Answer: Taking an X-ray
This photo depicts an early technology that would eventually be incorporated into X-ray technology. These two men are using something called the Crookes tube to take an X-ray image of the seated man’s hand. Physicist William Crookes discovered how to use this technology to take see-through images of the human body. Naturally, it was a pretty big deal. We wouldn’t have modern-day X-ray technology without Crookes’ experiments.
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