Irish Mathematicians Solve The Guinness Sinking Bubble Problem

I for one am glad to see that the great minds of our time are focusing on the important things....like a nice cold pint of Guinness ( For Strength !).  In my present location, such a thing of beauty is not available, but there will be plenty ready for me when I get some R&R.


Irish Mathematicians Solve The Guinness Sinking Bubble Problem -
Bubbles sink in Guinness because of the peculiar geometry of pint glasses, say a dedicated group of researchers at the University of Limerick


One of the more intriguing conundrums in fluid dynamics is the puzzling behaviour of bubbles in Guinness, the famous Irish stout.

As many drinkers will attest, the bubbles in Guinness appear to sink as the drink settles and the head forms. How can this be, given that bubbles are less dense than the surrounding fluid and so should rise?

Over the last ten years or so, physicists have begun to pick this problem apart. Most recently they've shown that it is not the bubbles that sink but the liquid, which circulates in a way that is downwards near the glass walls and upwards in the interior.  As long as the downward flow of the liquid is faster than the upward motion of the bubbles, they will appear to sink.

But that still leaves a puzzle: why does the liquid circulate in this way?

Today, a dedicated team of Irish mathematicians reveal the answer. Eugene Benilov, Cathal Cummins and William Lee at the University of Limerick say the final piece in this puzzle is the shape of the glass, which has a crucial influence over the circulatory patterns in the liquid.

To understand how, first remember that the motion of every bubble exerts a drag on the liquid around it. Now imagine what would happen if there were a region of liquid containing fewer bubbles near the wall of a pint glass and consequently a region of higher bubble density near the middle of the glass.

Benilov and co say that the drag will be higher in the region where the bubble density is higher, in other words near the centre of the glass. This creates an imbalance that sets up a circulation pattern in which the liquid flows upwards in the centre of the glass and downwards near the walls. 

That's exactly as observed in a pint of Guinness. But what causes the region of low bubble density near the glass walls in the first place?

Benilov and co imagine that to start with, the bubbles are distributed evenly throughout the liquid. In a perfect cylinder, they would simply rise together. The bubbles in each volume of liquid are steadily replenished from below. 

But imagine a container that is narrower at the bottom and wider at the top so that the walls rise at an angle, as in a pint glass. In this case, the simple act of bubbles rising creates a region of low bubble density next to the angled wall because the bubbles are not being steadily replenished below.

By contrast, the bubble density is higher in the middle of the glass because the bubbles are replenished from below.

That would set up exactly the circulation pattern that is observed, say Benilov and co.

This effect is well known in sedimentation theory as the Boycott e?ect. "It was ?rst observed in test tubes containing red blood cells when it was discovered that sedimentation times could be signi?cantly reduced by inclining the test tubes," say Benilov and co.

These guys have even created a computer model of bubble behaviour in Guinness which confirms their thinking.

The icing on the cake, however, is that there is a simple experiment that can easily confirm the theory.

Experiments are not usually the domain of mathematicians. But Benlivo and co demonstrate valour beyond the call of mathematical duty by actually performing the experiment in which they bravely pour Guinness into a cylinder. "If the container is tilted, bubbles will be observed to move upwards near its upper surface and downwards near its lower surface," they say.

They have even created a video of this experiment which you can download here (avi).

Of course, the essence of experimental science is repeatability. Many readers will not be content with mere visual evidence from a video but insist on repeating this experiment on their own terms, perhaps in a hostelry of their own choosing. Quite right.

But if you choose this route, remember that this work is not entirely whimsical. "Understanding these types of bubbly ?ows is important for a number of applications, such as manufacturing champagne glasses engraved with nucleation sites, and widget and similar technologies for promoting foaming in stouts," say Benilov and co.

Guinness drinkers (and servers) will also be aware of another problem that plagues them--the time it takes for a pint of Guinness to settle, which is significantly longer than with most ales and lagers.

Could this work allow pint glasses to be redesigned in a way that encourages stouts to settle more quickly?

