Talk:Vacuum

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Former featured article candidate Vacuum is a former featured article candidate. Please view the links under Article milestones below to see why the nomination failed. For older candidates, please check the archive.
Article milestones
Date Process Result
April 25, 2006 Peer review Reviewed
May 7, 2006 Featured article candidate Not promoted
Current status: Former featured article candidate
edit·history·watch·refresh Stock post message.svg To-do list for Vacuum:
  • Review section on Effects on Humans
  • Review new rewritten Vacuum pumping and Outgassing sections
  • check copyright status of pictures
  • Expand Uses section, mention aspirators and house vacuum, and mention vacuum lines and manifolds, cold traps, uses in chemistry, filtration, distillation, medical facilities, transfer of gases, use of ejectors in condensers (add a graduated scale 1Atm-0 showing the relative pressure of typical applications: house vacuum, what a human can pull (~10' of water), TV CRT, ...).
  • Clarify "temperature" of outer space (See archive)
  • Stop spreading misinformation about the Michelson-Morley experiment.
Priority 1 (top)
Archive
Archives
  1. May 2003 – April 2006
  2. April 2006 - December 2008
  3. January 2009 - February 2012

Catholic Church and the vacuum[edit]

In the text it says the following

In medieval Europe, the Catholic Church regarded the idea of a vacuum as against nature or even heretical; the absence of anything implied the absence of God, and harkened back to the void prior to the creation story in the Book of Genesis.

As a source it lists Edward Grant (1981), but does not list a page. However, when I checked pages 108–109 of said source, it points out that, after 1277, Christian scholars came to believe that "God could create or allow a vacuum beyond the world". Reading further, it appears that what the church found abhorrent was the idea of a pre-creation void, rather than the existence of a vacuum itself. I.e. their qualm was with a void that existed without a God; not with the idea that a void implied that God didn't exist. I know it's a nuance of interpretation, but the current wording in the article just makes the scholars of the time seem completely ignorant. Regards, RJH (talk) 15:11, 24 March 2012 (UTC)

The void beyond the world would become an attractive location for Heaven in syncretic accord with the unused real-estate in Aristotelian cosmology (never mere vacuum). FWIW, note that it says against nature or even heretical… If it can't be verified, perhaps it should be clipped at the semicolon?—Machine Elf 1735 15:31, 24 March 2012 (UTC)

6.1 Relative versus absolute measurement[edit]

Should this just be tossed?? (see gauge pressure under "pressure measurement)

Vacuum is measured in absolute terms with the "highest vacuum pressure" = 1 atm BY DEFINITION. On Jupiter, a new definition of atm pressure could be used. Any pressure below the defined "atm" on Jupiter might be considered a vacuum. This is not the same as "relative versus absolute" which is normally associated with systems where vacuum is measured as a negative pressure (relative to atm or "gauge pressure" see pressure measurement).

Bubsir (talk) 04:01, 24 July 2013 (UTC)

I agree. This unsourced section was already bad when this 2010 edit expanded it to two sections. There may be something to it, but as written it doesn't make a lot of sense. Can you find some sources and rework it appropriately? Dicklyon (talk) 05:17, 24 July 2013 (UTC)

Casimir effect?[edit]

Hi All, I just removed a poorly phrased reference to the Casimir effect in the quantum mechanics section. Although it is indeed often described as related to vacuum energy etc., there are also other ideas such as relativistic van der Waals forces. I am by no means an export on this, so perhaps someone can shed light on whtehter it's ipmortant to refer to the Casimir effiect here. At least it should then be properly phrased including caveats.WijzeWillem (talk) 09:42, 15 January 2014 (UTC)

Temperature of Perfect Vacuum[edit]

What is the temperature of a perfect vacuum? I assume it would be zero. 70.247.161.12 (talk) 02:35, 31 March 2014 (UTC)

Per wp:talk page guidelines, please see wp:reference desk/Science - DVdm (talk) 09:10, 31 March 2014 (UTC)

Add "Water Aspirator" or "Aspirator Pump" to table?[edit]

At one time, water aspirators were quite common so people have a "feel" for how strong the vacuum is. Can someone add that to the table on the main page? It can be debated, but I'd put the useful working range at from 50 torr down to around 15 torr or even 12 torr (vapor pressure of cold tap water in the winter).

Come to think of it, there is no mention of water aspirator anywhere in the main article. Add a cross-reference someplace? AdderUser (talk) 11:18, 5 June 2014 (UTC)

This article here appears to be about the "low pressure" sense of the term "vacuum" rather than the devices for accomplishing it. We have a whole separate article on vacuum pumps, that does mention aspirators. I added a more visible link to that article rather than trying to cherry-pick examples of who might recognize which of them from different eras/genres. DMacks (talk) 14:40, 5 June 2014 (UTC)

Historical Interpretation[edit]

This statement seems to leap out of nowhere, and not be related to the surrounding paragraphs:

  • The explanation of a clepsydra or water clock was a popular topic in the Middle Ages. Although a simple wine skin sufficed to demonstrate a partial vacuum, in principle, more advanced suction pumps had been developed in Roman Pompeii.

