Physics and chemistry have produced two basic laws of thermodynamics that are obeyed by all forms of matter and energy, including living organisms. The first law is that of conservation of matter and energy, which states that matter and energy cannot be created or destroyed. Matter and energy can be transformed, and energy can be converted from one form into another, but the total of the equivalent amounts of both must always remain constant.
The smallest, thinnest needle is the nano 4mm, 32 gauge needle. By comparison, this needle is thought to be as thin as two strands of hair. The risk of injecting into muscle tissue is very rare when using this needle.
The nonserious use of nanosecond is probably much more common than the proper technical use. In measurement terms such as nanosecond, nanogram, and nanometer, nano- means billionth; in other kinds of words, its meaning isn't quite so precise. In computers, the speed of reading and writing to random access memory (RAM) is measured in nanoseconds.