Science to save your life!

Picture the scene – you're laid out on a raft, the sun is beating down, your mouth feels like the bottom of a birdcage. "Water! Water!" you gasp through parched lips. The seawater surrounding you mocks back "Hah! Try drinking this matey and you'll know about it!"
But wait! What's this? You managed to grab a large bowl, clingfilm, sticky tape, a glass and a small rock before the ship sank (!). Thank goodness for that! Now all you need is to make a solar still…

You will need:

• large bowl


• short glass or cup


• plastic wrap


• small rock


• pitcher of water


• salt


• long spoon for stirring

What to do:

First make saltwater by adding salt to fresh water. Stir the water until the salt dissolves. Now pour about two inches of saltwater in a large bowl. Take an empty glass and put it in the bowl. The top of the glass should be shorter than the top of the bowl, but higher than the saltwater. Put clingfilm over the top of the bowl. You may need to use tape to make sure the seal is tight. The last step is to put something heavy right in the centre of the clingfilm, over the empty glass. That will weigh the plastic down and help you collect the water. Now you've made a solar still. It's called a still because it distills, or purifies, water. Leave your still outside in the sun. Leave it alone for a few hours, or even a whole day. The longer you leave it out, the more water you'll collect. When you're ready to check your still, take the plastic wrap off and look at the water that's collected in the cup. Do you think it's salty or fresh? Taste it – it's fresh! (make sure all the items are cleaned thotoughly before you try this experiment though!)

What's going on?

Rays from the sun heat up the salty water in the bowl. When the water gets warm, it evaporates and becomes a gas. When the gas rises and hits the clingfilm, it turns back into water droplets. Eventually, gravity makes the water droplets roll down the clingfilm towards the rock. Then the water droplets slide off the clingfilm into the glass. The salt doesn't evaporate, so it gets left behind in the bowl. Water evaporates in the same way from lakes, rivers, and oceans. The water heats up, turns into a gas, and then condenses to fall back down as rain. Now, can you distill fresh water from other liquids like cola or orange juice?

Did you know?

This can also be done with urine if you're in the desert and water is hard to come by. If you do not have a pot, you can just dig a hole in the ground, do your business in the hole, place a glass/container in the middle and cover with something (plastic bag works). The natural heat of the sand will evaporate the clean water into the glass. You never know, it may save your life!

Egg Engraving

This is like engraving in reverse i.e. your name will stand out in relief from the shell rather than be etched into it.

You will need:

• Hard boiled egg
• Wax crayon
• White vinegar
• Large glass or bowl (big enough to hold the egg)
  

What to do:

Ask an adult to hard boil an egg for you. Print your initials or your first name, large and fairly thick, on the shell of a hard boiled egg with the wax crayon. Now put the egg in a glass large enough to hold it and add enough fresh white vinegar to cover it. Tiny bubbles should form on the egg which show that the acid in the vinegar is reacting with the shell. The shell under the waxy letters is protected from this acid action. In an hour or two, when the bubbling stops, replace the now neutralized vinegar with a fresh supply. After another two hours wash off the egg under running water. Rub your fingers over the letters and they should stand out in relief. You can even try to GENTLY remove the wax coating with a soft brush and scouring powder under running water.

What's going on?

An average eggshell is 2.35mm thick. It's made of 3.5% protein, 1.5% water, and 95% calcium carbonate mineral. It is this mineral that reacts with the acetic acid in vinegar. The wax protects the shell from coming into contact with the vinegar. If half of the shell has dissolved during the four hours, then it has only about a 1.25mm thickness left. So be careful!

How good are your vectors?

Warning: do not play this game if you are easily offended

Energy for the Future lecture

Mr Anders Ihle from ECC Care Thailand came to present an Environmental Technologies for the Future lecture as part of the Science and Technology Week. Click on the image above to watch the talk, or download the podcast below to listen to it. His powerpoint is also available on a link below. Thanks to Mr Ihle for his highly entertaining and informative lecture. If you have any questions for him you can email him at andersihle@yahoo.com

Right click here, "save target as" to download the podcast (98MB *.mp3)

Rick click here, "save target as" to download the powerpoint used in the lecture (14MB *.ppt)

The Winner, the Thief and Science Week

Congratulations to Roy in 8A for he was the first to solve the finger print jigsaw last week - he must have sent it at lunchtime on the first day to beat the rest - do you know who's fingerprint it was? Roy, come to the Science office and collect your prize from Mr Taylor. The thief was named today as Dr Macgregor - once again thanks for all the emails accusing me and the furtive looks on the corridor because you thought it was me all week long. Dr M spent two days in jail over the weekend after analysis of video footage revealed this photo of her in lab 2. As punishment she has to do community service as a Chemistry teacher here at Bangkok Patana school for the rest of the year - she is appealing against the severity of the sentence. Don't forget to thank your Science teacher and especially the Science technicians (Khun A, Khun Gun, and Khun Pornpen) for all the exciting activities that were prepared for you last week. If you have any photos from Science Week that you would like to share then please email me.

Einstein's box snares photon

In 1927, Albert Einstein conceived of a box in which light was trapped and a single light particle, or photon, was released in a theoretical experiment to measure the relationship between mass and energy.

Eighty years on, French physicists say they have created Einstein's box: a device just 2.7 centimetres big that snares a photon, enabling it to be monitored from birth to death.

They publish their work today in the journal Nature.

