> Veritasium. The Universe Is Hostile to Computers. 2021. YouTube, <https://www.youtube.com/watch?v=AaZ_RSt0KP8>. # The Universe is Hostile to Computers - On May 18th 2003, the Belgian election was held with computer voting, but an error happened during vote counting: in the municipality of Schaerbeek, a candidate received 4,096 more votes than was possible. - Single Event Upset (SEU): when a transistor's state switches from 1 to 0 due to alpha particle emission caused by radioactive elements. Those are soft errors: they leave no trace. - Cosmic rays mostly come from supernovae and black holes. They are made of protons, hydrogen nuclei or heavier nuclei, which usually collide with air molecules high in the atmosphere, creating new particles like pions, and then smaller particles. - It is probably one of those particles which flipped the bit of the transistor. - A similar occurrence is suspected to have happened during a speed run of Super Mario 64 by DOTA_Teabag.[^1] - Now, computer chips are made resilient against bit flips, but you cannot prevent them from happening. The main culprits seem to be neutrons. - Radioactivity increases with altitude: what about plane computers? - On October 7th 2008, a plane suddenly pitched down, making passengers experience -0.8G of acceleration. 119 people were injured from bumping their heads into the ceiling. The event is thought to have been caused by an SEU. - In space, astronauts who are hit by cosmic rays in the eyeball or optic nerve see a flash of light. - The cosmic rays emitted by the sun act as a barrier, the heliosphere, against cosmic rays coming from all around the universe. The sun has an 11-year activity cycle, and we can observe that cosmic ray activity is much higher when the sun is dormant. [^1]: [TTC Upwarp Highlight](https://www.youtube.com/watch?v=bhBf5crp0i8)