Thomas Edison on his 77th birthday in his laboratory.
When Thomas Edison hired new employees, he presented them with a 150-question quiz, containing different questions depending on the position. But often, the questions had nothing to do with the job; Edison just wanted to know how educated the applicant was. And sometimes there were other reasons behind the interrogation…
Who discovered the X-ray?
The obvious answer to this question is Wilhelm Röntgen, who, in 1895, famously noted the effects of a mysterious new kind of ray that appeared as a byproduct of his experiments with Crookes tubes. He called his discovery the “X ray,” to indicate its yet unknown properties, then went on to take a widely publicized X-ray print of the bones of his wife’s hand, and eventually won a Nobel prize in 1901 for his achievements. However, several other physicists made similar discoveries while experimenting with Crookes tubes around the same time. Among them: Nikola Tesla, Edison’s well-known rival. Edison had himself experimented with X-rays for a time, and was certainly aware of the variations in the X-ray origin story among his colleagues. This question suggests an eagerness to promote his preferred version.
Think you could pass his test? See a selection of the questions (and the answers) at mental_floss. Link