this research was initially inspired by my governor’s school application for which the question was: “Discovery is the hallmark of science. Attach an essay describing one discovery in science or mathematics and the impact it has had on its field.” not only am I glad this prompted me to look into some of the most revolutionary scientific discoveries, but I gained a greater insight into the fundamental world of physics which I have always been incredibly interested in.
Before Einstein, astronomers understood the universe according to Newton’s Laws, which proved valid in nearly every application in physics and formed the basic understanding of mechanics and gravity. While Newtonian physics could describe things like motion, energy, and force, it could not explain the behavior of things that were very small or very fast, such as light. At age 16, Albert Einstein began to question this behavior and conducted multiple thought experiments in order to fill in the gaps that Newton’s Laws could not fully explain. By 1905, he proposed his theory of special relativity, which details the behavior of objects and particles moving similar to the speed of light.
Einstein stated that special relativity follows two postulates: the first being that the laws of physics must remain the same in every inertial (not accelerating) reference frame, and the second being that the speed of light (c) in a vacuum is the same for all observers. In order for both of these postulates to be proven true, we must rethink our understanding of space and time. So, let’s imagine a scenario: you are standing on a platform watching your friend pass by on a train that is traveling at half the speed of light. On that train, your friend has a laser that shines a beam of light directly in front of them to a mirror. From their point of view, the light moves straight towards the mirror and then straight back to them. However, as you are watching these events occur on the stationary platform, your perspective is different. You see the beam of light going to and bouncing off of the mirror, but as it is moving it is going diagonally, since the train that it is on is moving at half of light’s speed. Therefore, while your friend sees the shape of the light as a completely vertical line (bouncing from the laser and then straight back to them), you see it following a shape that looks like the top of a triangle.
Because speed (v) multiplied by time (t) equals distance (d), and the speed of light is always a constant, the two variables in this equation – time and distance – must change. The change of time is called time dilation. From your point of view on the platform, the light traveled a greater distance. Because vt = d, the beam of light must have traveled for longer. The amount by which time dilates for the beam of light is called gamma. Additionally, to compensate for the increase in time, the distance must then decrease, called length contraction. If on the train, your friend measures the distance between the very front of the engine and the very back of the caboose, it would actually be different than if you had measured the entire train from your point of view on the platform. This is because if something is moving relative to you, its length in the direction that it’s moving will seem shorter than it would if it wasn’t moving. To find the exact length of the object in motion, you divide the length at rest by gamma, which we found previously via time dilation. Length contraction happens for objects moving at a regular speed too, but it is so microscopically small you would never notice it.
By discovering the theory of special relativity, not only did Einstein introduce new formulas into the realm of physics, but he established that space and time are directly related. This had an extremely important effect on our ways of thinking and comprehending the universe. The language of all fundamental physics has since then been written in the terms defined by special relativity. Einstein’s discovery has had a seismic impact on the field of physics because it reimagined our view of the universe and the relationship between space and time.
VISUAL AIDS =
this image shows time dilation through a moving reference point which is the mirror on the rocket:
additionally, here is a nicer looking version of the formula to find the change in time for the moving reference frame, t’ can also be represented as gamma (γt₀)
at the time I wrote this paper I did not include my references so unfortunately I do not have a works cited. my main source of information however, was undoubtedly Mrs. Sadowski (my calculus and ap physics teacher) and the physics textbook she loaned me. (thanks mrs. sadowski!!!!)
<3,
blaire
blaire sheftel 