The Fourth Dimension

On Evangelization in an Age of Science

Another famous result of Einstein’s theories was spacetime, the idea that time is a dimension in the same way that the three spatial dimensions are. The idea is actually older, it goes back to Pierre-Simon Laplace (d. 1827), but Einstein made it mathematically consistent with the rest of his theories. Spacetime in this sense has four dimensions.

But are there only three dimensions of space? If you are sitting right now in a room without curved walls or ceiling you are sitting in a space defined by three Euclidean dimensions. Look up at the nearest corner: there you will see three surfaces, two walls and a ceiling, converge. Hopefully for this example your walls and ceiling are not sloped. In such a room all of the places where the surfaces meet are right angles. Can it be any other way? Can there be a fourth surface with a fourth right angle? Extensions of the walls past each other into other rooms or past the ceiling into another floor don’t count, they are still the same dimensions, just extended. A sloping ceiling also doesn’t count, that would be a fractal dimension, with a dimensionality of 2.5 perhaps, in between the 2 of the second wall or the 3 of the regular ceiling.

So, can there be a fourth physical dimension of space? The answer is, not in our universe. Yet our mathematics say it is possible, even long before Einstein, and our observations hint it might exist.

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When we observe the expansion of the universe we see something rather strange. It appears we are at the center of the expansion. The Copernican Principle says this cannot be true. Accepting the Copernican Principle would tell us that if we were to be anywhere else in the universe we would also see the expansion as if we were at the center. How can that be?

The Copernican Principle has been wrong once before, in that it predicted there is nothing special about our time, and the Big Bang proved otherwise. Perhaps it is wrong here too. If it is wrong then we need a naturalistic reason why (remember, “God did it directly” might well be true but it is not falsifiable). No one has imagined a good natural reason, as far as I know, for us being at the only center of the universe. But let’s explore the other possibility, that the observed center of the expansion is everywhere.

Take a rubber balloon and carefully draw some small dots on its surface with a marker. Pretend each dot is a galaxy. Now inflate the balloon. The dots all move away from each other. The 2D surface of the balloon flies away from the center of the balloon in a 3D expansion. The pretend observers in these galaxies cannot see the third dimension, it is outside their 2D universe. They all think they are at the center of their 2D expansion, no matter where they are.

By analogy the same process might be at work with us. Our universe is expanding in 3D space with no single center in sight. We might well be seeing the result of a 4D expansion that is outside our universe. This is the first hint that there might be a multiverse that we will never directly see.

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At the time of this writing many Christians are very skeptical about the possibility of a multiverse and a fourth dimension of space, for reasons we will look at in the next essay. This was not the case back in the 19^th century when the mathematics of 4D space was worked out. Popular Christian apologists of that time pointed out that solid bodies – people – could disappear from one location and reappear in another by translating through a fourth dimension. Material obstructions would be no hindrance. A resurrected Jesus could appear in a locked upper room with the apostles exactly as described in the Gospels via a 4D translation. There is an old almost-forgotten non-scriptural tradition that the birth of Jesus was effected by a very similar translation that preserved Mary’s physical virginity.

Fourth dimensional mathematics also permit bilocation, the ability for people to be in two locations at the same time, a phenomenon reported among saints from the 1st Century (Mary Jesus’s mother meeting in Spain with James the Greater while she was with his brother John in Ephesus) to the 20th (Padre Pio).

Of course, God is not obliged to make use of a fourth dimension of space for such miracles (moreover, would such things really be miracles in the classic sense? Aren’t they more ‘natural’ with a fourth dimension?). Fr. Dwight Longenecker is right: God can do whatever He wants, at least that which does not contradict Himself. Yet the knowledge that such a fourth dimension might be a divinely-ordered possibility could be a comfort to the restless inquiring minds of believers and non-believers alike.