It would be a mistake to think that all of this effort is a colossal waste of time and money. There is a famous story about Queen Victoria visiting J.J. Thomson's laboratory after he discovered the electron. She asked,"Of what use are these electrons?" I've heard two versions of his reply:
"I do not know, but rest assured that some day you will tax it".
I think that this is a little cheeky, even for a professor, so I prefer the next response:
"Madam, of what use is a new born baby?"
Physicists themselves sometimes fall victim to Queen Victoria's attitude. I was once utterly astonished to meet someone who was using pion beams as a practical tool for cancer therapy -- the same particles which I had been struggling to understand at a theoretical level for several years!
The following is an image of a human brain which distinguishes white and grey matter as well as cerebral spinal fluid. It was created with MRI (magnetic resonance imaging; what used to be called Nuclear Magnetic Resonance, but apparently the word "nuclear" frightened people). The method creates an image by analysing signal associated with the spin of the protons making up the patient's brain.
Researchers have used small proton accelerators as new tools in the fight against cancer. The image below shows the benefits of using crossed proton beams to concentrate distructive energy on a tumor in the prostrate gland (as compared to traditional X-ray beams in the top two photographs). Further information may be found at the Nuclear Science Advisory Committee site.
