Hawking and other have proposed that baby universes can bud off from the body of the main universe at a wormhole or other singularity type event.
If each baby universe is then free to expand as our universe did and presumably if the right laws of physics apply in that new universe stars and galaxies can form then how does this fit in within the confines of conservation of energy?
As energy and matter are effectively interchangeable the energy to form the stars and galaxies in the baby universe must come from somewhere, if it can’t come from our universe, which I suspect it could not then where does it come from? Would it be possible to detect loss of energy from our universe to another.
So where does the energy to create a new big bang in the baby universe come from.
Also once it has budded does the baby universe maintain any connection to ours or does the wormhole cease to exist and the universes separate?
Agreed, but I’m just trying to see if we know where the energy came from. Was it some form of quantum fluctuation of the vacuum?
As an additional question, how do we know that ours was the first big bang, if you are correct it is entirely possible that we have budded of from another universe.
Aye, I just wanted to point out that if we can accept that our energy came from nowhere, we should also be able to accept that same possibility for other universes. Why do the other universes have to be connected to ours in any way?
And maybe ours was just one out of a trillion big bangs, all of which occurred inside a great vacuum, which itself was just one of a trillion great vacuums, etc.
But… back to reality I’ll say no more. This is a question for the smart people.
It’s a bit non-intuitive, but when you add up all the energy in our universe, including contributions from gravity as well as from matter, the total energy actually seems to be close to zero. Creating a universe may not involve using up any energy whatsoever. This recent Prospect article by Michio Kaku tries to explain this a bit - scroll down to “Create a baby universe” section.
Depends on the details of the specific model being proposed. Baby universes in general remain very speculative and different theorists get mileage out of playing with different versions of the basic idea.
Pretty much everybody proposing that baby universes can be created will also buy into the idea that our universe was created in just such a way. Once you start thinking in these terms, it becomes very difficult to suppose that we’re the first.
As one example, Lee Smolin has used the idea to suggest that, in giving birth to offspring via black holes, generations of universes evolve towards ones particularly suited to life. In doing so, he’s suggesting that ours is a particularly “late” example, with lots of ancestors.
Thanks Bonzer the Mitchio Kaku article pretty much answers my question. I still have not got around to buying his latest book yet. Though he does give good lectures.
I’ll say no more. This is a question for the smart people.