More Naturalism in Experiments

Anu Venugopalan

The double slit interference experiment has been famously described by Richard Feynman as containing the "only mystery of quantum mechanics". The history of quantum mechanics is intimately linked with the discovery of the dual nature of matter and radiation. While the double slit experiment for light is easily undertsood in terms of its wave nature, the very same experiment for particles like the electron is somewhat more difficult to comprehend. By the 1920s it was firmly established that electrons have a wave nature. However, for a very long time, most discussions pertaining to interference experiments for particles were merely gedanken experiments. It took almost six decades after the establishment of its wave nature to carry out a 'double slit interference' experiment for electrons. This set the stage for interference experiments with larger particles. In the last decade there has been spectacular progress in matter-wave interefernce experiments. Today, molecules with over a hundred atoms can be made to interfere. In the following we discuss some of these exciting developments which probe new regimes of Nature, bringing us closer to the heart of quantum mechanics and its hidden mysteries.

Erwin Schrödinger

Huei Peng

Photon chamber ---Showing Particle Nature of Light in ---Showing Particle Nature of Light in 2D-2D-Grating Wave Experiments Grating Wave Experiments

M. A. B. Bég

F. J. Duarte

In chapter 2 of Quantum Clear we provided our answer to the all important question What is physics? And we concluded that the crux of it all is Nature . Furthermore, we reaffirmed the implicit dictum, known even before the time of Newton, that the experiment is the voice of Nature. That is how Nature communicates with us. Hence, it is important to recognize that … the experiment is the ethos of physics . From a quantum perspective, this is only natural since quantum mechanics was born from the experiment (Planck). Not only that, but as expressed by Born, the principles of quantum mechanics ‘were found by a slow and tedious process of interpreting experimental results.’ Here, it is from this perspective that we look at general trends in physics, theoretical physics in particular, and we conclude with a simple observation: it is time to return to the old ways, it is time to return to the experiment .