Talk:Soap bubble

Untitled
he 'thin film' colouring phenomenon is called Newton's colours, I'm not sure about the history of it, link should be integrated into the paragraph, I tried but my writting didn't look good enough. I think Newton studied it first (hence the name ;), personally I don't know much about it, I rather read about simulations of the graphic effect.

Para 1 rewrite
Made some changes to the first paragraph. Kernel geek (talk) 08:44, 7 August 2010 (UTC)

Made some grammar changes
Kernel geek (talk) 11:00, 12 January 2009 (UTC)kernel_geek

Suggestions for improvements
"... I was told today that soap bubbles are permeable to carbon dioxide but not to air. Does anybody in this community know why/if this is so?"

Actually, my experience in this matter is a bit different. The air in a soap bubble does escape the bubble through the film and therefore, the bubble begins decreasing in size as soon as it is completed. If it were to "live" long enough, it would shrink back down to a small pool of liquid. The rate is so slow that it isn't readily noticable during the "life" of a normal bubble but if you keep it in a jar you might well notice this changing size. I saw 200 day old bubbles blown by a man (Eiffel G. Plasterer) and kept in that way. He told me that his oldest was 340 days old (it never popped, it shrunk down to liquid ... he told me that he once used a microscope to watch one continuing down within the liquid).

But, there is a difference with carbon dioxide which permeates the film so readily that it will readily diffuse INTO the bubble against the flow of air being pushed out by the internal pressure. I have filled a bathtub with carbon dioxide gas (I put dry ice in the tub and allowed it sublime off into the invisible gas without adding water to produce the familiar "fog" effect so loved by horror movie directors) and then blew bubbles which floated on the gas. But after a bit, the bubble slowly descends into the gas and can be seen to grow in size!

If you then try to lift the bubble out with the bubble wand, you'll readily see that it has become heavy with the gas and becomes difficult to lift (it droops into a drop shape).

I have one further to actually watch the invisible gas entering the bubble. This takes a bit of explaining:

I blew a grapefruit sized bubble and then blew a plum-sized smoke-filled bubble that was connected to it at the bottom. Waiting a bit to allow the spinning air inside to calm down, I then broke the wall that kept these two bubbles apart (I'm an entertainer who does a performance with soap bubbles ... I used a wet straw to go inside of the bubble and, touching the wall that separated the two, I sucked a bit thereby popping that wall without destroying the two bubbles but causing them to merge into a single larger bubble).

The smoke hangs low in the bottom of this new larger bubble. But when I put that bubble into the carbon dioxide gas, I was able to watch the gas enter the bubble creating clear lanes of air within the dense smoke. This eventually stirs up the smoke and it mixes more evenly throughout the bubble.

So, the film is permeable to both the air and to the carbon dioxide but one more readily reacts in that way.

I have written a book on soap bubbles that is now out of print and I perform regularly at science centers, universities, and elementary schools (as well as my regular nightclub and other show-biz gigs). Explaining the physics in a way that is accessible to people without a science background is not a simple matter. This article is wonderful.

Tom Noddy www.tomnoddy.com

The roof of the National Aquatic Centre in Beijing being built for the 2008 Olympics has three-dimensional strucure designed after soap bubbles. You can see images at http://www.arcspace.com/architects/ptw/. It looks very cool -- and should be an efficient way to bear the loads of the roof.

Phil Earnhardt

Two potential problems
I think there are two errors in the article, but I don't want to change an article that's already been vetted for featured-article status without discussion.
 * Water droplets are drop-shaped because of air resistance (drag), not gravity. In free fall in a vacuum they would be spherical, whereas moving through air in the absence of gravity they would be drop-shaped. The same would be true for soap bubbles, except of course those wouldn't exist if there were no air. That they are almost spherical is due to the much lower terminal velocity at which they travel through the air, compared to water droplets. This of course has to do with their weight, but air resistance is the primary cause for the drop shape; gravity is only a secondary cause, being one way to set things in motion through air.
 * The article says that the interference comes about because the internally reflected ray travels longer. This explains only the changes in interference due to thickness; the "baseline" for these changes, the complete cancellation in the limit of vanishing thickness, is due to a 180&deg; phase jump in the outer reflection.

