The many worlds theory relies on a rudimentary (flawed) understanding of quantum mechanics. Quantum just means very, very small scale – to us. Just because our optics (one of our weakest senses) are incapable of perceiving the interactions of certain atoms in certain situations (the particle/wavelength problem, for example) due to the scale, based on obvious first principles we can determine the activity matter if it were to manage to somehow harness the infinite energy required to manifest every reality in ‘imaginable and non imaginable’ potentiality. Again, to keep things simple energy either manifests in a positive or negative state. Positive meaning it is moving toward it’s casually/deterministically intended path, negative meaning it is deviating from that. Because of that, matter at microscopic and smaller levels is in constant flux.

The result is essentially the manifestations we experience, electromagnetic fields – gravity. For the many worlds theory to make sense, negatively charged energy could not exist. Everything would be positive, meaning not that everything happens all the time, everywhere – it means the exact opposite. Every manifestation of reality on any measurable dimension would cancel itself out, because there is equal amounts of energy on every layer of reality expressing itself omnidirectionally. To picture to result, imagine a cartesian grid on as many dimensions as you are able to fathom. Every plottable point in the grid would function like a positively charged magnet. Would anything EVER move?

Seriously, two paragraphs.