We'll be following future developments closely.

Ref: arxiv.org/abs/1205.5233: Why Do Bubbles In Guinness Sink?
http://www.technologyreview.com/blog/arxiv/27880/?p1=blogs

Dave Cremin from Ireland with an amazing card trick

Dave Cremin from Ireland amazes the crowd....This one is a show stopper.

Spitfire diaries: The strange life in Dublin's POW camp

A colleague and I were discussing what we like to read the other day. I expounded that reading true history was the best as the real life adventures of people in our past surpass anything a writer could dream up....Here is a prima facie case of that....

" Gee Grandpa, what did you during WW2 ??"

" I was held at a POW Camp in IRELAND..."

" What ?? Ireland ?? Weren't they on our side??"

Not exactly.....This story is one for the books.....And also involves the recovery of a British Submarine Spitfire....awesome.


Spitfire diaries: The strange life in Dublin's POW camp
Dan Snow BBC.co.UK

An attempt to recover a Spitfire from a peat bog in Donegal will highlight the peculiar story of the men - both British and German - who spent much of World War II in relative comfort in neighbouring prisoner of war camps in Dublin, writes historian Dan Snow.

In Northern Ireland in 1941, a routine Sunday afternoon sortie by a pilot flying one of Britain's Spitfire fighters runs into difficulties.

Returning to base after flying "top-cover" for maritime convoys off the coast of Donegal, the Rolls Royce Merlin engine overheats and fails.

The pilot yells into his radio "I'm going over the side", slides back the bubble canopy, releases his seat straps and launches himself into the air.

The Spitfire is one of the most vaunted examples of British engineering's history. The greatest ever single-seat, piston-engined fighter, it had played a vital role during the Battle of Britain the year before.

Its design was so advanced that it became the only fighter aircraft in WWII that served on the front line from the first to the last day of the war. Bailing out was no easy task.

The air flow hit this particular pilot like a freight train and tore off his boots. Luckily he was able to deploy his parachute and landed in a peat bog. His aircraft smashed into the bog half a mile away.

It sounds like a typical wartime accident but it was anything but. It was the beginning of one of the strangest incidents of WWII.

Bud Wolfe was very keen to get back into action The pilot was 23-year-old Roland "Bud" Wolfe, an RAF officer from 133 "Eagle" Squadron, a unit entirely composed of Americans.

Bud himself was from Nebraska, one of a number of Americans who had volunteered to take up Britain's cause. Since the US was not yet at war with Germany when the men volunteered, the American government stripped Wolfe and others of their citizenship. These pilots were a mix of idealists and thrill seekers.

When Wolfe was found by the authorities he realised his, already unusual, situation was much more complicated than he had guessed. He had crashed over the border.

Since the South was neutral it had been decided that all servicemen of any belligerent nation that ended up on Irish soil through navigational error, shipwreck or other accident would be interned for the duration of the war.


Wolfe found himself heading not back to his airbase, RAF Eglinton, now Derry International Airport, in Northern Ireland just 13 miles away, but to Curragh Camp, County Kildare, 175 miles to the south.

Here, a huddle of corrugated iron huts housed 40 other RAF pilots and crewmen who had accidentally come down in neutral territory. They were effectively prisoners of war.

It was an odd existence. The guards had blank rounds in their rifles, visitors were permitted (one officer shipped his wife over), and the internees were allowed to come and go. Fishing excursions, fox hunting, golf and trips to the pub in the town of Naas helped pass the time.

But what was really odd was the proximity of the Germans.

It was not just the British and their allies who got lost above and around Ireland. German sailors from destroyed U-boats and Luftwaffe aircrew also found themselves interned. The juxtaposition of the two sides made for surreal drama.


Dublin stayed neutral in 1939 - it was only 18 years since it secured partial independence after centuries of British rule

Taoiseach Eamon de Valera even paid his respects to German representative in Dublin when news of Hitler's death emerged

But Irish people were not all so impartial - a 2009 Edinburgh University study found more than 3,600 soldiers from the South died on active service

And in the British army alone, 100,000 Irish people served in WWII - half from the South

Sport was a notable feature. In one football match the Germans beat the British 8-3. There were also boxing contests.

