Excerpt from the book "The Future of Mind" by Michio Kaku.
There is no “Wall” separating the quantum world from the macrocosm, and the oddities of quantum theory may well creep into our “common sense” world. Wave functions never collapse - they endlessly split the universe into parallel realities.
The paradoxes of the microcosm (for example, the ability to be alive and dead at the same time, be present in two places, disappear and appear in another place) also enter our everyday world.
But if the wave function is constantly splitting, giving rise to completely new universes, then why can't we get into them?
Nobel laureate Steven Weinberg says it's like listening to the radio in your living room. Hundreds of radio frequencies from all over the world fill the room at the same time, but your receiver is tuned to only one frequency. In other words, your radio is "incoherent" to all other stations. Coherence is a condition in which waves vibrate in unison, as in a laser beam. Decoherence is when waves start to fall out of phase and can no longer vibrate in unison. Other frequencies also exist, but your receiver is not able to pick them up because we vibrate at different frequencies with them. They are "Unleashed" with us, that is, their fluctuations decohere from ours.
Likewise, the wave functions of a dead and live cat can decohere over time. From this, startling conclusions follow. You coexist in your own living room with the wave functions of dinosaurs, pirates, aliens and monsters. But you, fortunately, do not even suspect that you are sharing the same space with these strange inhabitants of quantum space, since your atoms do not vibrate in unison with their atoms. Parallel universes do not exist somewhere far away, no one knows where; they exist in your living room.