Fpahl 00:26, 22 Sep 2004 (UTC)


 * You are completely right and should just be bold and edit the article. To be honest I'd forgotton about the phase shift when n1 < n2. I'll tell you what - you fix the article and i'll fix the diagrams. Theresa Knott (taketh no rest) 13:18, 22 Sep 2004 (UTC)
 * Now that's what I call division of labour :-). I'll do that. Fpahl 10:40, 23 Sep 2004 (UTC)
 * OK, I've done the gravity bit. I'll do the reflection bit tomorrow. I don't think the images need any changing, actually, since they only show phase relations for finite path length differences. The captions do, but I can do that together with the text. Speaking of the images, there's a little red squiggle underneath one of the '1's in the upper diagram. And I don't understand the meaning of the white and green circle connected by a line in the lower one. Fpahl 14:23, 25 Sep 2004 (UTC)
 * I've now changed the bit about interference. There was a further problem with it: The cancellation is due not just to two reflections, but to a whole series of them. I've tried to explain this without going into mathematical details. The image captions are now completely out of tune with the text, but I haven't changed them yet since Theresa is deciding whether to change the diagrams themselves. Fpahl 12:48, 1 Oct 2004 (UTC)
 * I'd suggest deleting them until they are fixed. They're confusing at the moment. Filiocht 12:55, 1 Oct 2004 (UTC)
 * I will definately amend the images this weekend come hell or high water. The problems you describe false articfacts created when I bodged the drawing :-( they will be easy to remove. Theresa Knott (The torn steak) 13:02, 1 Oct 2004 (UTC)


 * I finally fixed the two images. (you may need to refresh your cache in order to see it) I'm working on two more, one to show the phase relationships, one to show an infinite number of reflections.Theresa Knott (The torn steak) 20:00, 5 Oct 2004 (UTC)

Right here is the first diagram. I've ignored refraction effects to concentrate on the phases of the two reflected rays. I've also ignored all other reflections etc and only concentrated on the two we are actually interested in. Thoughts anyone?


 * Can you do them so that the sine waves are at zero amplitude at the reflection points? It might be a little clearer what's happening.
 * &mdash;wwoods 04:03, 6 Oct 2004 (UTC)





I fixed some typos and other small problems in the captions above. I'm in two minds about this use of only two rays. On the one hand, this might make it easier to understand the basic idea. On the other hand, it's really misleading. At shallow incidence, when the reflectivity is high, the second reflection is very insignificant compared to the first, and it's only the long train of later reflections that cancels the first. The images create the false impression that the second ray has the same amplitude as the first. Also, in the left-hand case, where the second reflection is in phase with the first, due to a path-length difference of 180&deg;, the subsequent reflections alternate in phase. I'm aware that all this is very hard to explain in an image, but I don't want people to take away an oversimplified impression of there being cases where the interference is fully constructive or fully destructive.

In case it's of any help, here are the details of the mathematics. Denoting the factor by which the amplitude gets multiplied upon the exterior reflection by $$r$$, we have the following factors:


 * $$r$$ for the exterior reflection
 * $$1 + r$$ for transmission into the film
 * $$-r$$ for each internal reflection
 * $$1 - r$$ for transmission out of the film

Also we incur some phase factor $$\Delta$$ for each traversal of the film. Then we get the following series for the sum of the amplitudes of the transmitted rays:

$$(1 + r) \Delta (1 - r) + (1 + r) \Delta (-r) \Delta (-r) \Delta (1 - r) + \ldots$$

$$=(1 + r) (1 - r) \Delta (1 + (\Delta r)^2 + \ldots)$$

$$=(1 - r^2)\Delta / (1 - (\Delta r)^2)$$

Taking the squared magnitude of this yields the total transmittance. The phase factor $$\Delta$$ doesn't change the magnitude, so with $$\Gamma = \Delta^2$$, the phase factor incurred by a double traversal of the film, and with $$R = r^2$$, the reflectance of a single interface, we get the total transmittance

