Saturated fats and unsaturated fats are found in a variety of foods. The types of fats to consume if you are following a lipid-lowering diet has been the subject of some controversy. Some studies suggest that these all of these fats are not created equal.
Definition: A matryoshka (plural: matryoshki) is a Russian nesting doll. Nesting dolls are often used as symbols of Russian culture, but matryoshka dolls have their origins in similar dolls made in Japan. Matryoshka dolls are popular souvenirs.
The most obvious is that there is another Russian Doll, and the smallest particles are tiny billiard balls. If so, one day, perhaps with the Hadron Collider, we will see the size of the smallest objects.