Ever since Albert Einstein developed the special theory of relativity in Zurich in 1905, by «fourth dimension» one usually means time. But how can one visualize a fourth spatial dimension – in addition to top-bottom, right-left and front-back?
In the arts Salvador Dalí tried that: his crucifixion scene painted in 1954 shows as cross consisting of the three-dimensional unfolding of a hypercube
in four dimensions (similarly to the unfolding of a cube into squares).
A completely different, but no less fascinating, look into the fourth spatial dimension was now obtained by two teams of scientists from Switzerland, USA, Germany, Italy and Israel. The ETH Zurich researcher Oded
Zilberberg, professor at the Institute for Theoretical Physics, played a pivotal role in both publications, which were recently published in the scientific journal Nature (doi:10.1038/nature25000).
He provided the theoretical basis for the experiments in which a four-dimensional physical phenomenon could be observed in two dimensions.
...A team of physicists led by Mikael Rechtsman at Penn State University and including Kevin Chen’s
group at the University of Pittsburgh in the USA has realized Oded Zilberberg’s idea by burning a two-dimensional array of waveguides into a fifteen-centimeter-long glass block using laser beams. Those waveguides were not straight, however, but rather
meandered through the glass in a snake-like fashion so that the distances between them varied along the glass block. Depending on those distances, light waves moving through the waveguides could jump more or less easily to a neighboring waveguide.
Author: Oliver Morsch, ETH, 1/4/2018
Contact: Paul Kovach