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OpenLearn Live: 30th November 2016

Updated Wednesday 30th November 2016

Look, we're calling them ice unicorns. What makes ice spikes happen? Plus Obama's record on climate change considered, and how the Big Mac was born. Learning and research across the day.

OpenLearn Live does the hard work of picking the interesting bits of learning and research from around the web, so you don't have to. This page will be updated across the day.

Yesterday: online cheats, and a pioneer aviation daredevil

On this day last year: the first Mongolian in space, and remaking Heathrow

See the complete collection of OpenLearn Live

Today's posts

Death of a hamburger salesman

The biggest Big Mac, an exhibit at the Big Mac museum Creative commons image Icon Via Tsuji under Creative Commons BY-NC-ND 4.0 license The biggest Big Mac in the world, a centerpiece of a museum dedicated to the sandwich The death has been announced of Michael 'Jim' Delligatti, the architect of cultural icon/health bogeyman. Delligatti was the McDonalds franchise holder who came up with the Big Mac. Penn Live reports:

James Delligatti, the Pittsburgh-area McDonald's franchisee who created the Big Mac nearly 50 years ago, has died, the Associated Press reports. He was 98, and died at home surrounded by his family on Monday night.

Delligatti's franchise was based in Uniontown, about 40 miles south of Pittsburgh. While there, he invented the chain's signature burger with two all-beef patties, "special sauce," lettuce, cheese, pickles, onions on a sesame seed bun. 

It's an interesting reverse situation - usually the franchisee is reliant on the central company creating and sharing key products. And, as a 2009 piece for the Pennsylvania Center For The Book records, McDonalds as a corporation weren't initially keen on supporting what would become the company's signature product:

One of Delligatti’s obstacles in getting the Big Mac approved for sale was its proposed price of 45 cents—twice that of a regular cheeseburger. It took the support of Ralph Lanphar, a regional manager in Columbus, to obtain corporate permission to test the Big Mac. This permission was limited—Delligatti could only test the sandwich at his Uniontown store, and he was told he had to use the standard McDonald’s bun. When this bun proved far too small for all the contents of the Big Mac, Delligatti ignored management’s requests and ordered a larger, three-piece bun. Within a few months, the new Big Mac was increasing the Uniontown store’s sales by better than 12 percent. The sandwich was a hit.

Due to the success in the Uniontown store, the Big Mac was soon sold in all of Delligatti’s stores. When each of these stores showed significant gains, McDonald’s managers and franchise owners elsewhere looked to Delligatti and his stores for information on his new sandwich. The McDonald’s chain added the Big Mac to other test markets, and when all of them scored 10 percent or better in sales gains, the new product was finally put into nationwide distribution in 1968. It had taken Delligatti nearly two years to the sell the company on the idea.

The idea wasn't entirely novel, either - the double-burger-in-a-bun model was lifted from the rival Big Boy franchise.

Watch the OU's Dev Kodwani explain why McDonalds shapes itself to fit local markets

How did Obama do on the environment?

It will soon be time for Obama to hand over the keys to the White House to Donald Trump. And along with those, and the wifi password, Obama will be handing over stewardship of one of the world's largest economies and the connected impact on the planet. It remains to be seen how Trump rises to that challenge, but we're now in a position to mark what Obama achieved. A team from Colombia University, working with The Guardian, files this mixed report card:

Explore climate change with Creative Climate

What can we expect from President Trump?

St Andrew's Day

Today is St Andrew's Day. Find out more about patron Saint of Scotland in our St Andrew's collection.

The lottery breached

The National Lottery has discovered that some of its online players have been hacked. BBC News reports:

About 26,500 National Lottery accounts are feared to have been hacked, according to its operator Camelot.

The firm said it did not believe its own systems had been compromised, but rather that the players' login details had been stolen from elsewhere.

The company said that no money had been taken from or added to the compromised accounts.

But it added that there had been other suspicious activity on fewer than 50 of them.

So the odds are against your account having had suspicious activity upon it - although, given Camelot's business is persuading people that long adds against something shouldn't make you think it won't happen, that may or may not be reassuring.

Perhaps this is a good time to think about your online security, and toughen up your passwords. 

Maybe you've been putting off doing that because it's a faff to keep track of secure passwords. We might have an answer, though.

Find out about how password managers can make you more secure, more easily

Ice pack: Ice spikes

This week, we're starting off each day with an exploration of the wonderful world of frozen water. Yesterday, we inspected some rabbit frost. Today: ice spikes.

Ice spikes Creative commons image Icon Erik Wilde under Creative Commons BY-SA 4.0 license

For the life of us, we can't understand why these things aren't known as ice unicorns. Yesterday, there were no end of whimsical names for the ice formation. Today, though, just ice spikes.

You'll have spotted that while so far this week we've had to go outside to spot the ice feature, today, we're firmly indoors. And opening our ice-making tray in our freezers. Sometimes, the cubes are cubes. Some people, though, get cubes with little horns on them.

How come? There's a short explanation as to why from the University of Toronto:

The short explanation is this: as the ice freezes fast under supercooled conditions, the surface can get covered except for a small hole. Water expands when it freezes. As freezing continues, the expanding ice under the surface forces the remaining water up through the hole and it freezes around the edge forming a hollow spike. Eventually, the whole thing freezes and the spike is left.

If you want a slightly longer explanation, they have one of those, too:

 the form of the ice crystals depends on the cooling rate and hence on the degree of supercooling. Large supercooling favors sheets which rapidly cover the surface, with some sheets hanging down into the water like curtains. These crystallites tend to join at 60 degrees and leave triangular holes in the surface. Hence, spikes often have a triangular base. The sides of the spike are sometimes a continuation of pre-existing subsurface crystallites, and can extend from the surface at steep angles.

If you want a really, really long explanation, the California Insititute of Technology's K. G. Libbrecht and K. Lui published a paper exploring the phenomenon:

We have investigated the formation of 10-50 mm long “ice spikes” that sometimes appear on the free surface of water when it solidifies. By freezing water under different conditions, we measured the probability of ice spike formation as a function of: 1) the air temperature in the freezing chamber, 2) air motion in the freezing chamber (which promotes evaporative cooling), 3) the quantity of dissolved salts in the water, and 4) the size, shape, and composing material of the freezing vessel. We found that the probability of ice spike formation is greatest when the air temperature is near -7 C, the water is pure, and the air in the freezing chamber is moving. Even small quantities of dissolved solids greatly reduce the probability of ice spike formation. Under optimal conditions, approximately half the ice cubes in an ordinary ice cube tray will form ice spikes.

There's a further seven pages. But you probably get the drift.

If you'd rather watch, here's a video explaining what's going on:

Want to experience more weather without going outside? Try our wild weather experiments





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