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OpenLearn Live: 19th July 2016

Updated Tuesday, 19th July 2016

Meet the cosmologist trying to plug the gaps in the Big Bang Theory; explore places that are hotter than our current heatwave and discover how BB8 was engineered. Free learning from across the day.

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OpenLearn Live pulls together interesting learning and research from around your world. This page will be updated across the day.

Yesterday, we poked about in gray matter, checked our grammar and looked into Chevening House

See the complete collection of OpenLearn Live

Today's posts

Diabetes patients in hospitals

New research says that the number of patients presenting at hospitals in the UK with diabetes-related conditions is on the rise:

Hospital admissions for a short-term and avoidable complication of diabetes have risen by 39 per cent in the last ten years, a new analysis has concluded.

Almost 80,000 people were admitted to hospital in England for hypoglycaemia – where the blood sugar of a person with diabetes drops to dangerously low levels – for a total of 101,475 episodes between 2005 and 2014, an NIHR-supported study carried out at the Leicester Diabetes Centre found.

The number of admissions for the low blood sugar episodes also known as hypos increased from 7,868 in 2005 to 11,756 in 2010 representing a 49 per cent jump and then 10,977 in 2014, up 39 per cent in ten years.

It represents a 14 per cent hike if the general increase in hospital visits is taken into account, according to the research published in The Lancet Diabetes & Endocrinology journal.

Hospital length of stay, mortality, and one-month readmissions decreased progressively and consistently during the study period.

Professor Kamlesh Khunti, Professor of Primary Care Diabetes & Vascular Medicine at the University of Leicester based at the Leicester Diabetes Centre, who guided the team, said: “Given the continuous rise of diabetes prevalence, ageing population, and costs associated with hypoglycaemia, individual and national initiatives should be implemented to reduce the burden of hospital admissions for hypos.”

Read the full release at The University of Leicester: Rise in avoidable diabetes hospital visits

Explore diabetes with our interactive feature

Making BB-8

It's been, ooh, hours since we posted something about Star Wars, so a quick trip to a galaxy far, far away is overdue. This weekend, there was a huge Star Wars event in London, and during the course of it, the team of engineers who build BB-8 explained the engineering behind him:


There's a write-up of the panel at Wired. Prepare for some daylight to shine upon magic:

Other times, BB-8 was a 'proper' robot, but rarely one with completely autonomous movement. Denon and Lee introduced the 'trike' model - a robot guided by an attached motor unit to control the droid's direction, which was digitally removed from shots in post-production.

In total, seven different BB-8s were used in the filming of The Force Awakens, each with varying levels of puppeteer control. The heat of shooting in the Rub' al Khali desert and the general wear and tear necessitated multiple models, as parts wore out.

Read the full article at Wired: Star Wars' BB-8 is brought to life: Engineers reveal the secrets behind how the droid works

Dip into our Star Wars coverage

Phew, what a scorcher

It's hot. If you like warm weather, you'll be in your element, and the headlines delightedly comparing temperatures in the UK to habitually warm places will be making your day.

The Independent is at it:

Mini-heatwave makes UK hotter than Barcelona, Bangkok and Honolulu

The Croydon Advertiser is at it:

Temperatures in the borough will match those of Portugal, Greece and it will be hotter than Los Angeles.

The South Wales Argus:

Gwent to be hotter than Costa del Sol as heatwave continues

The Newham Recorder:

Newham will be hotter than Mexico City, Rio de Janeiro and Barcelona today with the mercury set to hit 33C

Even Lancashire's 2BR is celebrating the heat:

In Preston temperatures are expected to soar to highs of 31 degrees Celsius, that's hotter than Lisbon in Portugal, whilst temperatures in Blackburn and Burnley will exceed those in Ibiza.

This makes brilliant reading if you're a sun-lover. If, though, you think one of the finest things about Blackburn is that it generally keeps itself at a more pleasant temperature than Ibiza, you might be feeling a bit glum.

