The Speed of Light

Sam E De La Torre Baba

The speed of light is the maximum velocity that anything can travel. The speed of light is commonly referred to as c and is 299,792,458 meters per second. This speed not only refers to the speed of light travels, but also the speed of any massless particle will travel. As of now, there are only two massless particles which are the photons and the gluons. Neutrinos (which as of recently have been proposed that they can travel faster than the speed of light) are assumed to be massless, however, the model for their oscillations require them to have nonzero masses. The change in which a gravitational field propagate will also be equal to the speed of light.

In our everyday lives, we observe light because light is what allows us to see. The light we see everyday though will not travel at the speed of light. This is because the light we observe has to travel through transparent mediums such as air, glass, or water. Every substance has its own refractive index which describes how light propagates through a certain medium. When light enters a transparent medium, light's path will be distorted, therefore, the speed in which light propagates through the mediums we see everyday will be slightly slower. The speed of light through this mediums is still very close to the actual speed of light due to the amount in which it slows down is almost negligible and will result in such a speed that can be considered instantaneous.

In electrical engineering courses, students are thought to assume that if all elements of a circuit are ideal, than one is to assume that a current can be found on all elements of the circuit immediately upon applying a voltage. By knowing light has speed, we know this is not precisely, but due to lights incredibly high speeds, this is negligible and circuit analysis results in being a very important tool for electrical engineers.

So, light seems to be of such high speed that it can be considered instantaneous. One can react to things in an efficient manner such that the speed of light can be unaccounted for. What if we are to observe this in a macroscopic way? The easiest way to do this is by going outside and observe the night sky. There are more stars than can be counted with an estimated 100 sextillion in our universe. To see these stars, light must have traveled from its origin (in this case the star) all the way to our planet. In this case, the star is very far away. So far away, that light can no longer can be treated as instantaneous, not even close to it. A unit of measurement was even created for us humans to be able to contemplate the vast distances between these celestial bodies, the light year. The light year is a unit of length which is equivalent to the distance traveled by light in a a single year.

Since these stars are so far away, we would have to go faster than the speed of light to get to them. But, I just stated that the fastest an object can go is the speed of light. So what would happen if one would go faster than the speed of light and why can't I go any faster? Lets remember Einstein's famous formula E=mc^2. This results in a relation between energy and mass using the speed of light as a constant. This equation allows us to conclude that the more energy an object has, the heavier it becomes, and can it can even be argued the more mass it has. So lets propose that one is riding a car that can go tremendous speeds that can is able to get close to the speed of light. As one starts passing the sound barrier, you can feel a force towards you, pushing you towards your seat. Faster, faster and faster and your getting closer to the speed of light. Everything is significantly heavier which results in your hair weighing much more than what you used to weigh before going the speed of light. As your speed approaches the speed of light, your weight will become infinite. To move an infinite amount of weight will require an infinite amount of force to move. This is the bottleneck. There is no way to obtain an infinite amount of force thus obtaining a speed faster than the speed of light impossible.