Recent news that scientists have realized a quantum Hilbert hotel using a beam of light is indicative of the power of thought experiments, validated by simple experiments. Both interesting thought experiments as well as simple validation techniques are on the decline not only in Physics but also in other fields. In the Hilbert thought experiment, a hotel with infinite rooms, fully occupied, could make an additional room by shifting occupants one room up. More generally, the same hotel could make infinite empty rooms by shifting people to even number rooms leaving an infinite number of odd number rooms. The human brain that evolved through practical needs of Sapiens, has been lured into thoughts it was never designed to have.
Thought experiments on Infinity and zero (absolute nothing), such abstract concepts, are in a favorable direction to nourish the brain and perhaps move it into the next quantum state of knowledge. It takes no investment, no heavy machinery and not even high mathematics. It, however, takes imagination, something that has been draining out of humanity. Humans have been unable to internalize infinity and zero, perhaps because of the limitation of the brain but it is more likely because the brain gets inundated with the finite continuously. The thoughts that envelope the finite are mediocre at best and they are not extensible to the abstract nature of infinity or zero.
Thought experiments are possibly the best path to fundamental shifts in human knowledge.