It seems that 3D is again all the rage. Not the red and green glasses variety that my Dad would have enjoyed in the 1950s but completely new technologies for our viewing pleasure. In fact, more than one technology and no industry standards, so that side of things looks like ending up a bit of a mess as usual.
With that on my radar, I’d been itching to try out the 3D baby scan. My wife’s expecting and, as it hadn’t been available last time around, I’d hoped we could give it a go. Unfortunately, it didn’t seem possible. We just ended up having the normal scan. So I mentioned it to the woman doing the scanning.
“Oh, yes, we can do that.”
She simply flicked a switch and there it was in a murky, yet distinctly 3D, appearance.
“No, it’s 4D,” said the woman. “4D?” says I. ‘Yes.” “Oh.”
That was that. I wasn’t in quite the right space to debate the point – doting over my unborn child and all – yet I couldn’t let it pass. Had the IT industry got it wrong? Is everyone mistaken when they say 3D? Well, yes ... and no.
In ‘regular’ space there are three dimensions – up and down, left and right, forward and backward. But for it to exist, a period of time has to elapse. So, in the space-time continuum, the time element is considered a dimension in itself. It is the basis for Einstein’s theories of general and special relativity ... and the fourth dimension our scanner person had been talking about. Now I get all that.
We’re right with our 3D definition – the fourth dimensional time thing is just a bit of a red herring. Otherwise, my flat, 2D computer screen would actually be 3D, which would get all very confusing. It’s actually got a name: Minkowski Space.
But talk to mathematicians and they’ll tell you there is a fourth spatial dimension, and has been for years. This space, known as four-dimensional Euclidean space, is the space used by them when studying geometric objects. As far as I can work out, it means that you can draw, say, a cube, and can see all the sides – a bit like a Picasso painting where all the features on the face are visible.
What puzzles me, however, is: isn’t this 5D? You know, 4D Euclidean combined with our friendly additional dimension, time.
Well, apparently it is. Five-dimensional space – and whether it actually exists – is a topic astrophysicists and particle physicists frequently debate.
But wait. There’s more. It turns out the universe would make more sense if we were living in a 10 or 11-dimensional realm, where gravity is bubbling off a different plane entirely. I’m reliably informed (by Wolfram Alpha) that this would solve a number of mysteries like mini-black holes and dark matter, gravitational waves and cosmic inflation, super-high-energy particle collisions and ultra-powerful gamma-ray bursts.
Oh boy, now my head really hurts. I think I’ll just stick to 3D.