Question: why can't energy be created or destroyed , and if we are made out of energy how does it get transferrede when we die

Dan Porter answered on 6 Mar 2019:

Haha, this might be my favorite question so far! If only because I’m not sure it can be answered… but I’ll have a go!

Energy is always transferred from one form to another, or often to several others, say from the speed of a pendulum swinging, to the gravitational energy pulling the pendulum back down, plus the energy lost to heat through friction with the air and the bearing.

Another example is converting electrical energy into light in a light bulb, but some energy is also transferred to heat – as you’ll find if you ever try touching a 100watt bulb!

Yet another example is splitting atoms is a nuclear reactor – a uranium atom is split into two smaller atoms releasing more energy than it took to split the atom, but this energy comes from the fact that the two smaller atoms don’t weigh as much as the original uranium atom – mass has been converted to energy, which in this case is the motion of very fast neutrons.

In our bodies, we use chemical reactions between oxygen and sugars to allow our muscles to move and our brain and nervous system to work, these chemical reactions are transferring different types of chemical energies into motion,heat and electrical energy. So when we die, we stop breathing oxygen so these processes stop. Over time the chemical energy holding cells and bones together is transferred into other forms as bacteria causes them to decompose. So all the energy in our bodies is eventually recycled back into the universe and none is ever lost.

In all these examples energy is always conserved – no energy is created or destroyed, it is just transferred from one form to another, and this appears to be a fundamental law of the universe. If the universe didn’t work in this way things would look very different and it might not even exist at all!