Ananova:

Stout proof of falling bubbles

Scientists have shown that the bubbles in a pint of Guinness really do move down instead of up.




To mark St Patrick's Day, a team of Scottish and US researchers has produced video evidence to show the bubbles being dragged to the bottom of the glass.

An earlier study concluded that the phenomenon may only have been an optical illusion.

Close examination reveals that as the pint settles, bubbles touching the walls of the glass experience drag that prevents them floating up.

Bubbles in the centre of the glass, however, are free to rise. A circular flow is created, causing bubbles at the the edge to be pushed downwards on the inside surface of the glass.

Eventually more and more bubbles find their way to the head of the beer until the cycle loses momentum.

The effect occurs in any liquid, say the scientists, but the contrast between the dark stout and its creamy bubbles makes it easier to spot in Guinness.

The relatively small nitrogen bubbles in Guinness are also more easily pushed around and less able to dissolve than the carbon dioxide bubbles in soft drinks.

The Scottish scientists worked in collaboration with colleagues led by Professor Dick Zare at the University of Stanford in California.

They are the first to successfully capture the tiny, elusive bubbles on film, using a high-speed digital camera with a zoom lens in a chemistry laboratory.

As well as settling pub debates, the video could help improve scientists' understanding of fluid dynamics in a wide range of areas, including industry, medicine and oceanography.

It cures depression as well...or so Irish Scientists beleive...

and with a shot of gooood irsh whiskey dropped in its quite good!

Have to laugh over the things they are willing to research.....bet they had a good time doing it.

Never tried the two together, its an idea next time I'm near a store.

L-l-l-l-luuuuuussssssssssshhhhhhh.

Cures my depression...then again, so does Jameson in a cup of coffee

Waisting a good whisky by polluting it with coffee is depressing....

I can still drink it straight up...but now I need a Zantac chaser...oh the joys of aging!

I have a bottle of "Early Times" whiskey that I use as cough syrup. Works ok.

Theres this Bourbon that i like but i cant remember the name. It had a great smell, was smooth and seemed almost sweet... anyone got an idea of what that would be?

Let me narrow down the field so I dont get a blonde answer: Hey Duncan, got a guess at what that is?

(pun aimed at Laureen , ...but Galla you can be insulted too if you wish - more the merrier.)

I don't drink much anymore, so probably wouldn't be of much use...sorry hon, not insulted. LOL

Should be wrapping up some things on ebay today and be more into what's going on. Watch em like a hawk so I don't get canned on last minute stalkers.

Hmmm since I really do not drink hardly at all I would say it was probably Southern Comfort?? Maybe?
I like Crown Royal the best and always have. Hot totty's made with that brand is really good!

I have always made hottie toddys out of Brandy...still don't like em much. LOL

Blast. No, tthts not it i suppose there are several and I would need to smell and sniff around until i found the same one. Im not the drinker either - Ive never even had southern comfort.

Once or twice when much younger. SC is the sweetest on the market and I don't really care for it that much.
My favorite is still Guinness Stout but alas don't get it much either. The price around here is around 14 dolors for 8 cans!
Now Coors on the other hand is cheaper then tap water and I always have hated that stuff.

Oh yeah, me too. [>a-hem<]
-uh, that stuff is terrible... yeah - Im a real beer drinker...
gatta say though that recently, i did try a bud light and it really did taste like water. i was surprised. (See, i have to run down another seperate brand of moat*#@er so i can still look good...)

I'm not running moat*#@er down, just saying my taste buds are warped!

Oh, so what? then if I offe you a nice Cold Coors or Bud or something youll accept it?

..and drink it???

nope, I'm a barbarian at heart so therefore don't care about social graces.

Good answer, Duncan. Good answer. We went shopping for the plane trip last night and Scott drinks moat*#@er got the brilliant idea to buy mixed drink stuff to make our flight a little easier to sleep and kick off the vacation so to speak. We ended up getting a fifth of Bacardi Gold, assorted tropical juices and coco lopez and even bought a blender. I think we are subliminaly missing Hawaii already...

I think, you guys are subconsciously acknowledging an end of a way of life and celebrating the start of another.
Hows the ladys taking all of this?

Ill answer this one...

See, cleave just ties his up in the yard.

Mine is good with it. Though she doesnt like the idea tthat I wont haave every waking moment to spend with her. If she had it her way she would be glued to my hip 24/7.

LOL I am hoping Steve's is a canine bitch? I know I wouldn't take well to being tied up in the yard....

Didn't know you all were headed on vacation...best of luck and safe journey to you both (better you than me) Never want to make another one of those flights to Hawaii...it is a smokers' hell. LOL

Remember to leave your clippers, files, guns, explosives, etc. at the house....they tend to frown on those things at the airports.

cameras, film canisters, shoes, carry on luggage and luggage under the plane, your body...clothing...and the last but not least
note book PC's get stolen far too often.

Ah - PC notebooks. One colleague of mine is just back from Hawaii (via LA, NY, London). His laptop was in a padded computer carrying case, inside a briefcase, in the overhead compartment. Still managed to crack the screen though. Clearly it's a bumpy ride !!!

It's my job to persuade the insurance company it really happened "by accident". He managed to damage another laptop earlier this year by SITTING ON IT - again, by accident.
Andrew

I hope Gala is right

Hope you had a good trip and a safe and joyous holiday.

As to the whole whiskey in the Guinness Stout, I don't think it a waste. I find Stout a bit bitter by itself, but those boiler makes were really smooth. I guess it gets you quicker too, which is why it was our Fraternity drink.

Of late I usually just drink Whiskey (most often straight with a soda chaser). Jack Daniel's. Oh, and have you heard they reduced the strength of it? It use to be 86 proof, now its 80 proof.....

AJR, good luck with the insurance company......must have been a very bumpy ride indeed.

Stout or beer in a large mug and whiskey in a shot glass was what I used to drink many years and life times ago.

hows that song go....wiskey for my men and beer for the horses.....

Scientists crack beer-froth enigma
Wed Apr 25, 12:40 PM ET


PARIS (AFP) - There is the nagging question of whether life exists other than on Earth. The enduring mystery of who made us -- and why.

And then there is this: Why does the foam on a pint of lager quickly disappear but the head on a pint of Guinness linger?

Answers to questions 1 and 2 are still being sought, but the Great Beer Riddle, at least, may soon be solved.

Writing in the prestigious British science journal Nature, an elite scientific duo say they have devised an equation to describe beer froth.

The breakthrough will not only settle the vexatious lager vs. stout debate, it will also help the quest to pour a perfect pint every time.

Beer foam is a microstructure with complex interfaces. In other words: a cellular structure comprising networks of gas-filled bubbles separated by liquid.

The walls of these bubbles move as a result of surface tension -- and the speed at which they move is related to the curvature of the bubbles. As a result of this movement, the bubbles merge and the structure "coarsens," meaning that the foam settles and eventually disappears.

Three-dimensional equations to calculate the movement have been made by Robert MacPherson, a mathematician at the Institute for Advanced Study in Princeton, New Jersey, and David Srolovitz, a physicist at Yeshiva University, New York.

They build on work by a computer pioneer, John von Neumann, who in 1952 devised an equation in two dimensions.

The mathematics of beer-bubble behaviour are similar to the granular structure in metals and ceramics, so the equation also has an outlet in metallurgy and manufacturing as well as in pubs.

who cares...as long as the cute bartender writes his phone number in the foam before serving it to me....
Slainte!