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- British engineers: Beryl Platt
- Armistice Day
- New free course: Drinking water
- Fish poo as fertilizer
- Tonight, BBC Four, 9pm: Colour
- Tonight, BBC Four, 10pm: Richard Hammond's Wild Weather
- Where do leaves come from?
Work in the OpenLearn offices was interrupted this morning as - outside the windows - men with large machines attempted to blow leaves into neat piles. If you stop to think about it, it's astonishing how all these leaves have appeared over the course of the year. As if they emerge from thin air. Which, as The 'Scope blog explains, is exactly what they do:
Plants take carbon dioxide from the air, and using the energy of sunlight, turn it into carbohydrates – this is photosynthesis. But they don’t just use the carbs for energy. The sugars are the carbon basis for synthesizing every biomolecule the plant will need in order to build leaves and wood.
We have covered carbon (from CO2), hydrogen (from rain and metabolic water), oxygen (from carbon dioxide and metabolic water), but what about the nitrogen in DNA and proteins? Believe it or not, that comes from the air too.
N2 in the air is hard to tear apart so the nitrogen can be used in building biomolecules. Plants can “fix” carbon themselves, turning gaseous carbon to solid carbon during photosynthesis, but they can’t fix nitrogen. To turn nitrogen into a form they can use, plants rely on nitrogen fixing bacteria in the soil.
Many plants form a symbiotic relationship with nitrogen fixing bacteria, letting them live inside nodules of their roots. Therefore, the nitrogen the trees use comes from the air, even if it passes through the bacteria first.
Richard Hammond's guide to how extreme weather shapes the world continues tonight, with water coming into focus. (Today has been about water in lots of ways, it turns out.) Amongst the experiments Richard tries, he'll see what happens when you drop one year's worth of rain on a car. And what happens is something like this:
In the second programme in our series exploring the many millions of colours around our planet - and the stories behind them - Helen Czerski explores living, breathing colours. In the course of the hour, she'll have an encounter with a peacock:
Want more peacock videos? Jimmy Doherty discovers what we can learn from peacock feathers
If you ever kept a goldfish as a child, you'll probably have spent some time watching as a coil of fish poo emerged from the creature. But could there be use for fish poo beyond making a kid go "ewwww?" Actually, yes - new research is exploring how aquaponics can use the waste from fish to grow vegetables sustainably:
It begins with fish poo and pee, both of which contain lots of ammonia. Worms that live in rooting substrates break the solids down and then bacteria convert the ammonia into nitrate, which acts as a fertiliser. The plants absorb the nitrate and effectively filter the water for the fish. By which point the fish will once again need the toilet, and so on. It’s a virtuous circle.
The result is high-density food production that works equally well at home or in large industrial warehouses. It’s suitable in urban spaces or on land suffering from drought, pollution or soil depletion that is otherwise difficult to farm. It produces both fish and vegetables, reducing the load on our over-exploited and polluted oceans.
Water. There it is, in the tap, cascading out, ready for you to swig by the glass. But what's it made of? What's it made of chemically, more specifically? Yes, yes, H2O of course, but there's more to your drinking water than that. That's what our new free course is about:
Drinking water contains a mixture of anions and cations which are monitored and managed to avoid adverse health or environmental effects.
The toxicity of a chemical to a receptor can be illustrated by a dose–response curve.
The LD50 is the lethal dose responsible for killing 50% of the receptor population. The LC50 is the analogous lethal concentration.
Toxicological effects observed in the short-term are termed acute while chronic effects arise from prolonged exposure.
The lethal dose low (LDLO) is the lowest dose per unit of body weight of a chemical known to have produced death in a particular receptor.
Tolerable daily intake or guideline values are often set for chemicals in drinking water.
Today is the day the nation pauses to remember those who died in conflicts around the world. The 11th November is chosen because that was the day the guns of the First World War fell silent. However, as the team who made the BBC/OU Timewatch programme The Last Day Of World War one found out, even after the agreement to end the fighting was struck, the killing continued until the last minute. Our videos, presented by Michael Palin, explain more.
This week, to mark what would have been George Jennings' birthday, we're celebrating with some short profiles of extraordinary British engineers. Yesterday, we met Christian Galloway, who helped open up Canadian coalfields. Today's engineering hero is Beryl Platt, née Myatt, latterly Baroness Platt of Writtle.
Beryl was born in Leigh-On-Sea in 1923. During the early years of the war, she found herself at Cambridge intending to read mathematics, but a £25 a week state bursary intended to encourage students to take up engineering persuaded her to switch courses. She was one of just five women studying what was then called Mechanical Sciences at Girton and, despite having the course crammed into two instead of three years, Beryl successfully completed her studies. Normally, this would mean that she got a degree, except she was a woman, and at this point Cambridge didn't award degrees to women, instead patting them on the head and giving them a "title of degree". In the middle of the 20th Century. (In 1948, these titles were converted to the proper degrees the women had actually earned.)
She was advised by CP Snow on graduation to take a role which would help the war effort, so she joined the Hawker aircraft company. Earning three pounds a week, and working in a mostly male environment, Beryl started testing and assisting with the production of the range of Hawker planes being used by the RAF. She took a leading role, but - as recorded in her Telegraph obituary - she was not always accorded the respect her skills demanded:
“People would ring up and say 'I want to know the cylinder head temperature of the Centaurus engine’. I’d rattle them off. There would be a deathly hush at the other end of the line and then they’d say, 'How do you know?’ They assumed that if you were a woman you couldn’t be an engineer.”
When the war ended, despite being offered a role a Hawker, she chose to join British European Airways to work on civil aircraft. Her speciality was plane safety, modelling - for example - how a plane could land safely if engines failed over mountainous terrain.
In 1949, she married Stewart Platt which meant her career as an engineer came to an end - although she never stopped being an engineer at heart, carrying a screwdriver with her everywhere she went.
Beryl went on to have a second career, in politics. She became chair of Essex council in 1971; from 1983 she chaired the Equal Opportunities Commission. An apt choice, considering how she had forged an engineering career at a time when it was a nearly all-male domain.
When she was made a Baroness and joined the House of Lords in 1981, she included a nod to her start on her coat of arms - a cog wheel sat at the heart of the heraldic design.
Baroness Platt died on February 1st, 2015.