At the end of the nineteenth century, many physicists felt that the theoretical advancements of the last three centuries had successfully produced a body of work that was fundamentally sound and that experiments over the next few decades would simpy added further details to that work. There were, however, a body of experiments that evaded interpretation with the theories of the day. As scientists struggled to understand these observations, the need for a new way of thinking became apparent and this led eventually to the quantum theory of today.

Here is a short look at some of these experiments which started people thinking in radically different ways.

• Cathode Rays
• Nuclear Scattering
• Atomic Spectroscopy
• Blackbody Radiation
• Photoelectric Effect
• Heat Capacity Anomaly

Or you can escape from this tour.