Mondo Knows Facts
Roentgen discovered X-rays by accident
A glowing screen in a darkened lab revealed radiation that passed through his hand In 1895 Wilhelm Roentgen noticed that a screen coated with barium platinocyanide glowed while a covered cathode ray tube was running. The rays escaped the tube, darkened photographic plates and passed through soft tissue. He called them X-rays and received the first Nobel Prize in Physics in 1901. It sits in Mondo's science collection, one of 200 facts that each trace back to the reference below.
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Facts that can change over time are reviewed and updated. If something here looks wrong, Mondo would rather know than be confidently incorrect.
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More facts like this
Planck quantised energy to fix a spectrumThe 1900 formula matched glowing object colours by assuming energy comes in chunksBohr put electrons into fixed shellsThe 1913 model explained the sharp lines seen in the hydrogen spectrumKepler replaced circles with ellipsesPlanetary orbits are ellipses with the Sun at one focus, not perfect circlesThe photoelectric effect needs a minimum frequencyWeak blue light ejects electrons from a metal that intense red light cannot touchHeat and temperature are not the same thingTemperature is average particle energy, while heat is energy on the moveEntropy measures how spread out energy isThe second law says isolated systems grow more disordered over time
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Tags: physics, x-rays, history
Roentgen discovered X-rays by accident: the short answers
- Where does this come from, and can I check it?
- A glowing screen in a darkened lab revealed radiation that passed through his hand. The figure is taken from Nobel Prize, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
- Is this really a science fact?
- Yes. It sits on the Science shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
- What else can I read about it?
- The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.