Interactive map of famous people named in the Panama Papers leak
Astrophysician Michio Kaku speaks with great clarity and insight about extraterrestrials and intelligent life, multiple dimensions, and the possibility of multiple universes.
Wikipedia: Michio Kaku, Extraterrestrial life, Multiverse
Michio Kaku' s talk is well presented.
We must remember, though, that theoretical physicists are not scientists but rather "science fiction" writers who predominantly use the very simple language of mathematics to generate their models. Their pronouncements are not generally evidence-based and, as as such, need to be taken with a very liberal pinch of salt.
Nevertheless the points he makes with regard to the ridiculous arrogance we have in assuming that higher order beings would wish to communicate or interact with us is very valid.
Indeed, in my book "Unusual Perspectives" I suggest that a "cosmic censorship" is more likely to apply with respect to nursery planets such as ours.
Peer to peer communications over a a very wide frequency range would, as Kaku suggests, have its merits but my preferred speculation is transmission at very low pulse rates having periods of days or months. These being more appropriate for inorganic denizens of space having vastly longer life-spans than the poor terrestrial bipeds that comprise our species.
It is when we come to the popular notion of additional spatial dimensions that has been kicking around in science fictions, both in mathematics and natural language, for decades that we need to take care. Because there is, as yet, not a single shred of hard evidence for the existence of more than the three spatial and one temporal dimension that we observe.
The (at present, I believe, 11 dimensions) favoured by string theorists, for instance, have no more real tangibility than the notions of Buddha or Jehovah, or hobgoblins, for that matter.
Like it or not, the unromantic idea of just the 3 dimensions we perceive is for the present, anyway, the only scientific reality.
On the other hand, while there is no direct scientific evidence for the existence of a multiverse, such a feature does seem to arise rather naturally from the overall empirical picture that we have built up of "the way things work". It is also more philosophically satisfying inasmuch as "bubble universes" overcome problems such as "what came before the big bang?"
The apparent "fine tuning" of physical constants that seem to uniquely permit life, especially when linked into the further "downstream" characteristics provided by the relative and timely abundances of the chemical elements and their compounds (as described in chapter 11 of "Unusual Perspectives") provide quite compelling evidence for the future direction of the process. A direction which is very compatible with a particular multiverse model.
"Unusual Perspectives" is available for free download from the eponymous website.