dorsal/arxiv
View SchemaThe solar sail and the mirror
| Authors | Thomas Gold |
|---|---|
| Categories | |
| ArXiv ID | physics/0306050 |
| URL | https://arxiv.org/abs/physics/0306050 |
Abstract
The radiation pressure exerted by incoherent light on diverse surfaces is examined. The thermodynamic rule, first given by Carnot in 1824, describes the limitation to the amount of free energy that can be obtained from a source of thermal energy, and he gave the compelling reason for this rule, that if more free energy than he had prescribed could ever be extracted, then a heat pump could use that free energy and re-create all the heat energy that had been consumed. A perpetual motion machine could then be constructed. Now, 179 years later, it is proposed to fly a spacecraft that is expected to gain velocity from the radiation pressure the sunlight is expected to exert on solar sails, panels of thin plastic sheets, mirror surfaced on the side facing the sun. However a detailed examination of this proposal shows it to be in direct conflict with Carnot's rule, and no such pressure can be expected. Either Carnot's accepted rule is in error, or the solar sail proposal will not work at all.
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"abstract": "The radiation pressure exerted by incoherent light on diverse surfaces is\nexamined. The thermodynamic rule, first given by Carnot in 1824, describes the\nlimitation to the amount of free energy that can be obtained from a source of\nthermal energy, and he gave the compelling reason for this rule, that if more\nfree energy than he had prescribed could ever be extracted, then a heat pump\ncould use that free energy and re-create all the heat energy that had been\nconsumed. A perpetual motion machine could then be constructed. Now, 179 years\nlater, it is proposed to fly a spacecraft that is expected to gain velocity\nfrom the radiation pressure the sunlight is expected to exert on solar sails,\npanels of thin plastic sheets, mirror surfaced on the side facing the sun.\nHowever a detailed examination of this proposal shows it to be in direct\nconflict with Carnot\u0027s rule, and no such pressure can be expected. Either\nCarnot\u0027s accepted rule is in error, or the solar sail proposal will not work at\nall.",
"arxiv_id": "physics/0306050",
"authors": [
"Thomas Gold"
],
"categories": [
"physics.space-ph",
"physics.optics"
],
"title": "The solar sail and the mirror",
"url": "https://arxiv.org/abs/physics/0306050"
},
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