STARDATE Friday 14th November 2008 Issue 295
Hoorah! We can all breathe a sigh of relief as wonky veg make a comeback. Yes, no more perfectly straight cucumbers, evenly sized and shaped toms and pristine parsnips. Let’s hear it for leggy carrots and knobbly spuds! EU regulations governing the acceptable size and shape of our fruit and veg are due to change. And not before time. After all, none of us are perfect. Except for Planet Science naturally.
- Planet Pick of the Week – Myths & Minefields
- Gimme Five – Facts about MRI
- Planet Super Powers
- Activity of the Week – Eyeball Bubble
- Mouses at the Ready – November Flipsides
- Noticeboard – FYI
- Recommended Websites of the Week
- The Winners’ Enclosure
- Joke of the Week
1. Planet Pick of the Week
Myths & Minefields
Introducing, all the way from the mists of ancient time, Myths and Minefields for age group 10 - 12.
New on Planet Science this week, if you’ve ever been captivated by the gruesome and visceral Greek creation myths then prepare for a treat. We’ve had top storytellers Hugh Lupton and Daniel Morden captured in sound, plus some weird and wonderful visuals to go with the stories.
The stories are great in themselves, but also throw up science ethics related questions in each episode, a perfect excuse for a discussion or debate.
This content is designed to offer an introduction to the sorts of debates that will take place in ‘science and society’ type lessons in your students’ later school careers, and as informed adults.
Find out more about Myths and Minefields
2. Gimme Five
Facts about MRI
- A magnetic resonance imaging (MRI) scanner can build up detailed 3D pictures of organs inside the body.
- Felix Bloch and Edward Purcell received the Nobel Prize in 1952 for discovering magnetic resonance.
- The human body is approximately 63% hydrogen atoms.
- An MRI machine produces a magnetic field between 5,000 and 20,000 gauss (10,000 gauss = 1 tesla). The Earth has a magnetic field of 0.5-gauss magnetic field.
- The magnetism in an MRI is strong enough to cause scalpels, watches and even beds to fly across a room into its massive field.
Find out more about MRI
3. Planet Super Powers
WHOOSH! This week I'd like to introduce someone who is here one second and gone the next. No he's not invisible ... he's Jay Garrick ... The Flash!
The Flash
He's been called the fastest man alive and nicknamed the Scarlet Speedster. But are his amazingly fast reflexes and ability to run at superhuman speed purely comic fiction defying the laws of physics?
We know that average speed = distance/time. Usain Bolt, currently the fastest human in the world, broke the 100 m world record when he finished in 9.69 s that's an incredible 10.32 m/s - about 23 miles per hour (mph) - and he broke the 200m world record finishing in 19.30 s (10.36 m/s). He's incredibly fast, but not as fast as the Flash who travels at the speed of light. How fast is that? Work it out yourself with this mallowtastic Planet Science experiment.
Could a human travel over land at superhuman speeds?
Running at high speed burns some amount of calories and requires a lot of oxygen. Over time the muscles slow down when oxygen is used up faster than it is supplied and waste products (carbon dioxide and lactic acid) build up in the muscle tissue. If you're thinking of travelling at superhuman speeds you'll need invent something to give you that extra oomph!
ZIP! In 1997 the ThrustSSC travelled faster than the speed of sound (about 330 m/s or 760 mph) reaching 763 mph and a British team working on the BLOODHOUND project are attempting to achieve 1000 mph.
Want to improve your performance?
Quick Heal Neil (invented by pupils at Battlefield Primary School) has adrenaline boost buttons. Adrenaline increases the heart rate and prepares us to fight or run known as the 'fight or flight' response. The increase in heart rate speeds up the supply of oxygen and glucose to the brain and muscles which can then work harder than you'd ever thought possible!
With all that speeding around you're going to need some protection....
The Flash had a metal helmet with wings to protect his head but personally I'd opt for something covering the whole body. What about an exoskeleton made of Hybrix stainless steel? Strong but light it wouldn't be the extra weight that slows you down.
Visit our new pages www.planet-science.com/PSP for more about designing characters and super powers!
Thanks Elsa! See you next week.
4. Activity of the Week
Eye Bubble
You will need:
- Bubble solution - washing up liquid with some water in a ratio of about 1:1 will make reasonably strong bubbles
- A black bin bag
- Masking tape
- A straw
- A large white lampshade, conical if possible, and preferably without metal attachments. It will get damp so don't use a good one
- A table somewhere bright
What you do
- Cut a large square out of the black bin bag, larger than the base of the lampshade and tape it to the table (don't use a good table for this experiment).
- Pour a little bubble mixture in the middle of the square and use your straw to blow a bubble. If your bubble keeps bursting try adjusting the amount of water in your bubble mixture and make sure your black bag is smooth and flat.Turn on the microwave for a maximum of 4 seconds.
- Place your lampshade over the bubble and look down. Watch as the pupil of your bubble eye slowly dilates...
What's going on?
Light is carried in waves, and just like water waves they can combine to make much bigger waves when the crests coincide, or will cancel each other out when a wave crest coincides (or is 'in step with') with a wave trough. This is called, respectively, constructive and destructive interference.
A bubble is a thin curved sheet of water and detergent and has two surfaces, its outside and its inside. Light reflects off the bubble in the same way that light reflects off a window: any light hitting the bubble will be split; some will reflect off the outside surface, some will reflect off the inside surface, and the rest will pass straight through.
