FACT: As you may well know from experiences with muesli or similar mixtures such as varying sizes of Lego bricks an odd thing happens when you shake them. the odd thing is that the largest, heaviest objects sit on the top. If they are not then they miraculously rise up through the mixture when it is all shaken. This is a problem, specifically the Brazil Nut Problem. It is a problem still, because it has not been solved.
Named after the large nuts which rise up to the top of Muesli the Brazil nut problem has bothered physicists for decades.
In 1987 Anthony Rosato tried to explain it by suggesting that when larger nuts rose it left opportunities for the smaller oat flakes to infiltrate the gap, causing the large nut to land further up each shake. However according to Sidney Nagel of the University of Chicago the explanation is incorrect. After studying the physics of the everyday for many years he has come up with his own slant on the Brazil Nut problem.
He believes that both larger nuts and the oat flakes rise up when shaken but then in the ensuing gaps between the objects the oat flakes can slide down the sides whereas the large nuts cannot do so as the gaps are too small. Meaning that after successive shakes the largest nuts end up on the top.
This, while a good explanation, is incomplete and Mr Nagel confirms it himself, saying that the problem always brings something new which ,’comes along to knock us out of our complacency.’
There you go, simple nuts confound even the best of us.
Click here for a video explaining this in greater depth