Part of the show The Christmas Q & A Show
John in Colchester asked:
I'm right in thinking that matter cannot be destroyed. So is it such that everything that has been created in nature, which creates matter, is still in existence somewhere somehow in another form?
It's not quite true that matter can't be destroyed. You may have heard of Einstein's formula E=mc2, which basically means that mass is the equivalent of energy. So you can convert mass into energy or energy into mass. But you can't destroy the total amount of mass and energy together. So the total amount of energy-mass stuff, that can't be destroyed. And that is always somewhere.
John - So everything that has ever been created in nature, is still in existence somewhere in some form?
Dave - Well, all of the energy in the universe is still there.
Chris - It originated in the big bang, which was the unleashing of a huge amount of pent up energy that existed in a tiny amount of space that was enourmously dense, and minute.
John - I'm thinking of matter created on earth like an acorn grown into an oak tree.
Chris - Well those are all atoms and those are all molecules, which are built from atoms, and the point is that all of the things and all of the complex elements you see here on earth must have been made in a star somewhere else in the universe. Nothing that was produced in the big bang came out more complicated than Hydrogen, Helium, and a little bit of Lithium. Which are the first three elements of the periodic table. And more complicated things were produced in stars like our own sun and bigger stars that very quickly ram things together and make very complicated elements which when the star blows up, are disseminated all around the universe. And then they gather together to make a new star, and new planets and things like our solar system.