The Story of Electricity (Part One)

We have been looking at the history of electricity for this blog post, and by co-incidence, this has been the subject of a documentary series on BBC Four called “Shock and Awe: The Story of Electricity”

It was always known from historic times that certain substances such as amber could be rubbed and would attract small items, like feathers. The Greek word for amber is “electron” from which the word electricity comes. In the 17th Century, scientists started to experiment with electricty, and to help with these experiments, Otto von Guericke created the first reliable device that could generate static electricity. This was a globe (made out of sulphur) that could be rubbed by hand.

Benjamin Franklin (1706-1790) was a scientist and politician who was one of the founding fathers of the United States. Benjamin conducted experiments on a number of scientific areas, including electricity, but he was most famous for his experiment with a kite in 1752, when he fastened a metal key to the bottom of a kite string and flew it during the build up to an electrical storm.

When he found that sparks were jumping from the key onto his hand, it proved to him that lightning was a form of electricity and this led to the invention of the lightning conductor that you see on many buildings.

Artists impression of Benjamin Franklin's Kite experiment

Italian anatomy professor Luigi Galvani (1737-1798) experimented with electricity in 1771 by fastening the legs of a frog to a copper hook and attached the hook to an iron railing. The frog’s legs twitched violently, and he mistakenly concluded that the muscles of the frog must contain electricity!

Alessandro Volta (1745 – 1827) looked at Galvini’s work with a frog and realised that the frog’s legs were twitching as they were conducting electricity between the copper and the iron. This started a rivalry between the two scientist, and it inspired Volta to create the first battery using zinc and copper, similar to Galvini’s test, to show that electricity did not come from the frog’s legs!

You can make a battery like Volta’s using a lemon! To make this, squeeze the lemon, to get the juice moving, put a piece of copper (or even a copper coin) and a piece of zinc into the lemon, and attach these by pieces of wire to a LED (light), and hey presto! The light should come on!

A battery made from lemons

A battery made from lemons

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Hurricane warning!

Palm trees being blown by a tropical rain storm

We’ve all seen spiralling cartoon and movie hurricanes sending up animals, cars and heavy objects flying, but how do these phenomena actually start?

Hurricanes form off the coast of Africa when warm, moist air rises from the sea and meets cooler air and condenses into storm clouds. This makes room for more warm air from the sea and leads to a spiralling effect, sucking up more air and getting hotter and bigger as it starts to move across the ocean.

Right in the middle is the eye which stays relatively calm. If children want to know what the eye looks like, they can try a small experiment: at a sink, fill it half up with water, then pull the plug. The water will start to rotate around, and a hollow of air will form in the middle of the swirling water. That’s like the eye, and it’s a similar way that the hurricanes spiral round.

Storm warning sign

Storm warning sign

Some places, such as North and Central America and countries around the Pacific, are at risk from hurricanes during part of the year. Only this year, Hurricane Isaac caused severe flooding in Louisiana where thousands of residents had to evacuate their homes. For the people that live there, this means that a lot of time is spent tracking hurricanes, and if a hurricane or tropical storm is approaching, they need to board up their homes, get food and water supplies in to ride out the storm. Sometimes they may even have to evacuate to a safer area.

Britain is pretty safe from tropical weather because hurricanes normally lose their strength by the time they reach our shores. But sometimes we feel the after effects. In 1987, weather reporter Michael Fish infamously said to a caller to the BBC who reported an approaching hurricane, telling his viewers, ‘Don’t worry, there isn’t, but having said that, actually, the weather will become very windy.’ It was the worst storm in 300 years.

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Mars Curiosity Rover

After all the excitement of London 2012 has come a thrilling scientific event – the landing and exploration of the Mars Science Laboratory a.k.a. Curiosity Rover on planet Mars.