It appears that the rivalry on the pitch followed the teams into the pub afterwards as well. They would drink at different bars, and the British once complained vigorously when the Luftwaffe internees turned up to a dance they had organised.

Anything further from front-line service is hard to imagine.

It may seem to us like a welcome chance to sit out the war with honour intact, plenty of distractions and no danger, but for Wolfe it was an unacceptable interruption to his flying activities.

On 13 December 1941 he walked straight out of camp and after a meal in a hotel, which he did not pay for, he headed into nearby Dublin and caught the train the next day to Belfast. Within hours he was back at RAF Eglinton where he had taken off two weeks earlier in his defective Spitfire.

He could not have expected what was to happen next. The British government decided that, in this dark hour, it would be unwise to upset a neutral nation.

The decision was made to send Wolfe back to The Curragh and internment. Back in the camp, Wolfe made the best of it, joining the fox-hunting with relish.

He did try to escape again but this time he was caught. Finally in 1943, with the US in the war, and the tide slowly turning, The Curragh was closed and the internees returned. Wolfe joined the US Army Air Force and served once again on the front line.

So great was his love of flying that he also served in Korea and even Vietnam. He eventually died in 1994.

But Wolfe's epic story did not end with his death. Thanks to the highly unusual, soft nature of the terrain in the peat bog where his Spitfire crashed, a team of archaeologists is attempting to dig up his aircraft.

This week I will accompany them with a BBC television crew and record what we hope will be substantial pieces of wreckage emerging from the bog. The bog defeated the attempt in 1941 to gather up the wreckage, so there should be plenty of Spitfire down there, but it may well defeat us.

The Eagle Squadrons allowed Americans to fight before the US entered the war The digger has to sit on bog mats, big railway sleepers, to spread its 20-ton weight. But even they may not be enough to stop it sinking in. There is also a danger that the hole will simply fill with water or the sides cave in.

It is one of the most difficult excavations that an experienced team have ever faced. Whatever happens, I will be updating Twitter minute-by-minute as the excavation takes place.

Hopefully we will find the physical evidence that will shine a light on the events of that November night 70 years ago and also provide us with a connection to one of the most bizarre moments of the war

The Pot of Gold at the end of the Rainbow.....

The Irish leprechaun's secret hiding place for his pot of gold is usually said to be at the end of the rainbow. This place is impossible to reach, because the rainbow is an optical effect which depends on the location of the viewer. When walking towards the end of a rainbow, it will appear to "move" further away...

This phenomena has been documented in the enclosed photograph....Saints be praised.

Was St. Brendan, an Irish monk in the 6th century the first to discover America???

This is an interesting idea....was an Irish Monk the first person from Europe to discover America??? Maybe him & the lads were out looking for some grains to make some brew and got lost.....interesting idea....one to debate over a tall glass of Guinness....or two.......

Was an Irish monk the first European to reach America?
by Josh Clark

Christopher Columbus gets the lion’s share of the credit for discovering America in 1492, but the evidence weighs heavily against him being the first one to find the New World. If Columbus had actually discovered America, he'd have found an unpopulated terrain, and of course, he didn’t. Anthropologists and archaeologists estimate that between 40 and 100 million Native Americans lived in the Americas when Columbus arrived, accounting for as much as one-fifth of the global population at the time [source: Mann]. Besides, some believe the Chinese beat Columbus by 80 years.

While Columbus may have been the first European to reach Central America, it is Giovanni Caboto who is the first to have arrived in North America, landing in Labrador, off the east coast of Canada, in 1497. So now we know, ­then: It was Caboto who was the first European to land in North America, right? Wrong again.