$$\left|\frac{1 - R}{1-R\Gamma}\right|^2$$

The total reflectance is just one minus this; it could also be obtained by summing the amplitude factors of the reflected rays:

$$r + (1 + r)\Delta(-r)\Delta(1 - r) + (1 + r)\Delta(-r)\Delta(-r)\Delta(-r)\Delta(1 - r) + \ldots$$

$$=r + (1 - r^2) (-r) \Gamma (1 + r^2\Gamma + \ldots)$$

$$=r - r \Gamma (1 - r^2) / (1 - r^2\Gamma)$$

Here the first $$r$$ represents the exterior reflection, and the other term represents the sum of all subsequent reflections. Since the exterior reflection doesn't suffer the $$1 - r^2$$ attenuation from the two transmission processes (which is very significant at high reflectances), it forms a term by itself, whereas the second reflection contributes the first term in a geometric series whose sum at high reflectances is much larger than just the second reflection.

I hope that was sort of clear... Fpahl 03:10, 7 Oct 2004 (UTC)

The Feynman Interpretation of quantum mechanics treats the paths from the inside, and outside surfaces in terms of probability amplitudes. These are described by Richard Feynman in his introductory lectures on quantum mechanics as spinning arrows like the hands on a clock. When two paths take the same time from source to a specific point on a detector the arrows spin for the same amount of time, and stop pointed in the same direction. The arrows are added together head to tail making a longer arrow. This is amplification of the probability a photon will hit the detector at that point. As the time to go two different paths from source to a point on the detector are evaluated the time the arrows spin are compared. When the arrows point in opposite directions adding the arrows results in zero amplification of the probability a photon will hit the detector there. 2600:8807:5400:600:FCBB:98A6:DC9C:7753 (talk) 13:45, 24 April 2024 (UTC)

Glue-based bubbles?
How do you call that organic solvant-based yellowish or brownish glue in English? There are some people who use this gue to blow large and durable bubbles. It's actually a dangerous glue that you don't want to inhale. Makers of that glue have to add mustard oil in it to stop kids from inhalation. -- Toytoy 08:31, Jan 1, 2005 (UTC)

New colored bubbles
I just read about an inventor using 10+ years inventing colored soap bubbles. They're schedualed for release Febuary 2006 called Zubbles (www.zubbles.com) The story I read: http://www.popsci.com/popsci/science/0a03b5108e097010vgnvcm1000004eecbccdrcrd.html
 * yah, already an entry at Zubbles. :) --Quiddity 19:16, 28 November 2005 (UTC)

color bubbles
i heard on NPR a few months ago about a guy who just invented solid color bubbles. he said they'd be for sale starting this summer or spring. how can i get more info? Kingturtle 02:14, 22 February 2006 (UTC)


 * Zubbles! :) --Quiddity 03:36, 22 February 2006 (UTC)

Fact change that doesn't seem right
 (Ignore the deletion of the bottom of the page this is a glitch in Wikipedia)

I reverted this edit because it was a fact changes that didn’t seem like it was true.
 * 1) One can make a bubble out of pure substances other than water
 * 2) The air pressure in the bubble can't decrees due to temperature because it was blown at that temperature and has noting to do with touching a surface. Maybe somebody should expand on that.
 * This sounds like Supercooling. Simular to Supersaturation or Superheating And the premis behind Ice-nine.--E-Bod 23:56, 1 May 2006 (UTC) shorten --E-Bod 00:01, 2 May 2006 (UTC)

Guiness Records
Under this site you can find some informations about Guiness Records related with soap bubble. I suggest to expand this article about these records. Visor 12:13, 3 May 2006 (UTC)

Salt in bubble solution
One of the formulae given is
 * 100 g sugar
 * 2 to 3 tablespoons salt
 * 1.4 L water (distilled water is better)
 * 150 ml dish washing detergent
 * 12 ml glycerin

While most of the components are explaied earlier, there is no explanation why salt is an improvement.

