The answer is simple: they don't.
Indeed, as of now, there isn't any evidence that universes other than ours even exist, let alone whether they have life.
At this point it's only speculation.
if they do find or make a wormhole, we can use it as a time machine and go to other universes.
yes there is other life forms because once they found frozen water on mars and water means life and we cant be the only life forms in the whole universe or Galaxy and there might be other universes to
This is just possibility, considered by some. It may answer the question, why our Universe has specific characteristics, some of which look like it is specifically fine-tuned to permit life: if there are multiple universes, others will have different characteristics, even a different number of dimensions - and out of this multitude of possibilites, a few universes have conditions suitable for life. There is no evidence for other universes, and if they do exist, it is not likely that we can have any contact with them.This is just possibility, considered by some. It may answer the question, why our Universe has specific characteristics, some of which look like it is specifically fine-tuned to permit life: if there are multiple universes, others will have different characteristics, even a different number of dimensions - and out of this multitude of possibilites, a few universes have conditions suitable for life. There is no evidence for other universes, and if they do exist, it is not likely that we can have any contact with them.This is just possibility, considered by some. It may answer the question, why our Universe has specific characteristics, some of which look like it is specifically fine-tuned to permit life: if there are multiple universes, others will have different characteristics, even a different number of dimensions - and out of this multitude of possibilites, a few universes have conditions suitable for life. There is no evidence for other universes, and if they do exist, it is not likely that we can have any contact with them.This is just possibility, considered by some. It may answer the question, why our Universe has specific characteristics, some of which look like it is specifically fine-tuned to permit life: if there are multiple universes, others will have different characteristics, even a different number of dimensions - and out of this multitude of possibilites, a few universes have conditions suitable for life. There is no evidence for other universes, and if they do exist, it is not likely that we can have any contact with them.
Parallel universes may, or may not, exist. While it is hypothesized that there may be other universes, there is no certainty that they do exist - nor, for that matter, is there any certainty that they DON'T exist. Since we don't know whether such "ohter universes" exist, we don't know what they look like either - although it has been speculated that other universes may have a different number of dimensions, or there may be other significant differences in physical laws, compared to our own universe. If this is the case, most such universes may be unsuitable for any sort of life.
Some theories allow for the possibility that other universes (some of which might have a different number of dimensions than our own) could exist, though it's generally believed that there is no possible way to actually observe these other universes.
Lots of different scientists test the same things to compare different conclusions.
There are thousands and thousands of other planets outside of our solar system, along with many other galaxies, universes, and planetoids, and possibly other forms of life.
It is thought that there are other universes that look like ours. It is also been suggested that there are an infinite number of universes.
There has been a lot of speculation about other universes, but it is just that: speculation. There is no firm evidence that other universes actually exist. Nor, for that matter, is there any firm evidence that other universes DON'T exist.
The idea of multiple universes is, like many other things, a theory. It could be true, it could not.
'Multiverse' is an abstract noun because by definition it is purely hypothetical. It suggests the possibility of other universes and by definition we could never physically interact with other universes even if they exist. Other universes are not perceptible to our senses. They are physically disconnected from our universe.
That is unknown. Some hypotheses based largely in mathematics have suggested that this is possible, but there is no direct eveidence that other universes exist.