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"Due to mass–energy equivalence, any object that has mass when stationary (called rest mass) also has an equivalent amount of energy whose form is called rest energy, and any additional energy (of any form) acquired by the object above that rest energy will increase the object's total mass just as it increases its total energy."
Will a space ship increase in mass if it gains potential energy when raised from one circular orbit to a higher, slower circular orbit?Darsie42 (talk)22:53, 6 April 2022 (UTC)[reply]
Most likely not! Its increased potential energy will be achieved by converting energy of some other form, so the total energy of the space ship might remain the same.Dolphin(t)01:20, 7 April 2022 (UTC)[reply]
I believe that the energy would be considered to be stored in the gravitational field itself. In general relativity, spacetime has self-interaction. For example, it is possible to create a black hole from gravitational waves alone; the black hole would have mass and thus energy. However, I'm not sure if people really talk about it, since energy in GR is not well defined. I'm speaking as a layman on the topic so take what I say with a grain of salt.BirdValiant (talk)01:32, 7 April 2022 (UTC)[reply]
Entropy is one of two components of free energy, a key idea of chemical energy, and is also related to several aspects of thermal energy. It also relates to multiple aspects of thermocdynamics in general (see several previous talkpage discussions).DMacks (talk)04:26, 12 August 2024 (UTC)[reply]
I think your argument is flawed:
1.What, in classical or new physics is "free energy"? Justifying the presence of Entropy on the Energy page on that basis is very poor logic.
2. There are at least two independent interpretations of entropy: one from the subjective identification of the number of micro-states in a macro-state (whatever they are!), and one from the thermodynamics of an irreversible process. Neither can be deduced from the other.
What? Entropy having a distinct sense in statistical mechanics doesn't negate the relevance of using the word for its sense in thermodynamics. It is perfectly justified to include summary discussions of related subjects in this way, as they are often needed for a holistic understanding of a topic.
Supporting a challenge to a Wiki article by quoting another Wiki article is nonsense. Energy is a clearly identified physical property. Entropy is not.
You asked what something was, and the article is about what it is. That's just me trying to answer the very basic question you asked, regardless of what it supports.
In science, you can't have two independent properties with the same name!
Wikipedia is a general encyclopedia, not whatever restrictive genre you're speaking about where every word has exactly one meaning.Remsense ‥ 诉03:01, 18 August 2024 (UTC)[reply]
I think you may be channelling Humpty Dumpty in Through the Looking Glass :
"When I use a word," Humpty Dumpty said, in rather a scornful tone, "it means just what I choose it to mean — neither more nor less."
The language of science is indeed " a restrictive genre ... where every word has exactly one meaning."
Au contraire—as it pertains to site policy, we use words the way sources use them, so please keep that in mind before any further edits based on your very particular perspective on how language must be be used.Remsense ‥ 诉04:45, 18 August 2024 (UTC)[reply]
And there's my problem. "Sources" use entropy in two totally incompatible senses. That tautology should be argued out in an Entropy forum, not here. We should be smart enough to see the elephant in the room and avoid references to such a challenged concept.Gpsanimator (talk)06:16, 18 August 2024 (UTC)[reply]
They are not incompatible, but merely logically independent. It is obvious to most people which sense is meant with a bit of context. To be clear, if you want to make a case for removing this material, you need to cite people who are saying it's a problem or that entropy is not an important concept for a generalized understanding of energy. Can you point to anyone in the literature who has these same worries about use of the word "entropy", or is this your own deduction?Remsense ‥ 诉06:19, 18 August 2024 (UTC)[reply]
"Can you point to anyone in the literature who has these same worries about use of the word "entropy? Not many, but those who do are worth listening to Check Sabine Hossenfelder YT (can't post the link)
Incompatible? yeah: find anyone who can rationalise micro- and macro-states with thermodynamic energy balance!
Unfortunately, this seems to be your personal hang-up unless you can cite anyreliable sources that corroborate that this is actually a problem, since we don't write articles based on our personal favorite interpretations.Remsense ‥ 诉07:00, 18 August 2024 (UTC)[reply]
Jus for fun, decided to check how long does it take for Wiki to correct a mistake.
The sentence in the article contains a mistake in Joule calculation which must be 6.9 MJ = 80 *24*3600!...using as a standard an average human energy expenditure of 6.9 kJ per day and a basal metabolic rate of 80 watts.141.168.147.196 (talk)09:24, 14 January 2025 (UTC)[reply]
The table of the forms of energy listsNuclear binding energy andRest energy as two different kinds of energy. Since both arise from the same formula (mass multiplied by the speed of light in vacuum), are they really two different forms of energy, or the same form? I'm not a physicist, just an honest doubt.Siaraman (talk)12:26, 27 February 2025 (UTC)[reply]
The rest energy is the energy that a mass would become if entirely converted into energy. It is not a type of energy but a measure of the energy that would be released. The nuclear binding energy is the amount of energy needed to pull an atom apart into its neutrons and protons. It too is not a type of energy but a measure of energy that would need to be used.StarryGrandma (talk)16:07, 27 February 2025 (UTC)[reply]
To expand, type of energy is a non-specific term. The table explains that rest mass energy is potential energy. Binding energy isn't potential energy; it is the energy that was released when the atom was formed and would have to be put back to take it apart.StarryGrandma (talk)16:23, 27 February 2025 (UTC)[reply]
This text is technically in error."The SI unit of power, defined as energy per unit of time, is the watt, which is a joule per second. Thus, one joule is one watt-second, and 3600 joules equal one watt-hour."
One Joule does not equal a watt-second. 1 watt = 1 joule in 1 second The phrasing is exactly backward. This is highly important in the concept of the difference between "power" measured in Watts and "energy" measured in Joules. A Joule, as a measure of energy by definition, does not have a time component. A Watt by definition as a measure of power "must" have a time component. By the same token, 3600 joules does not equal a watt-hour. Correctly phrased, it should be "A watt-hour is one Joule per second for 3600 seconds. An example where a watt-second is used in expressing power is for example a camera flash. This is an industry specific use which does NOT apply to general electrical usage. It should not be used in describing electrical power because a Watt by definition is literally 1 Joule for 1 second.
I will leave this up for a week or two and if no objections will edit the main page with appropriate changes. I don't want to make changes without review!
Here is my proposed revised text:"The SI unit of power, defined as energy per unit of time, is the watt, which is one joule in one second. Thus, one Joule of energy consumed in one second is one Watt, 3600 joules of energy consumed in one hour is one watt-hour, and 3.6 million Joules consumed in one hour is one kilo-watt hour (kWh). In defining the difference between "energy" and "power", the key understanding is that power always contains a measure of time whether second, hour, day, year, or other time measure. Energy by definition does not contain a measure of time. SI units are set up to make conversion of Watts to Joules simple such that 1 kilo-Watt hour (kWH) implies 3.6 million Joules of energy being consumed in one hour. One kWh is a measure of Power while 3.6 million Joules is the amount of energy expressed in that kWh"