E = mc2 is world’s most famous and probably the most beautiful equation. This equation is also known as the energy-mass equivalence and it was proposed by Albert Einstein in 1905 in his Special Theory of Relativity. Many people think that it is a difficult equation to understand. But the truth is that E = mc2 is a very simple equation. However, the theory that gave rise to this equation was really mind-bending and ground-breaking.
In E = mc2
E = Energy
m = mass
c = speed of light
E = mc2 simply states that the mass and energy can be interchanged. Mass can be converted into energy and vice versa. This means the computer or mobile phone on which you’re reading this article can be converted into pure energy. But exactly how much energy can your computer or mobile phone produce? The energy-mass equivalence gives us the answer. Mass multiplied by the square of the speed of light gives us the amount of energy that the given mass will produced if converted into pure energy.
Pure energy takes the form of electromagnetic radiation — and such radiation travels at a speed close to 300,000 kilometers per second. Electromagnetic radiation can be visible light or X-ray or ultraviolet ray or other such forms. The faster an object travels, the more energy it possess. As we know that pure energy travels at a constant speed (of 300,000 km/sec), we can easily find the amount of energy an object can produce.
Square of the speed of light
The exact speed of light is 299,792,458 m/s
The speed of light squared would be 898,755,178,736,817,64 m2/s2
Square of the speed of light is a huge number. Therefore, the E = mc2 equation tells us that even the tiny amount of matter can produce a massive amount of energy.
Let’s find out how much energy can 1 kg matter produce.
E=mc2 = 1 × (3×108)2 = 9×1016 Joules
That’s huge amount of energy! But that is, if we can really 100% convert matter into energy. But can we? Well, in order to do so, we would need conditions like extremely high temperature and pressure. Even higher than that of the core of the Sun. Therefore, it is obvious that on planet Earth we can not do a perfect conversion between mass and energy. Energy-mass equivalence is a theory which has been proven indirectly.
But, of course, if we somehow can do 100% conversion of matter into pure energy — we will get extremely high amounts of energy.