Mondo Knows Facts
Carnot set a limit on engine efficiency
No heat engine can beat one minus the ratio of cold to hot temperatures Sadi Carnot showed in 1824 that the best possible efficiency depends only on the absolute temperatures of the hot and cold reservoirs. An engine running between 600 and 300 kelvin could never exceed 50 percent, whatever its design. Real engines fall short because of friction and heat losses. 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
Heat moves in three distinct waysConduction passes energy through contact, convection carries it in fluids, radiation needs no mediumAbsolute zero is the theoretical lower limit of temperatureAt minus 273 degrees Celsius all classical thermal motion of atoms stops completelyWater exists as solid liquid and gas at its triple pointAt zero point zero one degrees Celsius and specific pressure water coexists in three statesEnergy cannot be created or destroyed only transformedThe total energy in an isolated system remains completely constant over timeEntropy measures how spread out energy isThe second law says isolated systems grow more disordered over timeChemical reactions either release or absorb thermal energyExothermic changes release heat while endothermic processes absorb energy from surroundings
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Tags: physics, thermodynamics, engines
Carnot set a limit on engine efficiency: the short answers
- Where does this come from, and can I check it?
- No heat engine can beat one minus the ratio of cold to hot temperatures. The figure is taken from Encyclopaedia Britannica, 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.