the volume of one candy, also in milliliters. First, find the radius of one candy, either my estimating, using a tape measure, or by using vernier calipers, which will provide the most precise measurement. Round pi to 3. Or, for the more generous candy-maker, the reverse could work: "If you are a Charlie and the Chocolate Factory manufacturer, you could find a way to fit the most chocolates in your bag.

The study was published in the latest issue of the journal Nature. Scientific American is part of the Nature Publishing Group. Lynne Peeples is a freelance science journalist based in Seattle. Already a subscriber? Sign in. Thanks for reading Scientific American. Create your free account or Sign in to continue. See Subscription Options. Discover World-Changing Science. Get smart. Sign up for our email newsletter.