Exposure to the very high intensity electromagnetic fields found in the immediate vicinity of certain sources such as radar installations and TV or radio transmitters can produce electrical shock or a variety of heating effects, which may range from a sensation of warmth to burns and eventual cataract formation.
S 1 is a vertical, perfectly inelastic, supply curve. This represents 'momentary' supply. In most industries, if a firm was asked to produce a large order immediately, it simply would not be able to do it, regardless of the price offered for the order. Supply is perfectly inelastic in the very short run.
In the long run, as price and nominal wages increase, the short-run aggregate supply curve moves to SRAS 2, and output returns to Y P, as shown in Panel (a). In Panel (b), unemployment returns to U P, regardless of the rate of inflation. Thus, in the long-run, the Phillips curve is vertical.