M&M's obsession leads to physics discovery

CNN ^ | February 16, 2004

[Cultural Jihad]

Professors Paul Chaikin, left, and Salvatore Torquato used M&M candies to reveal fundamental principles governing the random packing of particles.

WASHINGTON (Reuters) -- Princeton physicist Paul Chaikin's passion for M&M's candies was so well known that his students played a sweet practical joke on him by leaving a 55-gallon drum of the candies in his office.

[Cultural Jihad]

If M&Ms pack themselves with a density of 68%, then a 55 gallon drum filled to the top with M&Ms contains how many pints of air?

[RunningJoke]

Physiclicious.

[Khurkris]

...gee...and I wasted all those years in Political Science...

[Khurkris]

...gee...and I wasted all those years in Political Science...

[FreedomFlynnie]

140.8

[Reaganesque]

Mmmmmm, Physics!

[SamAdams76]

Not too hard to understand, since oblate spheroids have flatter surfaces than spheres and so leave less room between them. And if M&M's were made out of perfect squares, they would pack nearly 100% of the container.

[Cultural Jihad]

Hey, there's still room for over 23 six-packs of these!

[supercat]

Not too hard to understand, since oblate spheroids have flatter surfaces than spheres and so leave less room between them.

If all of the oblate spheroids were oriented identically, I would expect them to pack to the same density as spheres. The density improvement comes I would think from the fact that the oblate spheroids can be rotated to fill in the nooks and crannies. As a very crude analogy, a 13-card bridge hand is more likely to have a 4-3-3-2 distribution of suits than 4-3-3-3 even though the latter would be more "uniform".

[Cultural Jihad]

Perhaps the hard edges of the cubes somehow act to maintain more space than the soft-edged M&Ms would, in a random fill. (?)

[RightWingAtheist]

Here are some useful links on the subject. Incidentally, the Prof.Denis Weaire mentioned in these articles in the same person who unwittingly gave Ira Einhorn a boarding room. He is also probably the most important Irish scientist since G.G. Stokes.

http://physicsweb.org/article/review/13/12/10

http://www.susqu.edu/facstaff/b/brakke/kelvin/kelvin.html

http://www.queenhill.demon.co.uk/polyhedra/wp/wp.htm

[FoxInSocks]

when poured randomly and shaken

I don't think cubes would occupy more volume under these circumstances, just speaking from experience. Of course, I haven't done any formal studies. :-)

[mikrofon]

Mars Inc., which makes M&M's

Hmmm --- and they're wondering what those spheroidal particles are that the Rovers are finding...

[PAR35]

13-card bridge hand is more likely to have a 4-3-3-2 distribution of suits than 4-3-3-3

I don't think so. A 13 card bridge hand is more likely to end up with 13 cards than with 12. 4+3+3+2=12.

[mlmr]

Not too hard to understand, since oblate spheroids have flatter surfaces than spheres and so leave less room between them. And if M&M's were made out of perfect squares, they would pack nearly 100% of the container

I am wondering about the aha moment here. It seems obvious....

[supercat]

I don't think so. A 13 card bridge hand is more likely to end up with 13 cards than with 12. 4+3+3+2=12.

How about 4-4-3-2?

Though I have on occasion gotten 4-3-3-2's. And of course, the infamous 4-3-3-2-1.

[Chewbacca]

This is cool info.

[PAR35]

How about 4-4-3-2?

That one I'll buy.

[nuconvert]

physics is fun Pong