Where does this come from, and can I check it?

A thermometer placed past the red light of a spectrum recorded the most heat. The figure is taken from Royal Society, 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.

Mondo Knows Facts

Herschel found infrared beyond the red end

A thermometer placed past the red light of a spectrum recorded the most heat In 1800 William Herschel split sunlight with a prism and measured the temperature at each colour. The reading kept climbing as he moved the thermometer beyond red, into a region where nothing was visible. He concluded that an invisible form of light carried the heat, which we now call infrared. It sits in Mondo's science collection, one of 200 facts that each trace back to the reference below.

Where this comes from

Royal Society

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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Newton split white light with a prismA glass prism spreads sunlight into a rainbow because each colour bends differently The photoelectric effect needs a minimum frequencyWeak blue light ejects electrons from a metal that intense red light cannot touch Fluorescent things glow only while litFluorescent materials absorb short wavelengths and re-emit them almost at once Light travels at nearly three hundred million metres per secondIn a vacuum light travels at an exact speed of 299,792,458 metres per second Particles moving faster than light in water glow bright blueCherenkov radiation acts as an optical sonic boom for high speed charged particles Bioluminescence generates light without losing energy to heatEnzymatic oxidation of luciferin produces efficient cold light in living organisms

Tags: light, infrared, history

Herschel found infrared beyond the red end: the short answers

Where does this come from, and can I check it?: A thermometer placed past the red light of a spectrum recorded the most heat. The figure is taken from Royal Society, 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.