Coconut water pulp ("meat"). In young coconuts, the liquid and air may be under some pressure and may spray slightly when the inner husk is first penetrated. Coconuts that have fallen to the ground are susceptible to rot and damage from insects or other animals. Plain coconut water has long been a popular drink in tropical countries, where it is available fresh, canned, or bottled. Coconuts for drinking are served chilled, fresh, or packaged. They are often sold by street vendors who cut them open with machetes or similar implements in front of customers. Coconut water for retail can be found in
Fermi liquid theory non-interacting fermions), and why other properties differ. Important examples of where Fermi liquid theory has been successfully applied are most notably electrons in most metals and Liquid He-3. Liquid He-3 is a Fermi liquid at low temperatures (but not low enough to be in its superfluid phase). Helium-3 is an isotope of helium, with 2 protons, 1 neutron and 2 electrons per atom. Because there is an odd number of fermions inside the nucleus, the atom itself is also a fermion. The electrons in a normal (non-superconducting) metal also form a Fermi liquid, as do the nucleons (protons and neutrons)