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Questioning the Law of Conservation of Energy
- corporate_shi11 7y agoI read recently that through the Casimir interaction, heat can be dissipated in a 'vacuum' as it is transferred to virtual particles. When this happens and the virtual particles pop back out of existence, do they carry the energy they absorbed along with them into nonexistence? Or by absorbing energy do they become real? Would that then mean energy is being created?
- ianai 7y agoCuation-I’m surely an idiot on cosmology and physics. Current theory is that all mass energy will eventually wind up in black holes - which will then evaporate. All mass energy will then be maximally dispersed in the entropy death of the universe. I think that means the Casimir effect is not destroying mass energy, just dispersing it to a useless state.
- deehouie 7y agosome references please
- eesmith 7y agohttps://news.ycombinator.com/item?id=21770464 https://news.ycombinator.com/item?id=21770464 was posted 20 hours ago on the topic, pointing to https://phys.org/news/2019-12-energy-space-quantum-weirdness.html https://phys.org/news/2019-12-energy-space-quantum-weirdness... .
- SideburnsOfDoom 7y agoI'm no physicist, but the article says "phonons can indeed be transferred across a vacuum by invisible quantum fluctuations." Which is not the same as "heat can be dissipated in a 'vacuum' as it is transferred to virtual particles." spot the difference: "transferred across a vacuum" (to some other object) vs. "dissipated in a vacuum" (to nowhere).
- eesmith 7y agoPerhaps physics has a specialized version of "dissipated"? A look at https://en.wikipedia.org/wiki/Dissipation https://en.wikipedia.org/wiki/Dissipation suggests that's the case. And perhaps corporate_shi11 is using "dissipated in a vacuum" to mean "transfer of internal energy from a hotter body to a colder one across a vacuum"? shrug - I dunno.
- madhadron 7y agoHeat can be dissipated in a vacuum by electromagnetic radiation. This is how most heat is dissipated in a vacuum. For the Casimir interaction, virtual particles are one way to do the bookkeeping to calculate the force between two objects. One object transfers energy and momentum to virtual particles which in turn transfer the energy and momentum to another object.
- lngnmn1 7y agoYou cannot. It is the same as questioning the actual wiring of a processor from the level of the code. Abstraction barriers are very real, immutable and impenetrable by definition.
- tobmlt 7y agoPutting aside the quantum aspects of this article for a moment, (not that they aren't fascinating, but, ...well, one can only think so hard at the end of the day!) I think this is a good place to link to Sean Carroll's post about the gravitational aspects of the general issue (for anyone who might not have seen it): https://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/ https://www.preposterousuniverse.com/blog/2010/02/22/energy-...
- 8bitsrule 7y agoEnergy is a slippery concept. To Wikipedia it's a 'quantitive property' that 'must be transferred to an object.' A property. Good luck weighing that, or nailing it to a tree. Consider the 'transformation of energy' ... from mechanical to electrical to acoustical to chemical to potential to kinetic to thermal (end of the line). What is the 'it' that's being transformed? In one sense all things are 'energetic' so long as they have a velocity (relative to something else). We need to keep an eye on boulders up on hillsides. They're not moving right now ... but their potential energy might be transferred to us, thanks to the equally mysterious 'gravity'. Yes, the math all seems to work. But we're not quite 'there' yet. Our position is uncertain.
- robomartin 7y agoIs heat really the end of the line? Heat engine to mechanical, etc.
- TeMPOraL 7y agoThat's an interesting question. AFAIU, heat engines don't take energy from heat, but from heat difference. In this sense, heat is like potential energy - an absolute value is arbitrary and meaningless in isolation, but moving mass between two points of different potential lets you store or extract energy. OTOH, from what little I remember from reaction kinetics in chemistry, temperature there is used as absolute value that determines the chance of collision between their molecules and the "activation energy", both of which influence the rate of a chemical reaction. In this space, thermal energy seems like something absolute. What gives?
- saagarjha 7y ago> In this sense, heat is like potential energy - an absolute value is arbitrary and meaningless in isolation Not quite. Potential is defined with an arbitrary basis as you’ve pointed out, but with temperature the basis is not arbitrary: it’s chosen for us, and this value is absolute zero. Taking a temperature difference is not enough to figure out how well a heat engine will work on it.
- microcolonel 7y agoAt least this one has a direct title. The other "but what if we ignore thermodynamics for a moment" articles that pass by HN sometimes bury the lede a bit.
- feoren 7y agoConsidered abandoning reading when I saw the ridiculous "if we believe in dark matter, why not aliens?" headline on the side. Did stop reading when they started talking about quantum mechanical observations. Is Nautilus just a Markov generator trained on terrible Quora answers?
- chr1 7y agoThis is not really fair. The "why not aliens" article is an interview with a scientist who argues that we should not outright dismiss the possibility that something (particularly omuamua comet) is alien technology, until we have proof one way or the other, which is not a ridiculous thing to say. I also can't see what is particularly wrong with the description of quantum mechanical observations in this article. It looks to me like a good enough description of the idea of research done by the author himself.
- afthonos 7y agoMe: “Questioning the media’s elite-driven narrative” is such a clickbait headline. Also me: “Questioning the law of conservation of energy”—aaah, a headline clearly intended for sophisticates like myself. (The article itself is good; I’m just amused at my own reaction.)