Light reflects differently when passing from air to water than from water to air. From air to water - as in a reflection from the outer surface of the bubble - the light wave is completely reversed: a trough becomes a crest in the reflection, and vice versa. From water to air - as in a reflection from the inner surface of the bubble - the crests remain crests and the troughs remain troughs. If there was nothing else going on, these two reflected waves - one from the inner surface and one from the outer surface - would completely cancel each other out.
However, there is more to it than that. Any light reflecting off the inner surface of a bubble will have travelled slightly further than light reflecting off the outer surface of the bubble. This slight difference in path length puts the two reflected waves out of step. White light is made up of a spectrum of different colours all with different wavelengths, and if the waves are out of step by one of these wavelengths then that particular wave and colour will be cancelled out (destructive interference). This means that the light will not appear white, but will be coloured by those waves which have escaped the destructive interference.
All this means that the thickness of the bubble, which affects the path length of the two reflected waves, determines the colour we see. For thicker, newer bubbles the difference in path length is long, and long wavelengths are cancelled out - leaving the bubble looking blue-green. As the bubble gets thinner the green and yellow part of the spectrum is cancelled out and the bubble starts to look blue-red. Finally when the bubble is very thin the blue short wavelengths are cancelled and the bubble looks red-yellow. Beyond this the bubble becomes so thin it may burst and the path difference is tiny, all the light is completely cancelled - the bubble appears to not reflect any light at all.
The lampshade provides an even white light surrounding the bubble and the interference of this white light explains why we see the coloured 'iris' of our eye bubble. The pupil is formed and grows as the bubble gets older. Water slowly flows from the top of the bubble towards the table and the bubble thins at the top. This thinning reduces the amount of reflection so the 'pupil' looks black.
This activity came from Planet SciCast
5. Mouses at the Ready
Flipping ‘eck! We’ve got TEN November Flipsides to give away. Why making a Bond movie is harder than it looks plus space dangers and how to beat them.
Would you like to win one? If so then email us with your name and address, and the words ‘NOV-FLIP’ in the subject line, to planet-science.news@nesta.org.uk
The draw will take place at 5pm on Wednesday 19 November.
6. Noticeboard
The Autumn SciCast Quiz
The deadline to send in a film is January 9th 2009 SciCasters! So to get you in the mood here’s 10 questions you’ll get right - if you visit the SciCast site.
If you can get all ten answers correct you'll go into the hat to win the very latest Flip Ultra, the funky little camera that can.
Enter the Camera Quiz now...
Chance to visit Geoscience conference in Vienna April 2009!
'Geosciences Information For Teachers' (GIFT) workshop has places for UK teachers to hear cutting-edge science, related to the Geosciences. These places are generously subsidised by the European Geosciences Union and usually ends up costing UK teachers or their schools nothing. Travel & subsistence grants are available.
Teacher availability is required for 2.5 days in April next year from 19th to 22nd.
For further details visit: www.atmosphere.mpg.de/enid/gift
Closing date: 30 November
National Science Competition
There's a new National Science Competition: www.nationalsciencecompetition.org
This new competition is open to all young people aged 13-19 who have had a significant achievement in science, technology, engineering or maths between 1 September 2007 and 1 November 2008. Young people who have entered another existing competition (Planet Scicast for example) are also eligible to enter this competition with the same activity or project as long as the project took them at least 30 hours. The entry process is open now and the closing date is 28 November 2008. There are significant prizes (£5000 and an international science trip) and media coverage up for grabs.
7. Recommended Website of the Week
Did you know? Sea turtles are one of the longest living groups of animals to have ever existed, having far outlived the Dinosaurs. This week we’re looking at EuroTurtle which is a website dedicated to Mediterranean Sea Turtle Biology & Conservation. It provides information and resources covering all elements of the sea turtle lifecycle; the threats they face; how we can help and learn from these majestic creatures.
Check the United Kingdom Turtle Code and log all your sightings. Plus there’s an interactive ID guide so that you can tell whether you had a near brush with a loggerhead or a leatherback.
In the Environmental Education section you’ll find singalongs, games and stuff to make. Including the impossibly cute Turtle Egg Cartons. Turtley cool eh?
By the way, if you’ve got a good website to recommend then send it along to us
at planet-science.news@nesta.org.uk with RWW in the subject line.
Thank you very gladly.
8. The Winners’ Enclosure
Remember last time when we were offering a two-pack of J.D. Bernal The Sage of Science and Surviving Armageddon? The winner is Gillian Moss of Livingston. Well done Gillian, we hope you enjoy them.
9. Joke of the Week
An enterprising journalist decided to get the scoop of the day by photographing the fearsome phantom that lived in the spooky old mansion house at the edge of town.
When he entered the house, armed with only his camera, the ghost descended upon him, moaning and wailing and clanking chains.
“I mean no harm; I just want your photograph,” the journalist said bravely.
Pleased at this chance to make headlines, the ghost posed for a number of shots, and the happy journalist rushed back to his darkroom and began developing the photos.
Unfortunately, they turned out to be so underexposed that nothing could be seen in them.
He was distraught, and went to a local pub to drown his sorrows. Meeting his friends there, they asked what was wrong. Not wanting to tell the whole story, he simply explained with a single sentence: ......
“The spirit was willing, but the flash was weak.”
Have a great week!
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