The Earth's magnetosphere is what protects us from harmful radiation from the sun and other cosmic particles. Without the magnetosphere, there would be increased cancer rates, many navigational issues, and our atmosphere would be slowly stripped away by solar winds.
How the Earth's Magnetosphere was Formed
The Earth's magnetosphere is formed from the conductive metallic alloys from its core, mainly composed of iron and nickel, both ferromagnetic materials. The moving liquid metal generates magnetic fields because of Ampère's circuital law, while magnetic fields in the liquid iron generate more currents that move the liquid by Faraday's law. This feedback loop is called a geodynamo.
How Cosmic Rays are Deflected by the Magnetosphere
Cosmic rays get deflected by the magnetosphere using the Lorentz Force. The Lorentz Force causes charged particles to move in a way that is determined by magnetic fields. Most of the particles that are moving towards the Earth are charged protons (+) and electrons (-) from the sun, which gives the right conditions for the Lorentz Force to be exerted on the particles. The Lorentz Force exerts a perpendicular force onto the particles, causing the particles to spiral in the magnetic fields. Therefore, the Van Allen Belts and auroras borealis are created by the Lorentz Force.
How Cosmic Rays Could possibly Enter the Atmosphere
Even though most of the cosmic rays that are towards the Earth get blocked by the magnetosphere, highly charged cosmic rays with the energy of around 1 GeV, or about enough energy to allow a pea to cruise along at 0.25 millimeters per second. A proton that has the energy of 1 GeV, however, would be moving at 78% the speed of light (or 209.3 million miles per hour). A cosmic ray at this energy level can rip through, ionize atoms, and reach the Earth's surface. They also have a chance to alter the DNA in our cells. However, these are usually very minimal parts and are fixed by our bodies almost immediately. Since the Lorentz Force has less impact on higher energy particles, they are only weakly deflected and therefore most reach the surface of the Earth.
The GZK (Greisen-Zatsepin-Kuzmin) cutoff
However, there is a limit to how energetic particles (mainly protons) can get, which is around 5 × 10^19 eV, or around 8 joules. In comparison, 1 nutritional calorie (what you see on nutrition facts stickers) are around 4,184 joules. The reason why particles cannot be more energetic than this is because of the background microwave radiation of the universe from the Big Bang. When a particle goes over this energy level, it produces pions from the energy of the collisions with the photons, therefore losing energy.
The Van Allen Belts
The Van Allen Belts were first discovered in 1958 by astrophysicist James Van Allen, hence the name. When particles are deflected, they can end up in one of the two belts of radiation that surround Earth. Much of the radiation is trapped here, so most radiation doesn't reach the surface of the Earth.
How Bit Flips Happen
If you haven't watched The Universe is Hostile to Computers, which you definitely should, a bit flip can cause many different otherwise unexplainable glitches in computers, such as a plane crash, an altered speedrun, and a triggered election recount. When high energy cosmic rays hit the RAM (memory), changing a 0 to 1 or vice versa by disrupting the charges in the capacitor, or the place that stores the data. It can either add charge or remove charge from a capacitor, flipping the value.
ECC (Error Correction Code) Memory
However, there are always more answers than problems. ECC (error correcting code) memory was originally designed for many top-secret missions, eventually making it into consumer-grade DDR5 memory. Well, how does it work? In a nutshell, it adds extra bits calculated from the data already in the normal memory, so when something is off, it can quickly find and correct the error. However, there still is a downside to ECC RAM. It is mainly compatible only in server-grade hardware, not your everyday laptop. It also adds around 3% more latency, which would be negligible if your information was extremely important. In conclusion, without the magnetosphere, there would be more cosmic rays causing more bit flips to occur.
Conclusion
We are extremely lucky to have the Earth's magnetosphere; without it, life would be extremely difficult as the atmosphere would get slowly stripped away. Even though most particles are blocked, extremely high energy cosmic rays can still reach the surface of the Earth. With the swift advance of technology and space exploration, it is essential to understand the magnetosphere and the effects of cosmic rays without the magnetosphere where such shielding does not exist.
A Simplified Scratch Project that Simulates the Earth's Magnetosphere
Differences:
- You decide which rays are high energy
- The chances of bit flips are altered.
- Auroras do not form in a single cosmic ray collision, they form over many, many, particles, roughly 10^12 particles per meter per second.