(Going metric for the rest of the formulae would also be useful for the world outside the US.) --12:36, 24 June 2006 (UTC)

Fair use rationale for Image:Zubble.JPG
Image:Zubble.JPG is being used on this article. I notice the image page specifies that the image is being used under fair use but there is no explanation or rationale as to why its use in this Wikipedia article constitutes fair use. In addition to the boilerplate fair use template, you must also write out on the image description page a specific explanation or rationale for why using this image in each article is consistent with fair use.

Please go to the image description page and edit it to include a fair use rationale. Using one of the templates at Fair use rationale guideline is an easy way to insure that your image is in compliance with Wikipedia policy, but remember that you must complete the template. Do not simply insert a blank template on an image page.

If there is other fair use media, consider checking that you have specified the fair use rationale on the other images used on this page. Note that any fair use images uploaded after 4 May, 2006, and lacking such an explanation will be deleted one week after they have been uploaded, as described on criteria for speedy deletion. If you have any questions please ask them at the Media copyright questions page. Thank you.

BetacommandBot 11:24, 6 July 2007 (UTC)

Minimum area?
I don't believe the several-times-repeated minimum area bit.

Clearly this isn't true for bubbles (its min area for a given volume).

Observationally, it isn't true for cylindrical films supported by circles above and below (they bow in at the middle; I think I understand this thinking about balance of forces: if the film *was* cylindrical the up-and-down forces would cancel in the middle but the around-forces would both be pulling inwards, and it would bow in. And indeed it does).

William M. Connolley 23:04, 11 July 2007 (UTC)


 * I'm five years late here, but the minimal surface connecting two circles does bow at the middle, just like a soap bubble: Catenoid. The minimal surface article explains that a minimal surface has a mean curvature of zero. Basically, the balancing of forces you described leads to a surface with a mean curvature of zero. If the mean curvature of a soap bubble was not zero, forces would be in imbalance. 209.131.76.183 (talk) 18:15, 9 July 2012 (UTC)

proposal for article text idea.
I want to add a link and sentence regarding a photograph recently taken of a soap bubble bursting. this article link is from a respected UK newspaper, the Telegraph. just wanted to mention this. thanks. --Steve, Sm8900 (talk) 19:42, 14 July 2009 (UTC)
 * I personally think that it's not worth including. All that we could add is 'someone took a photo of a bursting bubble'. The news story is from the 'weird news' section of the website, and doesn't give a hint as to why this is worth reporting - is it the first time someone has achieved this? Furthermore, the story claims the shot had been taken with a high speed camera, which is incorrect. According to the creators flickr posting, a Nikon D90 DSLR was used. Rror (talk) 22:39, 14 July 2009 (UTC)
 * hmmm. sorry, no, it's the photo itself which i think people would find interesting. it provides an interesting insight into the physics of bubbles in an accessible way. and if we don't link to it, there will be no way for others to find it. --Steve, Sm8900 (talk) 13:37, 15 July 2009 (UTC)
 * Ah, so you mean like this: WP:LINKFARM? Rror (talk) 16:31, 15 July 2009 (UTC)
 * :-) Errrm, no, I mean a small fact which adds some value to an interesting article. I think this is rather beneficial. --Steve, Sm8900 (talk) 15:40, 16 July 2009 (UTC)
 * Hi. so far, it appears that we have not received any further response to this discussion. if no further replies are received, I hope to add this text within the next few days. thanks. --Steve, Sm8900 (talk) 15:59, 21 July 2009 (UTC)

Commas
''"Soap bubbles usually last for only a few moments and then burst either on their own or on contact with another object." - there are no commas in this sentence, where they are required.''
 * No commas are required in this sentence.04:50, 6 October 2009 (UTC) —Preceding unsigned comment added by 169.231.34.158 (talk)

Gallery formatting
There is a gallery of several diagrams with accompanying text in the "Interference and reflection" section, which sticks out of the margin on the page. Since it has so much text with it, I thought maybe it should be formatted differently, anyway. Any ideas? B7T (talk) 15:30, 28 June 2010 (UTC)
 * Since nobody's suggested any other ideas, I went ahead and made the gallery narrower. This does make the text of the diagrams a bit less readable (although I can still read them personally), but they were already fairly small, and people can click on the images to see them larger, anyway.  I still don't think this is ideal.  It might look better if it was more like the section just above it, with paragraphs and floated images, and given its own section heading or subheading; or maybe it should be merged altogether with that section, with text of the captions integrated with that text. B7T (talk) 14:35, 1 February 2011 (UTC)

