It is also important to remember that science itself is simply the noticing and finding of the mechanics that make the physical world tick, everything they discover is already there, and many times it has had to rewrite itself in order to take on new learning and discovery.
It is wrong to assume that process is over and that there isn't anything round the corner that might turn it all on it's head again.
Even now science itself says that underneath, everything is energy, and they are struggling with theories such as string theory to explain this in a comprehensible form.
It has also been seen that theories get rejected even if they work but don't fit in with the 'current' theory. Scientists get mocked too.
There is an element of blind faith and speculation to it.
If everything is energy, then why shouldn't life exist in this pure form too?
Maybe it was here before the physical world.
If you want to get philisophical about it