So, to put the other side of the story - here's some places that the UK won't be hotter than today...

The UK is cooler than inside a McDonald's Apple Pie

Notably hot - so hot, there's a Facebook page dedicated to the hot pie. 

If you want to be precise, the temperature of a McDonalds Apple Pie will be determined by the temperature of the UHC - the Universal Holding Cabinet - where the cooked pies are stored. According to McDonalds, there are pretty hot places:

 The UHC has two different temperature settings. One for breakfast and one for the main menu. The breakfast temperature is 79C and the main menu is 93C.

There's actually some science behind why the inside of an apple pie - whether made by McDonalds, or a props person working on a straight-to-DVD sequel to American Pie - feels so much hotter inside than the pastry casing would have you expect. Physlink explains:

There are 2 principles behind this: thermal conductivity and specific heat capacity. 

Thermal conductivity is just the measure of how quickly heat energy travels through a substance. The pastry contains many pockets of air and cannot transport energy from a few microns away from your tongue to the interface with your tongue efficiently. Thus, as the outermost layer comes to equilibrium with your relatively cool mouth, more heat has a hard time rushing to the surface and flowing into your flesh where your nerves can sense it. 

Specific heat capacity is something like energy density of a substance, and measures how much energy must be contained in a substance for it to have a certain temperature. For example, 100 grams of aluminum at 100 degrees C has more heat in it than 100 grams of copper at the same temperature. If you dropped both pieces of metal into separate cups of water, the one with the aluminum chunk will get warmer than the other- there's just more energy contained in it. Since the filling is mostly made of water, and water has a very high specific heat, the filling must give off a lot of heat for its temperature to decrease. This has 2 effects: when the pie comes out of the oven, the filling cools down much more slowly, and as a fragment of filling gives up heat to your tongue, it only cools down a tiny bit. 

The UK is cooler than a volcano's lava-filled cone

Generally, lava inside a volcano is somewhere between 700 & 1,200 degrees, says Universe Today.

If you want to know what's going on inside a volcano, a great place to start would be this pair of videos by the OU's Dave Rothery - where he talks about the dangers of ash clouds, and what will happen when the supervolcano in Yellowstone blows.

And talking of Yellowstone...

The UK is cooler than Yellowstone's geothermal waters

Because Yellowstone National Park in America is quite a way above sea level, it has a lower boiling point for water than the one you learned in school - 93 degrees celsius. (If you're wondering why, StackExchange considered this question a short while ago). And a lot of water in the park reaches that, and higher temperatures - which is why the famous geysers break surface all across the basin.

So the water around Yellowstone (heated by volcanic activity) is hot. Very hot. In fact, it's dangerously hot, as the Parks Service warns:

In June 2006, a six-year-old Utah boy suffered serious burns after he slipped on a wet boardwalk in the Old Faithful area. The boy fell into hot water that had erupted from nearby West Triplet Geyser. He survived, but 20 park visitors have died, the most recent in 2000, scalded by boiling Yellowstone waters as hot as 250 degrees Fahrenheit.

“Geothermal attractions are one of the most dangerous natural features in Yellowstone, but I don’t sense that awareness in either visitors or employees,” says Hank Heasler, the park’s principle geologist. The National Park Service publishes warnings, posts signs, and maintains boardwalks where people can walk to get close to popular geyser fields. Yet every year, rangers rescue one or two visitors, frequently small children, who fall from boardwalks or wander off designated paths and punch their feet through thin earthen crust into boiling water.

The UK is cooler than a kangaroo rat

Kangaroo Rats are, under normal circumstances, about a degree warmer than an average person - 38 degrees. Their way of coping with the heat of their home terriitory is pretty, well, cool - as Biotopics explains:

It is said that whilst underground in their cool humid burrows (where they spend the majority of their time), kangaroo rats retain as much water as possible by effectively recycling water which would otherwise be lost in their breath.

