Talk:Quasistatic process

Last paragraph - no such thing?
What on Earth does the last paragraph mean? It seems to completely contradict the first. If the example at the start is wrong, why was it left in the article? I'm really confused. 84.12.252.210 14:13, 10 July 2007 (UTC)

Example?
If the processes are typically reversible, shouldn´t the article give an example of one of them (since there should be numerous of these processes)? —Preceding unsigned comment added by 190.189.34.113 (talk) 04:57, 8 October 2009 (UTC)

Infinitesimal cycles?
Now what on earth, dare I ask, is a series of infinitesimal cycles of equal intervals?--Marc Goossens (talk) 18:37, 21 November 2009 (UTC)

Near equilibrium or not?
In the lede:

''In thermodynamics, a quasistatic process is a thermodynamic process that happens "infinitely slowly". No real process is quasistatic, but such processes can be approximated by performing them very slowly.''

But later:

A notable example of a process that is not even quasistatic is the slow heat exchange between two bodies at two finitely different temperatures, where the heat exchange rate is controlled by an approximately adiabatic partition between the two bodies &mdash; in this case, no matter how slowly the process takes place, the states of the two bodies are never infinitesimally close to equilibrium, since thermal equilibrium requires that the two bodies be at the same temperature.

It seems that a new condition, being close to equilibrium, has been snuck in. What gives? Must a quasistatic process be close to equilibrium at each moment, or not? 89.217.19.174 (talk) 19:39, 4 February 2015 (UTC)

Contradiction
The article says that "No real process is quasistatic ..." and then immediately says that "Any reversible process is necessarily a quasistatic one", which introduces a contradiction because there are, in fact, real processes which are reversible. This implies that there are real processes which are quasistatic. I haven't even taken my quals yet and I know that something is fishy here. — Preceding unsigned comment added by 2601:840:8300:f81f:603e:4b41:3bd:21da (talk • contribs) 23:07, 22 July 2015‎
 * No real processes are reversible. At least not on the macroscopic level. — Preceding unsigned comment added by 184.66.32.152 (talk) 08:06, 9 February 2018 (UTC)

Outside of thermodynamics
This page is linked to from inertial number. Perhaps it should say something about quasistatic processes outside of the context of thermodynamics? For example, Stokes flows are sometimes described as quasistatic (see e.g. --jftsang 14:08, 23 September 2015 (UTC)

Constant pressure during quasi-static compression?
The 2nd sentence of the article states:

"An example of this is quasi-static compression, where the volume of a system changes at a rate slow enough to allow the pressure to remain uniform and constant throughout the system."

It seems to me that during compression the pressure will not be constant, unless energy is removed from the system as heat. Should the words "and constant" be removed from the statement above? — Preceding unsigned comment added by David Boyd Hansen (talk • contribs) 16:29, 13 June 2017 (UTC)

I think the misunderstanding is the following: the text means that the pressure is constant throughout the system, spatially, that is, it cannot be the case of the system having one part with a higher pressure than another part, while you seem to have understood that the pressure is the same along different instants of time, what really does not seem to be the case. But, although the statement is correct in my opinion, it can really lead to such misunderstandings and maybe it would be better to remove "constant" and let just "uniform". Other suggestions of alteration of the sentence to avoid this misunderstanding are welcome. Kelvynwelsch (talk) 06:51, 11 May 2021 (UTC)

spelling of 'quasistatic'
There are two customary spellings for 'quasi(-)static', namely 'quasi-static' and 'quasistatic'. The present title of the article has chosen 'quasistatic' while the body of the article chooses 'quasi-static'.

Some reliable sources are

quasistatic

Adkins 3rd edition (1983), Blundell (2006), Landsberg (1971), Moran 9th edition (2018), Pippard (1966), Schroeder (2000), Silbey (2005), ter Haar (1966), Tisza (1966), Tschoegl (2000),

quasi-static

Anderson 2nd edition (2005), Attard (2002), Buchdahl (1966), Callen 2nd edition (1985), Çengel 8th edition (2015), Giles (1964), Kestin (1971), Landau 3rd edition (1980), Rajput 4th edition (2010), Reif (1965), Tisza (1966), Wilson (1957)

text does not use

Atkins 8th edition (2006), Baierlein (1999), Borgnakke 7th edition (2009), Bridgman (1943), Denbigh 4th edition (1981), Grandy (2008), Guggenheim 5th edition (1967), Kittel (1980), Maxwell 11th edition (1899), Partington (1913), (1949), Perry 8th edition (2008), Planck (1903), Prigogine (1954), Reynolds 2nd edition (1971), Ruelle 2nd edition (2004)

At present I do not feel an urge to meddle with the present mixture of spellings in the article.Chjoaygame (talk) 15:40, 26 August 2019 (UTC)

The Oxford English Dictionary does not list 'quasi(-)static', but offers many words as spelt 'quasi-xxx', for example 'quasi-equilibrium'.Chjoaygame (talk) 16:15, 26 August 2019 (UTC)

meaning of 'quasi'
The Oxford English Dictionary gives several meanings of the English word 'quasi': 'as if', 'as it were', 'almost', 'virtually'; when hyphenated: "kind of, resembling or simulating, but not really the same as, that properly so called'".

The English word comes from the Latin word 'quasi' that, by Lewis & Short, is primarily literally translated as 'as if', but also is translated as 'as it were'; secondary meanings are given as 'about', 'nearly', 'almost'. and 'partly'.

In the present context, I prefer 'as if', and I have edited accordingly.Chjoaygame (talk) 16:15, 26 August 2019 (UTC)

quasi-equilibrium
The term 'quasi-equilibrium' or 'quasiequilibrium' is also used. For example, by

Borgnakke 7th edition (2009) (quasi-equilibrium), pages 16, 17, 63, 93, 94, 95, 97, 98, 101, 102, 103, 104, 105, 122, 125, 141, 142, 143, 146, 171, 249, 251, 292, 672.

Bridgman (1943) (quasi-equilibrium), page 185.

Çengel 8th edition (2015) (quasi-equilibrium), pages 16, 40, 42, 123, 164, 165, 166, 167, 169, 171, 172, 182, 195, 196, 197, 203, 281, 292, 295, 296, 311, 316, 340, 348, 359, 776, 795, 806.

Moran 9th edition (2018) (quasiequilibrium), pages 31, 32, 33, 35, 36, 59, 77, 78, 100, 156.

but not by

Adkins 3d edition (1983), Anderson 2nd edition (2005), Atkins 8th edition (2006), Buchdahl (1966), Callen 2nd edition (1985), Denbigh 4th edition (1981), Giles (1964) Grandy (2008), Guggenheim 5th edition (1967), Kestin (1971), Landsberg (1971), Maxwell 11th edition (1899), Partington ((1913), (1949), Pippard (1966), Planck (1903), Prigogine (1954), Rajput 4th edition (2010), Reif (1965), Reynolds 2nd edition (1971), Ruelle 2nd edition (2004), Schroeder (2000), Silbey (2005), ter Haar (1966), Tisza (1966), Tschoegl (2000).

Chjoaygame (talk) 17:33, 27 August 2019 (UTC)