“The simple truth is that interstellar distances will not fit into human imagination. Even light, which travels so fast that it takes most races thousands of years to realize that it travels at all, takes time to journey between the stars”(Douglas Adams). Light is a very interesting concept, perhaps because our existence depend on it. But what exactly is it? Light could be described as a wave with a very small wavelength and a high frequency, or as a photon, which is an elementary particle similar to  a quark or a gluon. A light photon (or a wave) doesn’t posses any mass, and is constantly on a move, traveling roughly at about 299,000,000 meters per second, as a matter of fact, it could travel around our planet 7 times in the blink of an eye.

Overall, light is another word for electromagnetic radiation, which is a form of energy, and the most fascinating thing about energy is that it makes up everything. But wouldn’t that be atoms, you may think? The answer is yes, but there is a much bigger picture to that. Atoms, in point of fact, are also composed of energy. This energy is stored within elementary particles as potential energy, such as quarks that make up a proton. One of the founding fathers of quantum mechanics, Albert Einstein, derived an equation in his special theory E=mc2 which basically states that energy is equivalent to mass, and mass is a property of energy. It happens to be that C, a constant for speed of light is also equivalent to distance over time. In fact, the basic equation of V(velocity)=d/t was used to calculate the speed of light in 1676, and the result was very close to the actual speed that we know today.

Time, being one of the most used words in any language, plays a crucial role in our universe. It is important to accept the fact that time is relativistic in our reality, however it may exist in it’s own dimension. It is argued by many that time is a fourth dimension or a singular linear dimension of its own. In order to observe something is cosmos, the 3 dimensions are required to locate the coordinates, X,Y,Z, and time is used to locate the position of an object that travels through an ever expanding cosmos. Appropriately, spacetime concept was created. It could be inaccurate, however, to say that time is the fourth dimension since we know that there are 2 other observable dimensions to us, time is also likely to exist in them (that is if we consider the String theory). As a side thought, if we know that there are dimensions before ours (0d, 1d, 2d) and dimensions above (4d, 5d, ∞d), technically  every dimension expands into the dimension above (n+1). Albert Einstein described spacetime. Going back to matter, it is likely that mass is shaped by the spacetime continuum.

Matter itself causes the geometric curvature in spacetime fabric, therefore causing the objects to be attracted to each other. Based on this theory, it is not the gravitational force that acts upon an object falling down to the earth but the spacetime distortion that pushes it down. As was mentioned earlier, mass is shaped by the spacetime, so based on Higgs mechanism, an elementary particle moving through spacetime would be slowed down, and as a result be provided with mass and prevented from accelerating to the speed of light. E=mc2.