Energy

[2010PHS_Senior]

How did energy form if it cannot be created nor destroyed?

[MarkRae]

From the Big Bang, unless you're religious...

[2010PHS_Senior]

i am bt not really all into it. but there had to be some form of energy to caues an explosion so where did that energy come from?

[MarkRae]

From the Big Bang, unless you're religious...

[R1Geezer]

Like Mark says, from the big bang unless you are religious then some Geezer made everything in 6 days and then put his feet up, forever!

[vascop]

"Energy cannot be created or destroyed" only makes sense if your starting point is a position of non-zero energy. If you start with no energy then it has no meaning. So, if you like, it means that the total energy of the universe stays constant, but that constant is non-zero.

[jake-the-peg]

The idea that matter and energy cannot be created or distroyed is correct in the large scale world.

However in the very small scale and in extreme conditions things are a little different.

At the smallest level particles are constantly being created and distroyed in matter antimatter pairs. This is called pair creation. What looks to be a vacuum is in fact a constant turmoil of creation and anihilation

When these pairs form close to a black hole event horizon they cannot always recombine and are wrenced apart - this is Hawking radiation.

The point of all this is that when we use terms like "energy cannot be created or distroyed" we are referring to the large scale world of which most of us have our experience. Attempting to move from there to extreme events like the birth of the Universe and expecting physics to be exactly the same is a bit like getting into a formula 1 car and expecting it to work just like a family saloon

[vascop]

Since Einstein, mass is considered to be a form of energy. So an apparent loss of mass results in a gain in energy and vice versa. So the totality: mass plus energy, is conserved.

[Laasya]

You are right energy is not created nor destroyed but It is in the same form and May be from the Big bang.

[Symmetryigr8]

It shouldn't be like a formula 1 car and a saloon, that's the whole point of science, one set of laws that are able to comprehend and predict all behaviour under any conditions. At least that's the goal. As for the original question try and consider the idea of energy not forming but think of something else that's always been around. At the big bang it was converted into energy and mass in our universe. Something else that became our universe and all the stuff in it, if you like one step up the mass/energy/??? ladder.