sentences:  Electrical or magnetic interference inside a computer system can cause a single bit of DRAM to spontaneously flip to the opposite state.The majority of one-off ("soft") errors in DRAM chips occur as a result of background radiation, chiefly neutrons from cosmic ray secondaries, which may change the contents of one or more memory cells or interfere with the circuitry used to read/write them.The problem can be mitigated by using redundant memory bits and additional circuitry that use these bits to detect and correct soft errors.