Caboto was beaten to North America by 500 years by the Vikings. Definitive proof of Norse habitation of Newfoundland, near Labrador, can be found at L’Anse aux Meadows, a Viking settlement dating to around 1000 C.E. The Vikings are the earliest group to leave behind tangible evidence of their presence. So were the Vikings the first? Not quite. Another group may have been the first Europeans to arrive in the New World: the Irish.

In the sixth century, St. Brendan, an Irish monk who was widely reputed as a skilled seafarer, is said to have undertaken an ambitious voyage. Brendan, along with a crew of fellow monks, sailed looking for Paradise, the Land of Promise of the Saints. After seven years exploring mysterious lands, he came upon what he believed to be the fabled paradise. It was an island so vast that he and his crew failed to reach the far shore after 40 days of walking. It contained a river that was too wide to be crossed. It was a wooded land, filled with lush fruits. He and his men filled their boats with gems they found there and returned home to tell of the news.

It wasn’t until the ninth century that an account of Brendan's voyage surfaced, the Navigatio Sancti Brendani (“Travels of St. Brendan” in Latin). It was an instant hit, translated into several languages. The account talks of Brendan’s experiences, including his being pelted with rock from an island of fire, seeing a pillar of crystal and encountering a moving island before finally coming upon the Promised Land, which came to be referred to as the Fortunate Islands.

But as time wore on, the Navigatio -- along with St. Brendan himself -- passed into the realm of legend. If Brendan had lived -- as most scholars assume -- surely he couldn’t have traveled across the treacherous North Atlantic with the technology available at the time. Certainly, he couldn’t have beaten the Vikings to North America.

Ironically, it is Viking lore that lends support to the idea that Brendan was the first European in North America.

St. Brendan -- or Somebody

One of the biggest problems with the idea that St. Brendan and his crew were the first Europeans to arrive in North America is the dearth of physical evidence to support this claim. Unlike the Vikings, there is no settlement that proves the Irish were here prior to other Europeans. At one time, however, tantalizing physical evidence did emerge.

Barry Fell, a Harvard marine biologist, discovered some petroglyphs -- writings carved into rock -- in West Virginia in 1983. Fell concluded that the writing was Ogam script, an Irish alphabet used between the sixth and eighth centuries. Even more startlingly, Fell found that the message in the rock described the Christian nativity. But shortly after Fell released his findings, many in the academic community attacked his interpretation of the petroglyphs. Many scholars question his methods and refuse to accept his findings as fact. Although the petroglyphs could be Ogam script, their true origins and meaning remain unproven [source: Oppenheimer and Wirtz].

All that's left, then, is the written accounts of Brendan's voyages. The Navigatio reads like a fantastic account, laden with Biblical references -- one passage recounts how Brendan held Communion on the back of a whale. In the mind of most historians, this story puts the document in the realm of folklore. Even for those researchers who put stock into the Navigatio's underlying historical accuracy, many of the directions don't point to North America as the destination where Brendan ultimately landed. But there are documents that suggest an Irish presence in North America prior to the Vikings', including the accounts of the Vikings themselves.

The Irish were known to the Norse (Vikings) as a seafaring group that had traveled far further than the Vikings had. In their sagas -- accounts of their people's exploits -- the Vikings speak of finding Irish missions when they arrived in Iceland in the 10th century. Another saga tells of meeting Native Americans who were already familiar with white men. These indigenous peoples had already encountered explorers who dressed in white and came from a land "across from their own" [source: Lathe]. A third saga relates that the Norse encountered a tribe of indigenous Americans who spoke a language that sounded like Irish, with which the Norse were familiar.

St. Brendan was reputed as a skilled voyager, establishing missions wherever he landed. Historians generally accept that he was able to sail to Europe and islands near Ireland. But, say the skeptics, this is a far cry from crossing the North Atlantic in a curragh. This small, open vessel, made of a wooden frame covered by ox hide and waterproofed with tar, was the only seafaring technology available to the Irish during Brendan's lifetime. It was long doubted that such a boat could make the trip from Ireland to America.

