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Mathematicians Show Why Bubbles Sink in Nitrogen-Infused Stouts

Unknown Lamer posted more than 2 years ago | from the don't-get-caught-in-the-beer-vortex dept.

Beer 55

SicariusMan writes "The age old question: do Guinness and other stouts' bubbles really sink, or is it an optical illusion? Well, some mathematicians have figured it out." Full paper via arXiv; From the article: "To analyze the effect of different glass shapes, the mathematicians modeled Guinness beer containing randomly distributed bubbles in both a pint glass and an anti-pint glass (i.e., an upside-down pint). An elongated swirling vortex forms in both glasses, but in the anti-pint glass the vortex rotates in the opposite direction, causing an upward flow of fluid and bubbles near the wall of the glass."

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Wow! Such a thing! Allow me to violate... (-1)

Anonymous Coward | more than 2 years ago | (#40157233)

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Re:Wow! Such a thing! Allow me to violate... (-1)

Anonymous Coward | more than 2 years ago | (#40157295)

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Re:Wow! Such a thing! Allow me to violate... (0)

Jeremiah Cornelius (137) | more than 2 years ago | (#40159463)

It'll grow your dingus, massage your warbles and drink your sploodge!

Re:Wow! Such a thing! Allow me to violate... (0)

j00r0m4nc3r (959816) | more than 2 years ago | (#40159997)

It does all three things??

Re:Wow! Such a thing! Allow me to violate... (1, Insightful)

Anonymous Coward | more than 2 years ago | (#40157347)

Violate THIS!

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Re:Wow! Such a thing! Allow me to violate... (-1)

Anonymous Coward | more than 2 years ago | (#40157499)

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Re:Wow! Such a thing! Allow me to violate... (0)

Anonymous Coward | more than 2 years ago | (#40157973)

I got buddies who died face down in the much

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Re:Wow! Such a thing! Allow me to violate... (1)

couchslug (175151) | more than 2 years ago | (#40158927)

"I'll have you know the Supreme Court has roundly rejected prior restraint."

Unless Slashdot is now the US government, that decision doesn't apply.

Now that I know the theory (5, Funny)

cristiroma (606375) | more than 2 years ago | (#40157267)

Allow me to practice ...

Re:Now that I know the theory (0)

Anonymous Coward | more than 2 years ago | (#40157411)

I've tried drinking Guinness upside-down. Fun but messy.

Even more fun and more messy was the Guinness on the train returning from Belfast to Dublin.

With the train underway, an accomplice pours drink from out of window at beginning of the carriage, while we took turns sticking our heads out of a window a few meters further down. Not much beer drunk, and had to be quick to avoid the trees.

The joys of junior cup rugby (15 years old), and now we learn it was all in the name of science.

I'll drink to that.

Beer... (0)

Anonymous Coward | more than 2 years ago | (#40158033)

just wants to be free*.

* Free as in information - uuuurrrrrp! ('scus me! And CO2).

Next up: (-1)

Anonymous Coward | more than 2 years ago | (#40157277)

Researchers learn to spell.

late to the party (5, Informative)

Anonymous Coward | more than 2 years ago | (#40157313)

The Australians figured it out 12 years ago

http://science.slashdot.org/story/00/01/11/2156213/why-bubbles-in-guinness-fall

And no wonder (1)

Anonymous Coward | more than 2 years ago | (#40157515)

Australians do not like any confusion or doubt when it comes to beer. Mind you, apparently they initially thought it happened because Guiness comes from the North.

Re:late to the party (5, Funny)

NatasRevol (731260) | more than 2 years ago | (#40157819)

Yeah, but the new research had to make sure it wasn't the Coriolis force!

Re:late to the party (1)

_anomaly_ (127254) | more than 2 years ago | (#40157907)

So? If you were in a position to justify such an experiment, wouldn't you do it, without any regard to prior studies? Count me as one vote for the "best experiment subject of the year" award.

Re:late to the party (1)

buchner.johannes (1139593) | more than 2 years ago | (#40158035)

Link (in there) doesn't work anymore, and I can't find it.

