NOTE: This is a very, very simplistic imagining of Einstein’s equation but should serve as a primer to how mass and energy are equals
And it is actually very simple when you understand the mechanics.
As we understand it, mass is simply condensed energy. A way to imagine it is as if it is water. Liquid water represents the energy. It can carve stone, erode whole rock faces as energy. Mass would be ice. Frozen, solid, energy. To calculate the amount of water (energy) in ice (mass) we use the equation ‘E=MC2.
Well that sounds all well and good but still meaningless unless we can turn that energy into mass or, as it is easier to replicate considering we have no fusion reactors on Earth, turn the mass into energy and measure the output – fission. Which we can do easily. Probably the best way to demonstrate this is in the inner workings of a nuclear bomb. A nuclear power plant would suit this demonstration also however a nuclear weapon is the most portent and impressive manner we have proved the equation.
So how does it work?
Uranium is a known unstable material. Uranium 235 is an isotope of Uranium that has an extremely unstable nucleus. Which is exactly what we want if we need to turn mass into energy as it does it by itself anyway. U235 emits detectable amounts of radiation which, in simple terms, is E=MC2 in action. U235 slowly turns its own mass into energy which we register as radioactivity. It emits it in amounts that can be measured using E=MC2.
But let’s go a bit more bombastic. If the nucleus of U235 is already unstable enough to emit radioactivity on its own surely we can speed the process up and have it release all that energy at once instead leaking it out over many thousands of years. Which is where a nuclear weapon comes in handy.
So how do we do this? Easy. Imagine the nucleus of a U235 atom as an overripe, slightly rotten, tomato which has still retained its surface tension. You know if you had one of these on your kitchen counter a mere stab with a fork would have you with a load of ruptured tomato all over the counter. Which is what the U235 nucleus looks like.
Inside a nuclear weapon is a sphere of U235, all very unstable like our tomato but in far greater numbers. So where do get out forks to burst these unstable nuclei? In the implosion. You see the detonator of a nuclear device surrounds the sphere of U235 and when it goes off it implodes the sphere into itself. All these nuclei are pushed together, piercing each other. One nuclei is pushing into the next and as these nuclei are unstable, like our rotten tomato, they split each other open and release the energy contained within. The mass of the nuclei splits – it goes from mass (M) and crosses the = into energy (E). The amount released is measured by 2 x the speed of light. E=MC2 is complete (though in reverse).
Our sun does the same but in reverse. It is a fact and independent of belief.