Mars Curosity Rover, Image Credit: NASA/JPL-Caltech

Image Credit: NASA/JPL-Caltech

The landing itself seemed impossible. NASA called it “Seven minutes of terror” as the spacecraft carrying Curiosity (which is the size of a small car) had to perform a series of complex turns using thrusters and discarding weights to guide it above the landing spot on the Gale crater. It then deployed a parachute and used retro rockets to slow itself down, before lowering Curiosity on ropes to the surface and having the spacecraft crash. And all this without any control from back on Earth!

As we know now, it did land successfully and has started to send back photos of the Mars landscape and examine nearby rocks. Soon it will start to live up to it’s roving name and start to move over the planet.

The Curiosity rover has been sent to Mars to find out about the type of soil and rocks (the geology) and about the climate on the planet. Mars is the nearest plant in the solar system to Earth and it is the and most like us. So studying Mars helps scientist to find out more about Earth and the rest of the Solar System.

Mars Curisoity is also looking for evidence of life on Mars. By this, scientists mean primitive forms of life, which could form, or could have formed, the basis of cells and life forms and not Martian people hiding in caves!

There has long been popular speculation that Mars has been inhabited by other life forms. As soon as people started looking at Mars with telescopes, they could see it had seasons and polar ice caps that shrunk and grew with the seasons. At the end of the 19th century, scientists studying Mars thought they could see canals (now thought to be streaks of dust), and these had been produced by past civilizations.

Martian channels depicted by Percival Lowell

Martian channels depicted by Percival Lowell

This gave HG Wells the idea of writing “The War of the Worlds” about an invasion from Martians fleeing their planet. War of the Worlds was broadcast in the form of a radio documentary in New York in the 1930’s and famously people thought it was happending for real and ran out in the street in fear of their lives!

By sending unmanned spacecraft to Mars, it helps pave the way for a possible manned mission to Mars. This has been talked about since the 1950’s, and particularly after the successful Moon landings between 1969 and 1972,  but with budget cuts everywhere, it looks unlikely for the near future – and scientists can learn a lot from unmanned flights like this one.

Resources

NASA’s page on the Mars Science Laboratory Mission, with images and interactive activities
http://marsprogram.jpl.nasa.gov/msl/

Latest news and photos from NASA
http://www.nasa.gov/mission_pages/msl/index.html

Let’s Go to Mars. NASA Simulation of a Mission to Mars where you need to decide which items to take
http://spaceplace.nasa.gov/mars-adventure/redirected/

Interactive photo describing the Curiosity Rover
http://mars.jpl.nasa.gov/msl/multimedia/interactives/learncuriosity/index-2.html

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Hayfever

Wimbledon’s just finished, the sun has finally come out, the school year is winding down, and here at Storm we’ve even been out on the hammock.

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But summer isn’t all fun, as a lot of people suffer from hay fever. This means runny noses, itchy eyes and a lot of sneezing. Aitchoo!

Although the flowers look lovely at this time of year, they are the cause of this discomfort, along with grasses and some trees. Why? Because spring and summer is the time for pollination. This is where the pollen on the male part of the plant (the stamen) lands on the female part (the stigma) in order to fertilise it. Sometimes plants can pollinate themselves, but stronger plants are produced when the pollen of one plant is transferred to another.

But how does it get there? Well, sometimes bees carry the pollen from one plant to another. So when you spot a bee this summer, it’s possible that it’s off to pollinate a plant. But the wind also carries the pollen, and so the air is full of it in summer.

If someone suffers from hay fever, it’s because they’re allergic to pollen. So when they breathe a load of it in, it can make them sneeze and generally feel rubbish. Luckily, the pollination season doesn’t last very long and sufferers can take medication to help them.

So next time you look out the window this summer, imagine all the tiny pollen in the air. And if you suffer from hayfever, remember it’s not long until summers’s over!

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From Life Cycle of Plants, one of the activities in Science by Storm

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Magnets

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Human body

To be continued…

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Transit of Venus

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Shadow Puppets

More to follow.

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Growing Cress

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Urban foxes

How animals adapt.

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