Low-energy laser (LEL) weapons are less powerful and more portable than the high-energy variety. These weapons most often use a multicolored laser that oscillates among as many as five colors. This laser temporarily or, in extreme cases, permanently blinds people. Isotropic radiators are special munitions that illuminate or bloom with laser-bright intensity that causes the same retinal or optical damage as LEL. A nonnuclear electromagnetic pulse can be created by powerful developmental beam generators. This can disable communications, navigation, data processing, and computer systems. The high-power microwave is a directed energy system that "melts down" unshielded electronic systems. Infrasound is a powerful, ultra-low frequency sound that, when directed at persons, causes them to be disoriented and nauseous. Liquid mental embrittlement agents chemically change the molecular structure of metals or alloys, severely weakening them. Supercaustics are acids that can be concocted to be magnitudes more caustic than hydrofluoric acid. They may be applied to surfaces to deny human or mechanical contact. Antitraction technology involves the entire spectrum of superlubricants. This technology makes a surface so slippery that it is nearly impossible to pass over it. Polymer-based superadhesives can be applied directly on weapons, equipment vehicle, or facilities to alter or deny their use. Combustion alteration technology consists of chemical additives that either contaminate or change the viscosity characteristics of fuel to degrade air- breathing engine performance. Calmative agents are sedatives or sleep-inducing drugs. Visual stimulus and illusion include several technologies such as the Bucha effect, which use high-intensity strobe lights that flash at or near human brain wave frequency to cause vertigo, disorientation, and nausea.