物質如何變為能量？

物質如何變為能量？
One method is combinding the matter with its corresponding antimatter,
e.g. electron+positron = 2 gamma ray
Another method is nuclear fusion which the total mass of the system is reduced and changed into energy.
e.g. nuclear bomb explosion
The energy released is given by E=mc^2

能量如何變為物質？
There is no any method right now as I know.

E=MC2就好多人都知，但M=E/C2就唔係人人曉得。

You cannot change matter into energy by any artificial means. The equation E = mc^2 given in Einstein's Special Theory of Relativity only indicates the energy equivalence of mass. The Special Theory of Relativiy did say that there are artificial ways that mass can be changed to energy or vice versa.
The vast amount of energy released in nuclear fusion and fission, in fact, comes from the binding energy (the strong nuclear interaction force, which is the strongest force in nature ever known to human) in the nuclei of atoms.

世上萬物皆有能量,但因沒有途徑釋放而被儲存於物質之中
若有外界能量誘發物質產生能量,其物資便會因而把其本身儲存的能量由可儲存的型式轉換成一種可以釋放的型式釋放而釋放出來。
例如紙張和火種
紙張本身存有能量,我們稱成化學能,但本身化學能並不能釋出能量(化學能是儲存能量的型式之一),而當有火種燃燒紙張,火種的高溫誘發紙張釋放能量,其化學能會立即轉換光能和熱能(兩種型式的能量皆可釋放能量),並從而釋放能量出來。
不同能量的轉換是需涉及其他不同因素,甚至多於一個因素。例如燃燒紙張,除了紙張作為燃料及火種提供高溫外,還需要氧氣助燃,這便是火三角(fire triangle),是燃燒物質的三個必要條件。
其他的能量的轉換亦與此相近,只是涉及的物質及因素不同而已。

E=mC^2

where E= Energy(in J), m= mass of the object (in kg) and C= speed of light, (299792458m/s), which is a constant.