Half lives are incredibly consistent because of the incredible number of atoms involved. Half lives are a statistical property of a material. All we can say about individual atoms is that, over a certain period of time there is a 50% chance that they will decay, but nothing actually cause a particular atom to decay at a particular time.
Again, we don't know the mechanism but that's not in itself reason to presume there isn't one. If it were random, the half-life for all materials would be the same, but it isn't - some materials decay significantly faster than others, which means there has to be a mechanism involved somewhere.
In fact, at the level of quantum mechanics, the notion of cause and effect isn't really useful. There are simply events and interactions.
There's some interesting - and highly speculative, I'll grant - work being bandied about on the fringes of quantum mechanical research that's showing some promising mathematical results when time is removed from the equations at the quantum level. As I understand it, it doesn't work for all interactions, and it throws up other issues, but it's an intriguing idea that some quantum activity is outside of time: in which case, of course, the idea of cause and effect would need to be heavily modified at the very least.
So when Vlad claims that everything in the Universe has a cause, he is actually talking bollocks just like his absurd suggestion that the Universe is inside the Universe.
To be fair to Vlad, it's my argument in this instance that is predicated on the idea that every effect has a cause, and that it's therefore reasonable to deduce an infinite chain of events stretching back. Even at the quantum level, whilst cause and effect might be co-temporal, they are still interwined.
I haven't intended to give the impression that the universe is in the universe, but inside a broader reality of some description.
O.