Consumers are quick to blame the manufacturer, but many computer crashes, file corruption and other operational failures may actually be caused by cosmic rays that originate from outside the solar system.
“This is a really big problem, but it is mostly invisible to the public,” said Bharat Bhuva, who described the issue in a presentation Friday at the annual meeting of the American Association for the Advancement of Science in Boston.
Upon striking the Earth’s atmosphere, cosmic rays traveling at fractions of the speed of light create streams of secondary particles, including alpha particles and energetic neutrons. While these particles do not produce known harmful effects to living organisms, some of them produce enough energy to interfere with microelectronic circuitry and can alter individual bits of data stored in memory – known as a single-event upset, or SEU.
“When you have a single bit flip, it could have any number of causes; it could be a software bug or a hardware flaw, for example,” Bhuva said. “The only way you can determine that it is a single-event upset is by eliminating all the other possible causes.”
Bhuva listed several incidents that illustrate how significant the problem can be. One such incident occurred in 2003, when a bit flip in an electronic voting machine in the town of Schaerbeek, Belgium, gave 4,096 extra votes to one candidate. The error was only identified because the candidate received more votes than were possible.
In 2008, the avionics system of a Qantas passenger jet flying from Singapore to Perth appeared to suffer from an SEU that disengaged the autopilot. This caused the jet to dive 690 feet in 23 seconds, injuring about a third of the passengers. There have been a number of unexplained glitches in airline computers, some of which experts chalk up to SEUs.
Bhuva is a member of Vanderbilt University’s Radiation Effects Research Group, which was established in 1987 and initially focused on military and space applications. Since 2001, the group has also been analyzing radiation effects on consumer electronics, studying this phenomenon over the past eight generations of computer chip technology – including the current generation that uses 3D transistors that are only 16 nanometers in size.
The 16-nanometer study presented Friday was funded by a group of top microelectronics companies that includes Cisco Systems, AMD and Qualcomm.
“The semiconductor manufacturers are very concerned about this problem because it is getting more serious as the size of the transistors in computer chips shrink and the power and capacity of our digital systems increase,” Bhuva said. “In addition, microelectronic circuits are everywhere and our society is becoming increasingly dependent on them.”
Aviation, medical equipment, transportation and other industries are aware of the problem and are taking steps to address it, according to Bhuva.
“It is only the consumer electronics sector that has been lagging behind in addressing this problem,” he said, adding, “This is a major problem for industry and engineers, but it isn’t something that members of the general public need to worry much about.”