Frozen soap bubble temeperatures
I inserted the picture FrozenSoapBubble.jpg to the section "Freezing". The picture was taken at -17°C, but the text claims that this happens only at temperatures below -25°C. I did some internet seaching and found someon claiming, this happens at temperatures below -10°C (1st link, German language). Since German is my native language, I inserted a section "Gefrorene Seifenblasen" (Frozen soap bubbles) in "Seifenblase" (Soap bubbles) in German Wikipedia:

wich my attempt of a translation

The Englisch section here reads

This is very different. I seached the history of "Soap bubble", but the temperatures were insertey by IP users. There is a 5 month old "citation needed". Should I replace this with the paragraph above? Can anyone improve my paragraph to be proper English? -- Mmru (talk) 19:23, 8 April 2012 (UTC)

Why do the bubbles change colours then burst when blown on?
When I was a kid I noticed that if I blew on a bubble such that I would repeatedly push the surface of the film in one direction the bubble would start changing colours. It would go from its usual rainbow colour to a red, then green, then blue then white then eventually darken and burst. What is causing this effect and could it be briefly mentioned in the article if relevant?

37.152.211.176 (talk) 16:40, 12 May 2018 (UTC)


 * OK it looks like it happens because the thickness of the bubble is changing - http://www.exploratorium.edu/ronh/bubbles/bubble_colors.html.
 * 37.152.211.176 (talk) 16:46, 12 May 2018 (UTC)

History
It would be nice to include the history of making bubbles with a device like a bubble wand or bubble pipe. How long ago was this first discovered?50.205.142.50 (talk) 04:30, 29 June 2020 (UTC)

Soap Bubbles
Soap Bubbles are caused due to surface tension. Fluids do not have that much surface tension required to make bubbles. When soap or any or fluid containing a higher surface tension, is added to the fluid i.e,water, a d when air come in co tact with the solution it produces bubbles. Bubbles generate a magnetic field and they can be controlled by air. For example(what happened with me): Blow a bubble let it rest in air for some time. When it is about 1-1.5 inches above the ground generate air using your hands and you'll observe that the direction in which you move your hand the bubble will also move(make sure that your hand doesn't touch the bubble and it should be at a distance of 5-6 centimeters. Michael Ferrade (talk) 06:45, 3 November 2020 (UTC)


 * Ferrade: your claims are, imho, wrong. Please provide peer-reviewed citations. Thanks. 207.155.85.22 (talk) 19:29, 21 March 2022 (UTC)

Shape
The article needs a heavy rewrite. I'm old-fashioned so it seems to me that describing ONE (isolated) soap bubble should precede the discussion of merged bubbles. It also seems to me that a discussion of the (arguably) two prominent physically observed characteristics, shape and color, ought to come first - ALONG WITH THEIR CAUSES. The interference colors are sorta discussed but without discussing WHY they (obviously and visually) change rapidly, the reader is left with words instead of understanding.(hint: drainage and evaporation.) I have no problem with a discussion of a liquid film preceding discussion of a soap bubble. Or discussion of a spherical film. The problem that I have is that many, if not most soap bubbles are NOT spheres, and even if we separate the bubbles existing on liquid or solid surfaces (clearly NOT spheres!!), a bubble moving thru the air will only be approximately spherical (depending on the forces (air currents, etc.) on it. If I were doing it, I'd start with a soap bubble aloft and describe it as approximating a sphere as (some of) the liquid in the film drains and evaporates. And then I'd move on to the 'molecular' nature of the film wall. Introduction of curvature, etc. *should* be delayed because they're simply not necessary until merged bubbles, foams, and semi-spherical bubbles on surfaces are discussed (later!). And don't forget that as a bubble is "blown" its shape may oscillate!! Easy to understand (conservation of momentum), but outside surface tension/energy theory.207.155.85.22 (talk) 20:11, 21 March 2022 (UTC)