Of all the theories in cosmology about how our universe was created, the braneworld theory presents perhaps one of the most exotic, hard-to-prove and yet potentially elegant solutions to how all this came to be.
The main idea here is that our three-dimensional universe is located on a brane (short for "membrane), which is a multi-dimensional object from string-theory. This brane of ours, say the scientists, is inside a hyper-dimensional space called the “bulk” or “hyperspace”. Interaction with extra dimensions and other moving branes can have an impact on our brane, with effects other cosmological models don’t account for.
In 1999, physicists Lisa Randall and Raman Sundry introduced a braneworld theory that received considerable attention. Under their theory, there can be other universes just a microscopic distance away from ours. But this distance “is measured in some fourth spatial dimension of which we are not aware,” explains Lisa Randall in her blog post explaining the ideas. Essentially, the visible universe is embedded in a larger universe.
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