Wikipedia:Featured article candidates/Vacuum/archive1

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[edit] Vacuum

Self-nomination It's much ado about nothing. I've done a lot of work on it for the last year or so, and I think it's ready.--Yannick 00:49, 4 May 2006 (UTC)

  • Looks really good. I have a few comments:
  • Some of the main article links are italicized, some aren't. I think they're usually italicized, so please make this consistent.
  • The see also should be trimmed of everything that is linked to elsewhere in the article.
  • More citations would be a good idea. Any number (i.e. a measurement of something, a statistic) should probably be cited.
  • I don't see why "Measurement" is in bullet-points. Each of those could be a normal paragraph.
  • "Properties" is really stubby. If you don't already know what that stuff means, it's not very helpful. Is a magnetic permeability approaching 4π×10−7 N/A2 in someway interesting? Does it change the properties of magnetism in some way?
As an outsider and a physicist, it is interesting. To take one example, the speed of light varies with permeability. Batmanand | Talk 23:30, 4 May 2006 (UTC)
That's precisely the point. The article should explain why this is interesting. Tuf-Kat 05:29, 6 May 2006 (UTC)
  • Generally, only the article in the lead and any redirects are bolded. Is there a reason there's more in this article.
See Wikipedia:Manual of Style#Legibility--Yannick 02:41, 5 May 2006 (UTC)
And also because the red link nazis keep raiding popular articles and turning links into boldface.--Yannick 05:27, 5 May 2006 (UTC)
I think most don't help legibility at all, and many are discussing a use-mention distinction, which means they should be italicized (e.g. "These ideal physical constants are often called free space constants"). See words as words.
Ah. Thank you. I was not aware of that MoS section.--Yannick 15:53, 6 May 2006 (UTC)
  • I don't think the "Examples" are needed. I don't really know anything about vacuums except what I've read here, and I don't really get anything out of them. Maybe one of each category could be added to the table of vacuum categories above it. The remainder don't seem very informative; I guess the rating of a vacuum cleaner is interesting and could be worked into a sentence earlier in the section.
As people get used to the idea that vacuum is always partial and quantifiable, they often ask what is the vacuum quality of some common devices, and how they compare to the vacuum of space. Look at the talk page archive for examples of this. It helps define a "vacuum spectrum" in people's mind.--Yannick 02:41, 5 May 2006 (UTC)
It would be more helpful to move the examples into the top table so you could see which examples go with which part of the spectrum without scrolling up and down and comparing the numbers. Tuf-Kat 05:30, 6 May 2006 (UTC)
  • Lots of passive voice, most of which could be removed.
  • I cleaned up the "Pumping" section a bit. It's not clear if lungs are a "positive displacement pump" or not. Also need a few words explaining how momentum and entrapment pumps work. Check to make sure I didn't introduce any errors in that section (I just wanted to give an idea on how the prose can be cleaned a bit) -- if I did, that's probably a sign that the original was significantly unclear.
I found at least 10 errors introduced by your edit, and I'm having trouble understanding how it makes anything clearer. Lungs are indeed a positive displacement pump. I will work on a better version, but it will take me a while.--Yannick 02:41, 5 May 2006 (UTC)
I made some improvements, found another dozen technical errors, and eventually just reverted a couple of paragraphs. The begining of this section should be clearer now, but then it trails into increasingly technical stuff meant for increasingly specialised audiences. I think this is an appropriate structure for a technical article, and the detailed layman's explanations should be left to the daughter article.--Yannick 05:25, 5 May 2006 (UTC)
Your changes have made that section much clearer, I think (though consider using the term "vacuum pump" somewhere earlier in the first paragraph). The whole article really needs a cleanup like that, though. Tuf-Kat 05:29, 6 May 2006 (UTC)
Fixed first two comments. Although I kept Suction on the list. It's a judgement call.--Yannick 02:04, 4 May 2006 (UTC)
  • Well, IMO, no article should have a "see also". If a subject is relevant, it should be covered elsewhere. There's no consensus for that view, so I won't oppose based on it, but that's my philosophy. This "see also" still seems bloated to me, and putting a red link in see also is kinda pointless. Tuf-Kat 23:12, 4 May 2006 (UTC)
  • Comment- the details in the Quality section would probably be easier to floow if they were in tables.--nixie 04:41, 5 May 2006 (UTC)


  • Object, 2a. Here are a few reasons.

'A vacuum is a volume of space that is empty of matter, relative to the atmosphere, so that gaseous pressure is much less than standard atmospheric pressure'

This is contradictory: 'empty' is a binary epithet, i.e., something's either empty or it's not; yet this is immediately treated as a comparitive ('relative to' and 'much less'). You go on to explain it in the lead; get rid of the empty bit at the start.

