No analogy is perfect. They are intended to help illustrate a concept to gain insight. Ideally when using an analogy its limits should also be described. Luckil

No analogy is perfect. They are intended to help illustrate a concept to gain insight. Ideally when using an analogy its limits should also be described. Luckily the very first link after the analogy is explained does just that: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir3.html#c1 http://hyperphysics.phy-astr.gsu.edu/hbase/electric/watcir3.....