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a few questions for relativity
a few questions for relativity
The first postulate of Einstein’s Special Relativity was at first known as the Principle of Relativity. This discovery was attributed to Galileo a few centuries before, that “the laws of physics are the same in all inertial frames“, or worded differently, that “all inertial frames of reference are equally valid“. This means there isn’t a universal frame of reference with which to measure the velocity of objects, that all objects exist and travel relative to all other objects, and any point of reference could arbitrarily be considered “stationary”. Actually, this is quite possibly the only truth found in Special Relativity.
So how to know how fast a given object actually travels? According to what frame? This seems initially easy to choose, since we live on the earth’s surface, this is the frame we almost always consider. Why would we choose any other frame? It’s the “obvious choice”. However, if we observe the positions of objects without the frame of earth, such as in outer space, the velocity of everything seems unclear.
How could we know the velocity of any one object in outer space? Understanding the implications of this simple question seems to “delve into” one of the original problems Galilean Relativity (which was Einstein’s first premise of Special Relativity) was thought of to solve. Whether that object is a planet, a star, a meteor, atom, particle, spacecraft, or anything else that physically exists within reality.
There seem a few ways to disprove Special Relativity. One way is to simply try to find the velocity of a given object. How difficult is that though? If we think we’ve found the velocity of an object, we could always ask, “what is that object’s velocity relative to?” We’ll find that there isn’t a “one and only” valid frame of reference. Any velocity of something is a velocity that is relative to something else.
This one simple consideration or question seems to illustrate the impossibility of how to know the position or velocity of a given object without direct reference to another object or frame. If a spacecraft is within highly minute decimal places away from reaching the velocity of light, traveling at a constant velocity, why isn’t the spacecraft essentially just as stationary as every other object that doesn’t accelerate within a given inertial frame? That a given object is also relative to literally all objects within every other perspective?
The “velocity of light” is often expressed through the use of the symbol “c”. So what if there’s a spacecraft traveling near c, almost reaching c, and while almost there, it simply starts to somewhat “coast” at a constant velocity? How is this spacecraft experiencing a “coasting effect” within an inertial frame, different from how another object in outer space may exist, through its own inertial frame traveling at a constant velocity, of which we could theoretically say is just as “stationary”? What could prevent the spacecraft from existing and traveling within other different, yet valid, inertial frames? Throughout the universe, a given object that travels at a constant velocity is essentially just as “stationary” as any other object that doesn’t accelerate.