Author: Emily Jiang
Editors: Flynn Ma and Jaylen Peng
Artist: Jade Li
A spacecraft blasts through space at the speed of light, reaching faraway planets in seconds–this is the dream for many sci-fi fans. But will traveling at light speed ever be possible? Traveling at light speed means traveling as fast as light (186,000 mi/sec); at this speed, reaching the moon would take just 1.3 seconds. Traveling to planets would be much more convenient if humans could reach such speeds. And how can we reach these speeds?
In short, traveling at the speed of light is not possible with our current understanding of science. This is because to accelerate an object to the speed of light, you would need an infinite amount of energy. And it’s impossible to acquire an endless amount of energy because as objects get faster, they will gain mass, becoming heavy, needing further energy to increase the object's speed. The only things that can travel at the speed of light are the massless particles that makeup light. With Earth’s gravitational pull, the acceleration due to gravity on Earth is 9.81 meters/second^2, and even with that acceleration, it would take 2.65 years to reach 99 percent of the speed of light.
Theoretically, however, we could get close to the speed of light. The first way is through electromagnetic fields: the force that keeps magnets on the fridge. The electromagnetic fields will accelerate charged particles, resembling how gravity pulls objects with a mass close to light speed under the right circumstances. The second way is by magnetic explosions; when magnetic fields collide, they may become tangled, and tension increases so much that the lines will snap and eventually realign (magnetic reconnection). Then, the fast change in the region’s magnetic field creates electric fields flinging attendant charged particles at immense speeds. The third way is by wave-particle interactions, which is when electromagnetic waves interact with each other. When these waves run into each other, their fields get compressed, accelerating particles at high speeds. Wave-particle interactions may also account for accelerating some cosmic rays that originate outside our solar system. When a supernova explodes, a hot, dense shell of compressed gas (blast wave) gets created and ejected away from the stellar core. In these bubbles, wave-particle interactions can launch high-energy cosmic rays at 99.6 percent of light speed.
While achieving the actual true speed of light travel may not be possible from our current standpoint, we can theoretically achieve near-light speed in many ways.
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