Air with a high water vapour content leaves the lungs - the unavoidable consequence of exposing a relatively large surface area for the absorption of oxygen. Therefore air which is exhaled has a very high relative humidity - close to 100 per cent saturation, and it is also at core body temperature - 38°C. 

If the temperature of the kangaroo rat's nasal passage is any cooler than 38°C due to the cooler external environment, then water will condense before leaving the animal. The liquid water can then be reabsorbed, possibly by osmosis into the blood, or by being simply swallowed. It is also said that the stored seeds absorb water from the air - possibly originating from the kangaroo rat’s breath - or from the soil of the burrow. This results in greater water conservation (less water loss) than other mammals of a similar size. 

Conversely it is said that the nasal passages may have a role in controlling the kangaroo rat's body temperature. In the brief periods when the animal is active above ground and breathing in air with a lower humidity, water will evaporate from the nasal passages, causing cooling of this area which is not far from the brain. This could cause a cooling effect of up to 5°C. This allows the kangaroo rat to be active, for example foraging for food and moving to avoid predators so they are not restricted to staying in the burrow. 

Some kangaroo rats, it's believed, never need to drink water at all.

The UK is cooler than the inside of a star, except for one place in Oxford

Janet Sumner of The Open University took a trip to a warehouse in Oxfordshire to watch a star being made in a lab. And that was a hot star:

A 10 metre cubed doughnut of plasma with a staggering temperature of tens of million degrees centigrade! It might not be as big as, but it is hotter than, the sun – our nearest star.

You can read about Janet's star  - and watch it being born - here on OpenLearn.

Happy birthday: Jayant Narlikar

We're putting the focus on people celebrating their birthdays this week. Yesterday, we started with mycologist Paul Stamets. Today, we're meeting Jayant Narlikar.

Jayant Narlikar Creative commons image Icon Biswarup Ganguly under Creative Commons BY 4.0 license

Born on July 19th 1938, Jayant Narlikar is India's foremost cosmologist. His most famous work has been - alongside Fred Hoyle and Geoffrey Burbridge - to move beyond the idea of The Big Bang Theory. In Narlikar's view, there was no big bang that kick-started the universe - the Hoyle-Narlikar theory suggests that the universe is more like an oscilating pendulum, expanding, then contracting, then expanding again. A series of mini-bangs.

Why does Narlikar reject the Big Bang Theory? As he told NCBS news, it's because the maths don't add up:

When you claim that the universe started in this particular way you are making a very profound statement. If I make a statement saying that the sun started in a certain way, I would immediately be asked for proof that the sun started in that way. I will have to go around gathering evidence of solar systems forming, stars forming. I will have to produce evidence saying that this is how new solar systems are being formed, so the sun must have been formed in the same manner. That is a reasonably credible assumption.

Now with the big bang there is only one event that happened. So like the sun you can’t say that there are other big bangs going on that are what ours was like. The second problem is that at the big bang mathematics and physics break down. So there is no way of mathematically describing it. That is not a satisfactorily scientific approach, to ascribe something to speculations which you cannot justify using mathematics and physics.

As well as writing widely on science, Jayant is also known for his fiction. He writes - perhaps unsurprisingly - science fiction, but he's no more prepared to accept a weak piece of science fiction as he is a poorly evidenced piece of science research. In a Biblio interview, he lashed out at sci-fi that isn't particularly scientific:

“There is so much trash going under this genre with horror, black magic and fairytales essentially hijacking the true sprit of science fiction. This demeaning feature is reflected in the Indian version also, though to a lesser extent.”

He also has another claim to fame: he's beaten Stephen Hawking at table tennis:

He was still an undergraduate, one year behind me, but at Oxford. He joined Cambridge after graduating from Oxford. At the end of the five or six week course all the students had organized a table-tennis tournament. In the final I was playing Hawking. I beat him, but he was very normal, that’s the point I am trying to make.

Here's an interview from Indian television last year, where Jayant talked about his life and work.


Try our free course on the Big Bang

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