I'm not sure about this. Are you saying that a glass cannot be half-empty, and a gas tank cannot be almost empty?--Yannick 04:53, 6 May 2006 (UTC)
"half empty" and "almost empty" limit the adjective with a qualifier, which is fine. I think he's saying that the first bit says it is "empty of matter" with no qualifiers, and then implies that it is not "empty of matter" since it has less gaseous pressure than something else (the implication being that it has still has some gaseous pressure). Something like "space filled with less matter than the atmosphere, so that gaseous pressure is lesser than" would be better. Tuf-Kat 05:29, 6 May 2006 (UTC)

There are 'also' problems; most of the alsos should be removed—Why do we see 'also using', then 'using', and 'also used' then 'used'. Either insert 'also' in every single statement (which would be tiresome) or remove the word throughout.

'It has no friction'—awkward and stubby.

I hate 'manned spaceflight'—sexist and redundant. Use a piped link to render just 'spaceflight'.

Tony 06:24, 5 May 2006 (UTC)


  • Oppose: I'm sorry, but this article really sucks! 128.208.45.223 00:41, 6 May 2006 (UTC)
    • That's not an actionable objection. If you don't provide a fixable problem, your opinion will not be taken into account. Tuf-Kat 05:29, 6 May 2006 (UTC)

Are there any better pictures of the Crookes tube or perhaps a more striking picture? The content I'm alright with, but the aesthetics could use some work--Jonthecheet 09:10, 6 May 2006 (UTC)

  • Comment Some things I would have expected to see in this article:
    • 'Uses' section could be expanded upon, particularly historic uses.
    • Historic means of production: such as the creation of partical vacuum by condensing steam
That's a type of sorption pump, a precursor to the cryopumps that are still in use today. Was the steam condensation technique widely used in anything other than the Newcomen steam engine? My understanding is that Guericke's air pump and Geissler's mercury pump were the two most important historic means of production, both of which were positive displacement pumps. My point is, was steam really a historic means of production, or just a strange means of production?
Isambard Kingdom Brunel's Atmospheric railway created a vacuum by steam condensation, I believe. The steam condenser in a power station creates a partial vacuum by condensing steam; the resulting large pressure difference is what drives the low pressure turbine. You might consider a sentence or so on the electrical insulating properties of high vacuum; if you like, I'll see what I can put together on that. Also: vacuum packing of food and other goods. --BillC 18:22, 6 May 2006 (UTC)
    • Unless I missed it, there is no direct reference to the famous NASA incident wherein a technician ruptured his spacesuit in a vacuum chamber and passed out. --BillC 16:15, 6 May 2006 (UTC)
  • Comment. Because I lack the scientific background to assess the factual accuracy of the article, I looked at the article to see if it is comprehensible enough for the layman. I think the article is pretty understandable for educated readers. I do have the following comments:
    • You should explain that "vacua" is the plural of "vacuum." You might want to consider using the plural "vacuums," which appears to be far more common on the Internet.
    • You might want to put the word "quality" in bold when you first use it to indicate it is a "vocabulary word" rather than something the reader is expected to know already.
    • Instead of writing that vacuum "is most commonly measured in units of torr," consider writing, "units called torr." This would make it clearer what torr are.
    • I believe articles should not use Wikilinking as an excuse not to define terms in the article. Consider very short descriptions of terms not now defined. For example, instead of just writing "neutrinos," you could write "tiny particles known as neutrinos." Other terms that might merit short descriptions are: plasma, bends, gas embolism, tardigrade, Scientific Revolution, aether, interferometer, thermodynamic equilibrium, vacuum energy, cosmological constant, Casimir effect, Lamb shift, momentum transfer, dynamic pump (not linked), entrapment, ultra high vacuum, sublimation, chamber materials (not linked), rotary vane pumps, cyropump, absolute pressure, Crookes radiometer, Bourdon tube, thermocouple, and Resistance Temperature Device.
    • I don't understand the sentence about Einstein.
    • Instead of the sentence that mentions the Dirac equation, I would simply write, "Dirac's theory helped him discover the positron, the positively charged equivalent of the electron."
The positron was discovered by Carl D. Anderson, and would probably have been discovered just the same without the help of Dirac's theory. The combination of the Dirac equation with the Dirac Sea interpretation led to his correct prediction of the positron, even though the Dirac Sea interpretation was wrong.--Yannick 19:45, 7 May 2006 (UTC)
    • The paragraph about uncertainty might be made a little easier to understand.
    • The section on quantum-mechanical definition is, as you would expect for the subject matter, not comprehensible to the layman. I would recommend adding a prerequisite box template to suggest articles readers could look at to understand the subject matter.
    • It would be helpful if the diagram of the pump had a label for the "small sealed cavity."
    • One of the paragraphs in the section on outgassing begins, "Ultra-high vacuum are...." Shouldn't that be "vacua" or "vacuums?"
    • I don't know what you mean by "dessicating" or "baking." -- Mwalcoff 02:38, 7 May 2006 (UTC)