Has your computer crashed? It could have been a cosmic ray

Every second, 100,000 particles called cosmic rays, traveling at nearly the speed of light, hit every square meter of Earth’s atmosphere.

These cosmic rays, after reaching the Earth’s surface, set off cascades of charged particles that fall to the surface.

When these particles hit the transistors of the microchip, they can cause problems and even crash the computer. These particle collisions are more likely to occur at higher altitudes.

As microchips become more ubiquitous and pack smaller transistors into increasingly tight spaces, engineers are hopeful cosmic rays are becoming a growing concern.

Somewhere in space, perhaps millions of years ago, an exploding star ejected a proton – one of many – from the cosmos. This particle, which travels almost at the speed of light, is called the cosmic ray.

He flew through space for years until, by chance, a blue-green planet crossed his path. To a traveling particle, the atmosphere of our planet was like a concrete block.

It crashed into one of the many molecules in our atmosphere, perhaps nitrogen or oxygen, triggering the creation of other particles – pions, neutrons, muons, electrons and positrons – to cascade across the planet’s surface.

Cosmic ray bombardment

Every second, about 100,000 cosmic rays strike every square meter of Earth’s atmosphere, but only about eight particles per square meter reach the surface. This constant rain makes up a small part of the “background radiation” that occurs naturally on Earth.

Cosmically charged particles reach almost everything: us, our family, our pets, and occasionally transistors in computers, tablets, smartphones or other devices.

When this latter event occurs, the accelerating particle can “flip” bits of data stored in memory, causing a minor software crash or even a system crash in rarer circumstances.

These “soft errors“, as they are called, do not cause permanent damage to the hardware, but may require a reboot to correct.

Physicist James F. Ziegler first discovered this effect of cosmic radiation on computers in 1979. Along with other researchers, they estimated that smooth cosmic ray errors occur about once a month for every 256 megabytes of dynamic direct access memory (DRAM) installed. Most modern computers have about 30 times this amount.

Ziegler and other IBM researchers also noted that certain places on Earth were exposed to cosmic bombardment with stronger rays.

Denver, for example, has four times more precipitation than New York, while cities in South Asia are less sensitive.

This variation it is related to two factors: the altitude of the place — the higher the atmosphere, the less protective — as well as the “stiffness” of the Earth’s geomagnetic field in that area.

Altitude is by far the biggest factor. While a computer underground may not sense slight errors, one in an airplane can sense anywhere from 10 to 300 times more, depending on the plane’s location on Earth.

Because NASA’s spacecraft operate outside the confines of Earth’s atmosphere, the US space agency has been aware of cosmic ray malfunctions for decades.

Space Shuttle had four computers manage the navigation and control of the ship, so if one should succumb to a serious soft error, the others would allow everything to work normally.

During the shuttle’s seven-day mission, NASA computer scientists noted about 100 soft errors. Most of NASA’s space operations now use computers with radiation-resistant chips, which contain transistors that are much harder to invert for cosmic rays. However, they end up running slower.

As microchips become more ubiquitous and fit smaller transistors into increasingly tight spaces, engineers predict that cosmic rays will become another concern for chip designers, posing technological hurdles that will have to be overcome.

This is especially important for computer systems in aircraft, for example, where an accidental failure could endanger hundreds of lives.

According to Bharat Bhuva, a professor of electrical engineering at Vanderbilt University, manufacturers may need to adopt NASA’s approach and redundancy design in your products.

For the rest of us, the answer to reducing the risk of cosmic rays on our computers is a strategy that’s been around for decades: constantly save everything that’s being done.

Alice Carqueja, ZAP //

Leave a Reply

Your email address will not be published. Required fields are marked *