Re:late to the party (0)

Anonymous Coward | more than 2 years ago | (#40162485)

The work [sciencenews.org] was done by Clive A.J. Fletcher, University of New South Wales, Centre for Advanced Numerical Computation in Engineering and Science (CANCES)

Re:late to the party (1)

ae1294 (1547521) | more than 2 years ago | (#40158749)

The Australians figured it out 12 years ago

http://science.slashdot.org/story/00/01/11/2156213/why-bubbles-in-guinness-fall

Yes but the math starts getting real dense midway in just about the time the author starts using 'yourmothersawhore' as a delta function. The last few pages seem to be completely unrelated work on chaos theory but I'm not sure that was intentional.

Re:late to the party (3, Funny)

Geek70 (2503888) | more than 2 years ago | (#40159441)

The underlying principle in science is to form a model and then test for confirmation or error. Clearly these dedicated professionals were testing in the name of science in case other forces were involved! In fact, I should do my part and run some tests of my own. I might also test some principles regarding gravity while I'm at it....

Re:late to the party (2)

camperdave (969942) | more than 2 years ago | (#40160729)

It's easy to see why this would be so in Australia. They're on the bottom of the world, and bubbles go up.

Re:late to the party (0)

Anonymous Coward | more than 2 years ago | (#40162845)

Did anyone else just feel very old? A link to a 12 year old story on slashdot?

Yup (0)

Anonymous Coward | more than 2 years ago | (#40163597)

and a dupe at that

American fluid dynamicists did it first! (4, Informative)

Colonel Korn (1258968) | more than 2 years ago | (#40157361)

Twelve years ago an almost identical paper was on the office wall of a chemical engineering professor I had in college. I'm mostly kidding with my subject line - I expect there's novelty in the new paper and just want to point out that this has been used as a model system (probably many times) before now.

party pooper (4, Funny)

G3ckoG33k (647276) | more than 2 years ago | (#40157425)

That's an astout observation!

Hence, no stout for you, mister. ;)

Re:party pooper (3, Funny)

Hognoxious (631665) | more than 2 years ago | (#40160189)

You sound bitter.

Re:party pooper (1)

BluBrick (1924) | more than 2 years ago | (#40160541)

Lager men than he would overcome that character defect.

Re:American fluid dynamicists did it first! (1)

r_batty_00 (233422) | more than 2 years ago | (#40162649)

Twelve years ago an almost identical paper was on the office wall of a chemical engineering professor I had in college. I'm mostly kidding with my subject line - I expect there's novelty in the new paper and just want to point out that this has been used as a model system (probably many times) before now.

I believe you are referring to Md Nurul Hasan Khan. In 1999 he published a paper proving Guinness bubbles fall. As far as I know he was the first.

http://www.smh.com.au/articles/2004/03/19/1079199418340.html [smh.com.au]

Is it replicatable? (2, Funny)

chill (34294) | more than 2 years ago | (#40157367)

I believe this study will end up receiving more than its fair share of replication and confirmation studies.

In fact, I can see several follow-up studies on if (and possibly why) this is specific to stout. How about a nice lager "control group" for the lads at table 3?

Re:Is it replicatable? (3, Informative)

krotkruton (967718) | more than 2 years ago | (#40158509)

It's not because they're stouts, it's because nitrogen is used in making certain stouts (in this case, the title was better than the summary). Non-nitrogen stouts won't work. For example, Left Hand Brewery has a Milk Stout and a Milk Stout Nitro; only the Nitro has the cascade. Unless you find a nitrogen lager, there's really no experiment to be had.

Re:Is it replicatable? (3, Informative)

BattleApple (956701) | more than 2 years ago | (#40158649)

Boddington's pub ale uses nitrogen, and it exhibits the same behaviour as Guinness.. it's interesting to see the effect in a clear fluid

Re:Is it replicatable? (1)

zippthorne (748122) | more than 2 years ago | (#40162459)

the category of ale encompasses many beers, including stouts like Guinness.

It does not, however, encompass lager, which if Budweiser is representative, is a category of beer whose terrible flavor is only mitigated by its incredible weakness.

Re:Is it replicatable? (2)

Mindcontrolled (1388007) | more than 2 years ago | (#40164615)

Fortunately, Budweiser is not representative. Lager comprises the Bavarian pale lagers, including Maerzen, i.e. the Oktoberfest beer. Heck, bock beer is a subcategory of Lager - not exactly incredible weak there...

Re:Is it replicatable? (1)

BattleApple (956701) | more than 2 years ago | (#40172975)

An ale is still not always a stout. If a stout is basically an ale made with roasted malt, the question could be it's something to do with the malt and not the yeast.

