Why Albert Einstein Said That Nothing Can Travel Faster Than The Speed Of Light? | E=mc² | Einstein's Theory Of Special Relativity | Episode: 03


ALBERT EINSTEIN published his Special Theory Of Relativity in 1905. It presented the astonishing idea that space and time are not absolute but relative. Or simply put, changes in the measurements of distance and passing of time depends on the observer who is measuring them. Einstein then added a fourth dimension time to the three existing dimensions (length, width and height). In our previous 2 episodes we discussed briefly about light and space time. In case you haven't read the previous two episodes, go and enjoy them!



So, now what is relativity? A question that must have pondered upon your mind a while. Simply put, relativity is the dependence of various physical phenomena on relative motion of the observer and observed objects, especially regarding the nature and behavior of light, space, time and gravity. Hmmm... gravity. Gravity was given a new world by Einstein's theory of General Relativity.


Einstein revealed that time is experienced differently by observers in relative motion. Two events might appear as if they are happening at the same time for one observer, but they might happen at different times from the perspective of another. And the observers would be right in both cases.

Einstein later demonstrated this point with an experiment. Imagine a man standing on a railway platform as a train goes by. Each end of the train is struck by a bolt of lightning just as the midpoint of the train passes him. Because the lightning strikes are the same distance from the observer, their light reaches his eye at the same instant. Therefore, he would correctly say that they happened at the same time.

Meanwhile, there is an observer sitting in the exact midpoint of the train. From her perspective, the light from the two strikes also has to travel equal distances. She will therefore measure the speed of light to be the same in either direction.


However, as the train is moving, the light from the lightning that struck the rear must travel more to catch up and will be slower to reach than the light from the front. This causes the observer inside the train to conclude that lightning struck the front of the train first rather than simultaneously. Einstein says that simultaneity is relative.

These new ideas were published in a paper titled "On the Electrodynamics of Moving Bodies".

WHAT IS THE MOST FAMOUS EQUATION FORMULATED BY ALBERT EINSTEIN?


The magical and the most famous equation in the world, E = mc² is perhaps one of the most known scientific equations of all time. As you know, this equation came up in the fourth paper Einstein published in 1905. It states that energy is equal to the product of mass and the square of the speed of light. E=mc² where "E" is the Energy, "m" is mass and "c²" means the speed of light squared. Speed of light is 3 x 10^8 meters/second. 

This equation means that, matter can transform into energy if it moves fast enough. This theory perhaps led him say that nothing can travel faster than the speed of light and we will understand it in the next section.


One of the factors making this equation so remarkable is that it establishes a connection between seemingly unrelated entities. Before Einstein's fourth paper was published, time and space, and mass and energy were separate entities. But now we know that they are not different but the two sides of the same coin.

Through establishing the concepts of space time and E=mc², he formulated his theory of relativity. Though special relativity is one of the last intuitive theories ever made in the history of science, it turned out to be a crucial one for physics.

Scientists proved all the theories Einstein proposed in 1905. The uses of these theories did not always turn out to be for the benefit of mankind. Changing matter into energy is the principle behind the generation of nuclear energy which provides electricity to millions of people.

However, the same principle was used to split atoms and release the destructive energy of atom bombs. Thus, the equation which is a blessing in electricity production and medical diagnostic tools also became the foundation of the nuclear bomb.


WHY ALBERT EINSTEIN SAID THAT NOTHING CAN TRAVEL FASTER THAN THE SPEED OF LIGHT?
Let us now understand why Einstein said that nothing could travel faster than the speed of light. Now, applying what we know from the special theory of relativity, we get to know that E=mc² tells us that as mass speeds, time slows down. Basically if you are fast in space dimension, then you become slow in time dimension. And if you are fast in time dimension, then you become slow in space dimension.

Now, let's come back to the question. First you should know why light itself is the fastest. Yeah, couldn't it be something else? Why light is the fastest thing? But first of all, what is light? Is it a thing? Is it a motion? Clearly the answer seems to be a bit difficult. But let's clear it out. Light as we know is made up of tiny tiny particles known as the photons. Photon is a type of a Boson, which are more popularly known as force field carriers. Now, photons are field particles that are thought to be the carriers of the electromagnetic field. Therefore, photons have no MASS! But why is it astonishing? Because they move although they are MASSLESS!


And now, let's connect the dots. Einstein told that as you move, you gain mass. WHAT? Yes! But don't worry you won't become a fat person. And you know that it is not possible as well. Then, why did he said that? He actually meant that at great high speeds, and by great high speeds, I mean speeds near to the speed of light, there is so much kinetic energy that it gets converted into mass and the object starts gaining mass according to E=mc². Now, we know that light is made up of massless photons. Light itself is an electromagnetic wave.

Just think about it. According to E=mc², objects which have too much kinetic energy, starts gaining mass. But light here is massless, therefore it will not get mass itself in the first place! Because if photons gain mass, then they will no longer be photons or bosons. And that is why light photons can travel the fastest speed as they won't gain any mass at that particular speed i.e. 3*10^8 m/s. After that it may gain some mass. That's why light can travel till that speed.

Now let's tackle the next part of the question. Why can't anything travel faster than the speed of light? It's simply because everything in the universe has some mass. And if something has some mass, it will gain more if it travels fast. Even when you run on a road, while you are running, you are in kinetic energy, therefore you will gain very very very very small amount of mass as a result. But that's almost negligible.

So, now, if something gains mass, it would need more acceleration to maintain its speed. But more acceleration means more kinetic energy. And more kinetic energy means it will gain more mass. Therefore it is impossible to cross that speed as it will gain more and more mass.


So, that's why my dear friends, nothing can travel faster than the speed of light! But what if we created something special? Any hypothetical models/theories? Well, the answer is: YES...

Post a Comment

Next Post Previous Post