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The Universe is Hostile to Computers

VeritasiumVeritasium
Education4 min read24 min video
Aug 31, 2021|25,341,816 views|707,405|35,386
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TL;DR

Cosmic rays, high-energy particles, can flip bits in computers, causing errors in elections, games, and even aircraft.

Key Insights

1

High-energy cosmic rays, originating from deep space, are a constant stream of particles that permeate the universe.

2

These particles can interact with electronic components, causing 'single event upsets' (SEUs) where a bit flips its state.

3

SEUs have been linked to various incidents, including unexplained vote counts, video game glitches, and potential aircraft system malfunctions.

4

While radioactive materials in chip manufacturing were an early cause of bit flips, cosmic rays are now a more significant concern for miniaturized electronics.

5

Protecting sensitive electronics, especially in space and aviation, requires specialized radiation-hardened components and redundant systems.

6

The sun's activity influences the intensity of cosmic rays reaching Earth, with lower solar activity leading to higher cosmic ray flux.

THE MYSTERY OF THE BELGIAN ELECTION

The video begins by recounting a peculiar incident in a 2003 Belgian election where a candidate, Maria Vindevogel, inexplicably received 4,096 extra votes – a number precisely matching a power of two (2^12). This mathematically impossible result prompted an investigation. Initial tests ruled out software bugs, leading experts to consider a more complex explanation. The specific number of extra votes strongly suggested a single bit flip within the computer's memory, changing a specific binary value and thus inflating the vote count.

DISCOVERING THE SOURCE: RADIOACTIVE MATERIALS AND COSMIC RAYS

The investigation into bit flips led to the discovery that early computer chips, particularly DRAM in the 1970s, were susceptible to errors caused by trace amounts of radioactive materials like uranium and thorium used in ceramic packaging. These radioactive isotopes emit alpha particles that could ionize silicon, flipping bits. This led chip manufacturers to be more cautious about sourcing materials. However, the Belgian election anomaly pointed towards a different, more pervasive source: cosmic rays.

VICTOR HESS AND THE BIRTH OF COSMIC RAY SCIENCE

The existence of radiation from space was first suspected by physicists like Theodore Wolf at the Eiffel Tower. It was Victor Hess, however, who conclusively discovered cosmic rays in 1912 through high-altitude balloon flights. He observed that radiation levels increased significantly with altitude, contradicting the assumption that radiation originated solely from Earth. Hess's work revealed a powerful, penetrating radiation from the sky, later identified as high-energy particles from outer space.

THE NATURE AND ORIGIN OF COSMIC RAYS

Cosmic rays are primarily composed of charged particles, mostly protons and helium nuclei, with high energies. While some originate from the sun, the most energetic ones come from violent celestial events like supernovae and black holes in distant galaxies. Their journey through space, often for billions of years, can be millions of light-years long. Because they are charged, their paths are deflected by magnetic fields, making it difficult to pinpoint their exact origin.

COSMIC RAYS AND THEIR IMPACT ON ELECTRONICS

When primary cosmic rays collide with Earth's atmosphere, they create a shower of secondary particles, including neutrons, protons, and muons. These particles can reach the Earth's surface and interact with electronic components. A single high-energy particle striking a transistor can cause a 'single event upset' (SEU), flipping a bit. This phenomenon can cause errors in computers, from minor glitches in video games to more critical failures in data processing and control systems.

REAL-WORLD CONSEQUENCES: FROM VIDEO GAMES TO AIRCRAFT

The impact of SEUs is far-reaching. The video highlights the case of a speedrunner experiencing an unexplained 'upwarp' in Super Mario 64, potentially caused by a bit flip affecting the character's height coordinate. While not directly responsible for unintended acceleration in Toyota cars, cosmic rays are known to cause crashes in supercomputers, particularly at high altitudes like those at Los Alamos National Labs. They also pose a risk to aviation, as higher altitudes mean increased levels of cosmic radiation.

AVIATION RISKS AND THE AIRBUS A330 INCIDENT

A significant example of the potential danger of SEUs in aviation is the 2008 Airbus A330 incident. A bit flip in the aircraft's air data inertial reference unit (ADIRU) may have mislabeled critical flight data, leading to erroneous alarms and a dangerous pitch-down maneuver. Unlike modern systems or the redundant systems on the Space Shuttle which could overrule such single-event errors, the A330's older systems lacked specific resilience requirements at the time of its construction.

PROTECTION AND RESILIENCE IN SPACE MISSIONS

Protecting electronics from cosmic rays is paramount for space exploration. The computer controlling the Perseverance rover on Mars, for example, is a 20-year-old radiation-hardened component designed to withstand significantly higher levels of radiation than ordinary computers. The development of radiation-hardened processors and the use of redundant systems, like those on the Space Shuttle which detected numerous bit flips during missions, are crucial for ensuring mission success and safety.

THE SUN'S ROLE AND GENETIC IMPLICATIONS

The sun's 11-year activity cycle influences the flux of cosmic rays reaching Earth. When the sun is more active, its magnetic field creates a protective bubble called the heliosphere, which deflects some of the more energetic interstellar cosmic rays. Conversely, during solar minimums, more high-energy cosmic rays can penetrate the solar system. Furthermore, the video touches upon the speculative but intriguing idea that cosmic rays might have played a role in genetic mutations throughout Earth's history, contributing to biological variation.

Common Questions

It's suspected that a single cosmic ray particle struck a transistor in the computer tabulating votes, flipping a bit from zero to one. This specific bit flip, representing 4,096 votes, inflated her total, as it was exactly a power of two.

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