Bud is disgustingly weak as far as flavor, but higher alcohol content than I thought. (5%abv) I always thought it was around 3 or 4. I'll stick with my 8 - 12% IPA's

Re:Is it replicatable? (0)

Anonymous Coward | more than 2 years ago | (#40158765)

+1 for Left Hand Milk Stout

-Cheers

Re:Is it replicatable? (1)

treeves (963993) | more than 2 years ago | (#40160827)

Next study: helium-3 infused stouts vs. non-helium-3 infused stouts.

I thought... (2)

bobbied (2522392) | more than 2 years ago | (#40157465)

I thought it was just a side effect of drinking the stuff.... Like the floor smacking me in the face... Hey, bar-keep! Keep'm coming until the bubbles start sinking...

DO NOT (4, Funny)

Fned (43219) | more than 2 years ago | (#40157527)

...I repeat DO NOT touch a pint glass and an anti-pint glass during a toast.

That is all.

Re:DO NOT (2)

Eli Gottlieb (917758) | more than 2 years ago | (#40158321)

They'll annihilate each other, leaving you with nothing but a piece of bread.

Re:DO NOT (3, Funny)

idontgno (624372) | more than 2 years ago | (#40158541)

Only after a rather stout explosion, though.

Re:DO NOT (1)

ae1294 (1547521) | more than 2 years ago | (#40158571)

Do not touch pint glass with anti-pint glass in remaining space/time...

Re:DO NOT (1)

sharkey (16670) | more than 2 years ago | (#40159093)

Do not cross the stouts?

Messy experiment (0)

Anonymous Coward | more than 2 years ago | (#40157583)

I ran the experiment using an anti-stout glass but my results differed from the theory in original paper - instead of the bubbles rising, they ran all over the floor.

Re:Messy experiment (1)

rickb928 (945187) | more than 2 years ago | (#40158375)

Bubbles got feet!

Location, location, location (2, Funny)

Anonymous Coward | more than 2 years ago | (#40157671)

Guiness is brewed in Ireland. The bubbles are made in Australia. When the can is opened the bubbles attempt to to up, but they are from Australia so they head the wrong way. Another pint of your finest, barkeep!

Re:Location, location, location (2)

digitig (1056110) | more than 2 years ago | (#40158273)

The bubbles are embarrassed at being full of nitrogen instead of carbon dioxide (as beer bubbles should be) and are trying to hide?

Re:Location, location, location (1)

Anonymous Coward | more than 2 years ago | (#40162289)

Qantas entanglement.

Math (1)

pcjunky (517872) | more than 2 years ago | (#40157947)

Their answer is "because the math says so"?

Negative ninety-nine bottles of beer on the wall. (5, Funny)

neoshroom (324937) | more than 2 years ago | (#40158071)

in the anti-pint glass the vortex rotates in the opposite direction, causing an upward flow of fluid and bubbles near the wall of the glass

Just don't drink too many anti-pints of beer. I tried it once and woke up with a hell of a hangunder.

Re:Negative ninety-nine bottles of beer on the wal (1)

CCarrot (1562079) | more than 2 years ago | (#40160823)

in the anti-pint glass the vortex rotates in the opposite direction, causing an upward flow of fluid and bubbles near the wall of the glass

Just don't drink too many anti-pints of beer. I tried it once and woke up with a hell of a hangunder.

Hangin out on the Disc [lspace.org] again? Bugarup. Millenium hand and shrimp, I says! :)

Beer research?.. Really (0)

Anonymous Coward | more than 2 years ago | (#40163289)

Come on.. Really? and they got someone to fund this beer research? Damn, those guys are smart!

This could put Ireland back into recession (1)

tackledingleberry (1109949) | more than 2 years ago | (#40164161)

At the end of the paper they tantalisingly open the door to the possibility that there might exist a glass which would allow Guinness to settle more quickly. If such a glass were discovered, Irish barmen (well, all barmen really) would be able to pull pints more quickly. This means that fewer barmen would be required to man a bar so barmen would lose their jobs, increasing unemployment and probably plunging the country (perhaps the world) further into recession. Risky research.

Re:This could put Ireland back into recession (1)

Palamos (1379347) | more than 2 years ago | (#40165991)

All pints of Guinness can be pulled quickly almost independently of the shape of the glass, the current two-stage pouring process was introduced as a marketing ploy some decades ago to make the beer somehow special. I'm not denying that the beer is special, only that it needs to be poured in any special way.
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