I think this question is settled somewhere betweeen physics and philosophy and we surely can not find a answer that fits 100%, but lets talk about it.
While thinking about how the universe and its content raised up from nothing(wich is the most common theorem afaik) one must come to the implication that "if there's nothing", the first "thing" needet to create "something" is a difference. difference to what? To nothing of course, wich indeed is something.
This is paradox for sure, but let's keep that idea in mind.
If we observe a vacuum, we can observe fluctuations of energy inside. Since we are not able to create a true vacuum wich is not affected by any source of energy or matter, we can keep in mind that, in our environment, an man-made vacuum has potential to generate difference to itself.
We can not say that this is a princip in the not existing universe, but it's all we have. So the vacuum that generates a fluctuation is at another state as it where without. Now that there are different states wich are excluding each other, we could name that possibility of changing states "time", due in princible, time is nothing less than change of states.
Assuming that this state is not stable and colapse instantly, the universe would stay the vacuum wich fluctuates. But if from the fluctuate state another fluctuation could take place wich, while active, prevent the first fluctuation from colapse, we got a chance that the universe will not went back to its "nothing"-form.
I'm not talking about the probability of any event, but about the possibility(true/false), wich is enaugh at this moment.
So now let's say such a state could get kind of stable, not necessarily immune against colapsing, but strong enaugh to exist while not affected by anything else.
Now when the vaccuum, wich I from now call universe due it's not "nothing" anymore, keeps fluctuation and other "things" can appear, these can, but not must, react to the other thing(s) that exist. Some might destroy each other, some might alter each other and even other might absorb or combine.
This would lead to more complex things.
But now, what is a "thing" in this scenario? Well, I don't know. Let's say "everything that one could give a name". The first thing we got in this scenario was time, wich is quiet logical I think du it's necessary to seperate states from each other.
From now, everything is possible.
Now I claim that, depending on this scenario, everything that CAN raise, WILL raise. I would be happy if one can proof me wrong on this argument.
This Theory has some big problems:
(1) Does the universe still fluctuate?
(1.1)If yes, why don't we notice that?
(1.1.1)Are the fluctuations too small?
(1.1.2)Why is conservation of energy true, if there could raise new energy? (2)What about ultra-stable elements? Well,... I'm ambivalent about that. In one way this coud cause the universe to stop doing anything else due all potential would generate elements wich do not react to anything. But looking at the periodic table of the elements, it seems as like exactly this is happening.
What I like at this theory: (1) infinite scope: If something can raise, it will. Well, it still can vanish at other time. (2) no limit to speed of light: The limit is what exist. But new things can exist later and even if it the speed of light might be a limit at a time, it might not be at another time. (3) Evolutionary: If something arise it can be forced by other things to vanish, or reverse.