Senior Member
In the text below, taken from "Welcome to the Universe" by Tyson, I don't understand the of the colored part:

These 10^(10^124) universes range from ones that are scary, filled with mostly black holes, to ones that are exactly like ours but where your nostril is missing one oxygen molecule and some space alien’s nostril has one more.

Though I understand what it means, I don't get its sense. Thank you.
  • The simple fact that "black holes" are mentioned here tells me I may be way out of my league...

    Here's my try anyway:

    This sentence seems to come from a text about the possibilities of a multiverse (theory according to which there isn't a single universe, but rather a infinity of parallel universes. Needs some fact checking!)

    According to my understanding of this theory, each parallel universe features a different reality from ours. Some universes may have a very different reality (I'll let your imagination run wild on this one), or feature a very similar environment. When considering the latter, one could easily imagine a parallel universe with an almost identical reality except for one oxygen mollecule that is missing from your direct environment but exists in the environment of an alien species.

    I guess the multiverse theory assumes an equal amount of matter between all universes. So if in one universe your nostrils are missing one oxygen mollecule, this means it has to exist somewhere else, like in the nostril of an alien being.

    Hope this helps!


    Senior Member
    English - England
    I agree. But although 10^(10^124) universes is an unimaginably large number of universes, it is unimaginably far from infinite. So there's no reason to suppose that this nostril-differing planet must exist.

    I'm probably just being picky. :D


    Senior Member
    Thanks ShaggyVinny and heypresto. From what you two have just said I gather that what Tyson is getting at is that these multiunverses have some subtle differences. Am I right?


    Senior Member
    Nobody knows, really, but scientists believe that if at all the multiverse theory is ever confirmed and, if at all, we are ever able to even glimpse at the immense number of universes it contains, differences with our universe will vary from drastic differences (entirely different physical laws and number of dimensions) to entirely negligible ones - simply because in infinity everything that is even remotely possible will be a fact. :)

    Keith Bradford

    Senior Member
    English (Midlands UK)
    He is saying that, in such a theoretical multiverse, some universes are totally different [e.g. ours and a gigantic black hole] and some are almost identical [e.g. ours and one where just one single molecule has been displaced]. It would follow that many would be vaguely similar to ours.

    In fact, I believe, the need to balance such constants as gravity, light-speed, etc. would make most multiverses either quite similar to ours, or totally self-destructive within seconds. The big probability gap is between quite similar and near-identical. In the same way, on Earth, you can meet dozens of people who are quite similar to your Uncle Percy, but you'll never meet anyone who is identical to him, to within a single molecule.
    < Previous | Next >