But this was proven incorrect in 1976 by author and adventurer Tim Severin, who built a curragh and set out from Ireland -- just as Brendan would have. He retraced the route that Brendan is thought to have taken, from Ireland to Iceland, Greenland and eventually Newfoundland. After a year-long voyage, Severin made it, proving that the trip was at least possible in such a craft.

Severin himself admits that his experiment is a long way from definitive proof that Brendan actually made the trip. As he wrote in "The Brendan Voyage" -- his account of the experiment -- "the only conclusive proof that it had been done would be if an authentic relic from an early Irish is found one day on North American soil" [source: Wiley].

One of the biggest problems with the idea that St. Brendan and his crew were the first Europeans to arrive in North America is the dearth of physical evidence to support this claim. Unlike the Vikings, there is no settlement that proves the Irish were here prior to other Europeans. At one time, however, tantalizing physical evidence did emerge.

Barry Fell, a Harvard marine biologist, discovered some petroglyphs -- writings carved into rock -- in West Virginia in 1983. Fell concluded that the writing was Ogam script, an Irish alphabet used between the sixth and eighth centuries. Even more startlingly, Fell found that the message in the rock described the Christian nativity. But shortly after Fell released his findings, many in the academic community attacked his interpretation of the petroglyphs. Many scholars question his methods and refuse to accept his findings as fact. Although the petroglyphs could be Ogam script, their true origins and meaning remain unproven [source: Oppenheimer and Wirtz].

All that's left, then, is the written accounts of Brendan's voyages. The Navigatio reads like a fantastic account, laden with Biblical references -- one passage recounts how Brendan held Communion on the back of a whale. In the mind of most historians, this story puts the document in the realm of folklore. Even for those researchers who put stock into the Navigatio's underlying historical accuracy, many of the directions don't point to North America as the destination where Brendan ultimately landed. But there are documents that suggest an Irish presence in North America prior to the Vikings', including the accounts of the Vikings themselves.

The Irish were known to the Norse (Vikings) as a seafaring group that had traveled far further than the Vikings had. In their sagas -- accounts of their people's exploits -- the Vikings speak of finding Irish missions when they arrived in Iceland in the 10th century. Another saga tells of meeting Native Americans who were already familiar with white men. These indigenous peoples had already encountered explorers who dressed in white and came from a land "across from their own" [source: Lathe]. A third saga relates that the Norse encountered a tribe of indigenous Americans who spoke a language that sounded like Irish, with which the Norse were familiar.

St. Brendan was reputed as a skilled voyager, establishing missions wherever he landed. Historians generally accept that he was able to sail to Europe and islands near Ireland. But, say the skeptics, this is a far cry from crossing the North Atlantic in a curragh. This small, open vessel, made of a wooden frame covered by ox hide and waterproofed with tar, was the only seafaring technology available to the Irish during Brendan's lifetime. It was long doubted that such a boat could make the trip from Ireland to America.

But this was proven incorrect in 1976 by author and adventurer Tim Severin, who built a curragh and set out from Ireland -- just as Brendan would have. He retraced the route that Brendan is thought to have taken, from Ireland to Iceland, Greenland and eventually Newfoundland. After a year-long voyage, Severin made it, proving that the trip was at least possible in such a craft.

Severin himself admits that his experiment is a long way from definitive proof that Brendan actually made the trip. As he wrote in "The Brendan Voyage" -- his account of the experiment -- "the only conclusive proof that it had been done would be if an authentic relic from an early Irish is found one day on North American soil" [source: Wiley].

Why Guinness tastes better on the Emerald Isle than anywhere else in the world

The reputation that Guinness has as the world's finest brew is well deserved...I for one, prefer it over all other forms of brew.....maybe I am a bit of a Guinness snob, but that is the way it is....you can drink your other brews but for a true enjoyable brew, you can't beat one that has been brewed in the same location since 1759....why that out dates the USA !!

So this info doesn't surprise me....I'll toast a few on St. Patty's day and I advise you to do the same...Enjoy !