Photons are arguably the ultimate existential particle in physics. By switching on a light bulb, you release a million billion of them every second.

But as soon as you see a photon, it dies, as its contact with the retina expends the energy that made it exist.

"Photons are easy to detect. You do it yourself, every second for instance when you are looking at a computer screen," says co-author Professor Jean-Michel Raimond of France's National Centre for Scientific Research (CNRS).

"But you do this only once. It's post-mortem analysis. We, though, can now analyse it in real time, while the photon is still alive."

The box is a cavity with walls made from ultra-reflective, superconducting mirrors able to trap a photon for about a seventh of a second.

That may not seem much but it is worth considering that, in the same time, a free photon would travel about a tenth of the distance from the Earth to the Moon.

A new way to count photons

The conventional way of counting photons is by a light detector that works by absorbing the energy by impacting particles. But the collision destroys the photons, so what is needed is a 'transparent' counter.

The French team says it has found the answer in a stream of rubidium atoms, which cross the box in which the photon is trapped.

Photons have an electrical field that slightly changes the energy levels of the atom, but in this case, not enough to let the atom absorb energy from the field.

When an atom crosses the photon's electrical field, this causes a tiny delay in the electrons that orbit the atom's nucleus.

The delay is measurable, using the technique of modern atomic clocks, which use electrons' orbit as a 'pendulum' to provide a precise time.

Quantum 'masterpiece'

In a commentary also published by Nature, Professor Ferdinand Schmidt-Kaler, a quantum physicist at Germany's University of Ulm, describes the achievement as an "experimental masterwork".

He says it has major implications for quantum computing, a field that proponents claim will make one of today's supercomputers look like an abacus.

Instead of using the binary digits 0 and 1 to hold information, quantum computing is based on a principle of quantum mechanics, changes of state, called superposition, that occur at the atomic level.

Quantum information, or a qubit, can be a 0 or 1 or simultaneously as both 0 and 1, amounting to a potential boost in data storage, but only useful so long as it can be controlled and accessed.

Photons, atoms and ions have been used as qubit carriers in this area of research.

The experiment demonstrates that "a stream of atomic qubits can be fully controlled by the qubit state of a trapped photon", says Schmidt-Kaler.

Related Stories

Einstein's tea-leaves inspire new gadget, News in Science 17 Jan 2007

Einstein at least 99.95% right, News in Science 15 Sep 2006

Einstein failed school, Great Moments in Science ABC Science Online 27 May 2004

Just another ordinary day in the Science faculty......

Science Week: Have you signed up for making explosive bubbles?

Science Week: Have you signed up? See the notice board 2nd floor near lab 5 (Physics) for exciting lunchtime activities

Science week: Finger print challenge

The year 7's will become CSI's trying to find out which science teacher stole the delicious ice cream as part of the Science Week. Can you solve this jigsaw fingerprint of one of the Scientists? Which member of the Science Department do you think it is? Click on the image to start solving the jigsaw. Post your guess as a comment below. First completed jigsaw as a screen print emailed to brta@patana.ac.th will win a prize!

National Science and Engineering Week 9-18th March

National Science and Engineering Week 9-18th March

Only two more days to go - have you signed up or any cool lunchtime experiments next week? See the notice board on the Physics side stairs 2nd floor for more details.

Vote for you favourite experiment here

National Science and Engineering Week 9-18th March

Here is the next experiment for you to watch...........

Vote for you favourite experiment here

Can you make these Water Spikes?

Here’s something to do for National Science and Engineering Week 2007! Now before we start I have a confession. I tried this out and it didn’t work. Distilled water yes, freezer at minus 11.5 degrees C hmmmm, maybe (didn’t measure it at the time). So I am throwing down the gauntlet to anyone who wants to give it a go. Send me a photo of your ice spike with your face and first name on a piece of paper next to it. Just so that I have proof y’understand – yes those Google Images are soooo useful at times aren’t they? All those entering will be put in a draw for a pack of AQA GCSE Sciences Flashcards courtesy of Hodder Murray (www.hoddereducation.co.uk) and a 100 baht snack card.

You will need:

Distilled water (you can get this from a petrol station)
Ice cube tray
Freezer

What to do:

Fill the ice cube tray with distilled water.
Place in a freezer whose air temperature is at least -11.5 degrees C.
Leave for an hour and a half.
You should see a short spike of ice protruding from each cube.

What’s going on?

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.
But you may find fuller explanations in the following websites:

You, too, can grow ice-cube spikes in your own freezer!

Ice Spikes

Got Spikes on Your Ice Cubes?

See video

Diagram of how spikes are formed

The draw will take place at 5pm on Wednesday 21st March.

Eclipse set to be 'best in years'

Skywatchers eagerly awaiting Saturday's total lunar eclipse say that the spectacle could be the "best in years". The eclipse begins at 2018 GMT, with the Moon totally immersed in the shadow of the Earth between 2244 and 2358 GMT. During "totality", only light that has been filtered through the Earth's atmosphere reaches the Moon's surface, making it appear a reddish colour.
The eclipse will be visible from the whole of Europe, Africa, South America, and eastern parts of the US and Canada. "They are beautiful events," said Robert Massey, spokesman for the UK's Royal Astronomical Society. "They have a really romantic feel to them as you look up because the Moon, which is normally pearly white, takes on this reddish colour." He added that it was totally safe to observe and no protective filters were needed because the Moon would actually be less bright than during a normal full moon.

See where the eclipse will be visible

Read more......