Is cosmic radiation to blame for smartphone glitches?

We’ve all experienced the perils of a buggy phone or laptop – one that shuts down unceremoniously, without warning. Turns out, this could be the workings of space particles gone awry. Scientists at Nashville’s Vanderbilt University presented their findings, tellingly entitled “Control, Alt, Delete? The Impact of Space Weather in the Air and on the Ground”, at the summit of the American Association for the Advancement of Science (AAAS) last week.

While the Earth’s magnetic field largely shields humans from the potential damage caused by cosmic radiation, its impacts on our technological circuits are disruptive, the study suggests. Problems arise when a cosmic ray encounters a transistor; the high-energy particles have been known to cause “bit-flipping”, namely the transformation of individual bits of data within a computer’s makeup. The high-energy particles wield the capacity, for example, to change a binary 0 to a binary 1, and vice versa. These phenomena are known as single-event upsets (SEUs), and they could be what causes an app malfunction, or a random laptop shutdown.

In an attempt to quantify the disruption caused, the team at Vanderbilt University submitted a range of transistors to the glare of a neutron beam (used to emulate the impact of cosmic radiation) and then measured how many SEUs disrupted the data.

Bharat Bhuva, professor of electrical engineering at Vanderbilt University, announced to audiences at the AAAV: “Our study confirms that this is a serious and growing problem […] Through our research on radiation effects on electronic circuits developed for military and space applications, we have been anticipating such effects on electronic systems operating in the terrestrial environment.”

The problem, he stressed, is currently not particularly pervasive in everyday human life: “This is a really big problem, but it is mostly invisible to the public.” Nonetheless, he went on to explain as society becomes increasingly digitised, problems would continue to encroach, however incrementally, on the workings of everyday life: “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 […] In addition, microelectronic circuits are everywhere and our society is becoming increasingly dependent on them.”

Real world ramifications, whilst not directly harmful to human health, are an issue. A 2003 local election in Schaerbeek, Belgium, saw an SEU impact an electronic voting machine, inadvertently attributing an extra 4,096 votes to one candidate. Human health was also put at risk, albeit indirectly, when a Qantas passenger plane in 2008 made a drastic mid-air dive, plummeting almost 700ft in 23 seconds, causing several injuries.

Steps can be taken to minimise technological disruption, said Bhuva. He suggested that devices should be manufactured with three processors rather than one, so that if one of the transistors falls victim to cosmic tampering, the other two processors can collude to overrule the false one.

Meanwhile, if you think you can insulate your smartphone from SEUs using a particularly robust phone case, you’re right – if you’re willing to encase your sliver of a phone within three metres of protective concrete, that is.

Images: NASA Goddard Space Flight and Pabak Sarkar, used under Creative Commons