Our world does not stand still, every second changing and developing. Physical quantities and market quotations make fluctuations. Thanks to fluctuations there are bankrupts whole enterprises, electric current proceeds, there is sunlight.
Fluctuation is a mathematical deviation of size from average value (or the expected value of an average). A classical example of an oscillatory system is the mathematical pendulum. The cargo suspended on thread deviates on a certain corner position of balance and is released. At the expense of a stock of potential energy, cargo begins to make fluctuations from one party in another
Fluctuations in physics
Fluctuations in physics are divided into two big groups: forced and free. The forced fluctuations happen under the influence of periodically changing force. Free fluctuations arise because of an initial deviation of any element of a system from a balance point. In reality the free fluctuations always fade because of friction force or dissipative forces (for example, upon transition of energy to warmth).
Fluctuations in economy
Today's market - alloy of variability of sizes and indicators. Rates of exchange, bonds, stocks, costs of liquid goods (oil, gold) continuously change. In the ancient time fluctuations of the market were minimum. Before emergence of money there was an exchange economy - 1 kg of fowl could be exchanged for 1 kg of cheese or grain. Metallic currency brought small dynamics, but there was no need for fast price fluctuations. With the advent of paper money the need for market control appeared. The governments often printed more money, than it was required that led to depreciation of money. Today exchange rate is tied to policy, share price - to a situation in the market. Fluctuations promote emergence of "the effective market" on which the "wrong" prices are quickly adjusted by exchange speculators - traders.
The theory of "antifragility" - one of the latest scientific abstractions. According to this fundamental theory, everything existing in our world can be carried to one of three classes: "fragile", "impregnable" and "anti-fragile". "Fragile" is meant as the systems falling into decay as a result of fluctuations, "impregnable" as a result of fluctuations does not change in any way, and anti-fragile "fluctuations" do well. Protection against fluctuations in the world of "antifragility" seems not in creation of the systems predicting changes, and in creation of the impregnable and free systems seeking for small fluctuations. Risks all the same will not manage to be excluded from more and more dynamic life therefore it is necessary to study again and again to learn lessons from any mistakes, but not to try to predict them and to avoid absolutely.