Question of the week: Do we have any scientific evidence for the existence of dimensions beyond length, width, height, and time?
My answer: There is scientific evidence for the existence of dimensions beyond length, width, height, and time. I review and document in some detail that evidence in chapter 3 of my book, Beyond the Cosmos, 3rd edition. Briefly, the space-time theorems establish that there is a causal agent, and hence reality, beyond the dimensions of length, width, height, and time. Also, physicists have demonstrated that there is not adequate room within three space dimensions for all the symmetries required by quantum mechanics, gravity, and relativity. Since we need quantum mechanics, gravity, and relativity for physical life to be possible, there must be more space dimensions beyond the three that we experience.
Given the constraints that the particle creation models must be consistent with cosmic creation models and that all four of the fundamental forces of physics were unified into a single force when the universe was extremely young and extremely hot, then the universe in which we live has nine dimensions of space. These nine space dimensions all rapidly stretched out (expanded) from the cosmic creation event. At 10-43 seconds after the cosmic creation event, gravity separates out from the strong electroweak force (the unified force of electromagnetism and the strong and weak nuclear forces) and six of the nine space dimensions cease to expand. The six space dimensions that stopped expanding are no larger today than when gravity separated out from the strong electroweak force. Their sizes remain about a hundredth of a billionth of a billionth of the diameter of an electron.
As for space dimensions beyond the universe’s three large ones and six very tiny ones, Einstein’s theories of special and general relativity imply that once physical observers are able to exist in the universe it will be impossible for those observers to physically detect anything beyond the universe’s space dimensions. Therefore, from the confines of our universe, we can only speculate about the nature of dimensions that may exist beyond the universe.
Readers interested in exploring extra- and trans-dimensionality further can obtain a copy of Beyond the Cosmos, 3rd edition. Anyone can get a free chapter of the book at reasons.org/ross.