Stout of Ireland: Why Guinness tastes better on the Emerald Isle than anywhere else in the world
By Daily Mail Reporter
7th March 2011

It's one of the most stoutly contested Irish boasts in bars the world over.
But scientists claim to have settled the score once and for all: Guinness tastes better in Ireland than anywhere else.

Experts from the Institute of Food Technologists carried out extensive taste surveys in 33 cities in 14 countries to find the best place for a pint of the black stuff.
And the majority of testers said they enjoyed a pint of plain in Ireland far more than in any other location.

The study, which claims to be the first to scientifically prove that the stout doesn't travel well, used 'non-expert' tasters, each from different countries, to conduct the test.

It took 103 in 71 different pubs where factors such as pub ambience, Guinness appearance, flavour, and aftertaste were all considered.

Using a Visual Analogue Scale which ranks enjoyment from 1-100, Guinness drinking in Ireland averaged a score of 74, compared to just 57 anywhere else.

Pete Brown is a celebrated beer author who toured the world searching out the local tipple for his book 'Three Sheets to the Wind'.

He said a Guinness in Ireland marks the end of a pilgrimage for beer lovers, and it is no surprise they enjoy it more there than anywhere else.

He said: 'Drinking Guinness in Ireland is always going to be more enjoyable than in London or Paris, or anywhere else.

'There is a feeling of authenticity that you associate with drinking a beer in it's true home, so the ambience you feel in an Irish pub would be like no other.

'People will go to Dublin with the intention of ordering a pint of the black stuff, so you're already gearing yourself up for that satisfaction before it's passed your lips.

Although, he says, the sensation of having a 'proper' Guinness will heighten the drinker's enjoyment, he said there are also practical reasons the local drink will always taste better.

He said: 'In Irish pubs you can order a Guinness knowing that the tap has been flowing all day, so you'll never get a pint which has been sat in the pipes for an hour. Whereas in London, it could have been there all day.

'The locals also tend to know their own beer inside out, so you'll get it at the right temperature, in the right glass and with the right head. That's really important

The Lads in Ireland learn that sending " Top Ten" lists by e-mail was likely NOT the best idea they ever had...

Tis a sad, sad tale I need to tell ye....There be a group of Lads back in the Old Sod who are getting their bits put through the mill as they sent along a "Top 10" e-mail that rates and lists the lasses they would most like to have around...and like to other things with if they could.

The Lads never learned that in this day & age, anything ( and I mean ANYTHING)you put in an e-mail can & will be published around the world if you are not careful....Let's just say these guys don't even know what the word c-a-r-e-f-u-l means... must have missed that lesson at Business school.

I am sure this is causing a lot of serious discussions between the lads & their BOSSES - at work AND at the homefront.....tis a sad thing to see....The young lasses are a fine representation of Irish womanhood and are also likely NOT happy with the added attention.... Tis a storm that be brewing over the Emerald Isle...

Click on the picture to see a copy of the e-mail....

TOP TEN Office E-mail that;s scandalizing Ireland - Gawker.com

Accounting giant PricewaterhouseCoopers (PWC) is mired in scandal after a group of 17 male employees in Dublin started forwarding around a "top 10" list of their picks for the most attractive female employees in the office. We have it.

The frat boy behavior of 17 Irish PWC employees is quickly becoming an international incident. The company has already launched an investigation after the email was forwarded all over Ireland, and made its way into the newspapers there today:

"We are taking this matter extremely seriously and are launching a full investigation. We will take all necessary steps and actions in line with our firm's polices and procedures," PWC's human resources partner Carmel O'Connor said last night.

Accounting trade magazines have picked up the story; once it hits the British tabloids, it'll certainly be a PR nightmare for PWC—which has 2,000 employees in Ireland, and 160,000 worldwide. It's already circulated widely in the Irish corporate world, and the media there has seen it, but no news outlet has published it yet.

Judge for yourself. (Don't get all exercised; there's nothing pornographic, it's standard company photos and titles.) Perhaps this will serve as a warning to office-working dudes across the corporate world: Don't do this.