What does the explanation of a clepsydra have to do with defining a vacuum? Following the link to the water clock article fails to answer this question -- the word vacuum does not appear anywhere in that otherwise interesting article. Nor does the term wine skin. Nor does the article say anything whatsoever about any kind of "suction pumps" being in any way connected with water clocks.

Either this statement requires more detail, explaining what the water clock has to do with the historical interpretation of "vacuum", or a better, more explanatory link needs to be provided, or else the statement needs to be removed from the article. As it stands now, it appears to be a non sequitur. — Preceding unsigned comment added by 74.95.43.249 (talk) 20:36, 30 September 2014 (UTC)

Definition[edit]

In engineering and applied physics vacuum refers to any pressure lower than atmospheric. I just added a sentence about this in the lead, but would propose to also change the first sentence to something like "Vacuum can refer to space completely devoid of mater or space with a pressure lower than atmospheric pressure.". I argue that the engineering definition is the most important one since this is the field where vacuum is used the most. I think that all books about vacuum use the low pressure definition, and I'm sure all books I have read does. Ulflund (talk) 03:55, 14 January 2015 (UTC)

Vandalism[edit]

In the first paragraph there is an appropriate statement referring to the arse of a Mr. Phil England. This needs to be removed.

Reverted, thanks. Materialscientist (talk) 02:46, 13 April 2015 (UTC)

Low Earth orbit[edit]

" Most artificial satellites operate in this region called low Earth orbit and must fire their engines every few days to maintain orbit." I find this sentence to be dubious and think it should be removed. Asgrrr (talk) 16:03, 12 June 2016 (UTC)

Perhaps a proper source can be found with Google Scholar or Google Books, or through our articles Orbital decay or Orbital station-keeping. - DVdm (talk) 16:46, 12 June 2016 (UTC)

QFT Vacuum[edit]

The vacuum from quantum field theory is a very distinct concept from the gas vacuums discussed in the rest of the article. Obviously they are related by the idea of absence of matter, but the "quantum mechanics" section leans much too heavily on the fact that they share the same name without actually explaining how they differ. Jess (talk) 12:35, 2 July 2016 (UTC)

Priority of SI units[edit]

How is Torr still the first column of the tables? SI units should be used as a priority. 130.83.66.46 (talk) 09:47, 14 February 2017 (UTC)

Article is going in two different directions[edit]

This article is clearly going it two different directions, one for the practical considerations of a partial vacuum, and one for the theoretical concerns of a pure vacuum. The article sucks because it's so conflicted. I added a split tag, because I thought it would be taken seriously, but it's been undone with no discussion, so so much for trying to offer constructive input.

It couldn't possibly be split into two articles, both titled vacuum, with a disambiguation page? No other constructive ideas? Just revert and forget I brought the idea up? Whatever. Why bother? Let's all take a good hard look at our navels. I'll be going now. 47.32.217.164 (talk) 03:26, 22 May 2017 (UTC)

I strongly thought the way you where headed was the wrong way and tried to motivate that in my revert edit summary, but I agree I should have brought it up here instead. Here is a more thorough explanation of my thinking. The most widely used meaning of the word vacuum is the same as partial vacuum, i.e. any volume with pressure lower than atmospheric, and that is the meaning intended throughout the vast majority of this article. If the article should be split into one article about perfect vacuum and one about partial vacuum, that would essentially be writing a new article about perfect vacuum and keeping the current one for partial vacuum. Some of the history and the section on classical field theories could be moved, but that is all I think is about perfect vacuum. Ulflund (talk) 05:56, 22 May 2017 (UTC)
Please think about why you "strongly thought" what you did. I want to encourage more editors to act in good faith. I might not have even mentioned it, but you specifically said "strongly", which seems disproportionate to me.
I agree that the partial vacuum is what most readers expect as a primary topic for an article called vacuum, and I like your words about "volume with pressure below atmospheric". That's very concise and accurate, and I hope something similar could be used for the lead. It also seems natural to have an article called vacuum (particle physics) or similar for the perfect vacuum. The two topics are closely related, and would share history to a considerable extent.
My feeling is that there is enough material here for two separate articles, with just a split. The biggest problem with a split in my mind would be the need to clarify which concept is being discussed. I feel a disambiguation page or hatnotes might be justifiable to help with that. 47.32.217.164 (talk) 21:07, 22 May 2017 (UTC)

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