LONDON - Viennese scientists are trying to grasp the mysteries of the holographic principle: How many dimensions are there in our universe?

‘A hologram, as you find it on bank notes or credit cards, appears to show a three-dimensional picture, even though in fact it is just two-dimensional,’ Daniel Grumiller explained. He is at the Institute of Theoretical Physics, Vienna University of Technology.

For decades, scientists have been wondering about the existence of additional dimensions so far hidden to our senses.

Grumiller and his colleagues are trying the opposite approach: Instead of postulating additional dimensions, they believe that our universe could in fact be described by less than four dimensions.

Grumiller is currently working on gravitational theories which include two spatial dimensions and one time dimension. They can be mapped onto a two-dimensional gravitationless quantum theory.

Such theories can be used to describe rapidly rotating black holes or ‘cosmic strings’ - spacetime defects, which probably appeared shortly after the Big Bang.

In such a case, reality has fewer dimensions than we would think it appears to have. This ‘holographic principle’ plays an important role in the physics of space time.

Instead of creating a theory of gravity in all the time and space dimensions, one can formulate a new quantum theory with one fewer spatial dimension.

That way, a 3D theory of gravitation turns into a 2D quantum theory, in which gravity does not appear any more. Still, this quantum theory correctly predicts phenomena like black holes or gravitational waves, said a Vienna release.

We perceive the space around us as three-dimensional, in terms of length, width and depth or height. According to Einstein, time and space are inseparably linked. Adding the time axis to them makes our space-time-continuum four-dimensional.

Together with colleagues from University of Vienna, Grumiller is organising an international workshop, from April 14 to April 24. Scientists from Harvard, Princeton, the MIT reveal that the Viennese gravitation physicians are held in high regard internationally.