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Welcome back!

Posted: September 27, 2012 by Mr Pimentao in Biology, Chemistry, Physics, Uncategorized
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Loreto Science is back , and welcomes everybody to a new year of discovery.
A year of exciting activities is just beginning, so we’d like to invite you to join Miss Gilleece on a journey through the world of Mad science every Thursday at 12:45 in SC5.

This week saw year 7 and 8 students getting to grips with lighting effects. The group enjoyed using prisms and filters to come up with some spectacular images (and stories!) for their light shows – with some trying to act out an X-Factor audition!

The club will hopefully see students gaining a Crest award by the end of the year; some of the topics we will touch on will include rockets and medical physics, alongside a project the girls will design for their Crest award.

So if you haven’t already come, don’t worry!! You can drop in any Thursday, but I’d love to see you there every week! 🙂

See you all next Thursday!

Miss Gilleece

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Is there anybody out there?

Posted: February 26, 2012 by Mr Pimentao in Biology, Space
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Forget about little green men, ET or Alien – they don’t exist. Or at least we don’t have any proof that they do. Despite this, the search for extra terrestrial life is now as lively as ever : from the discoveries of planets orbiting other stars in our galaxy to the SETI (Search for Extra Terrestrial Intelligence) project, scientists are scrambling to find a glimpse of life away from our own home planet.

Exoplanets and the Goldilocks principle

Exoplanets are planets that orbit stars other than the Sun. For decades astronomers had suspected that other stars in our galaxy might have planets orbiting them ( just like the Sun has Mercury , Venus, Earth, and so on… ) Like all the other scientific predictions, you can only confirm it if you have enough evidence to back it up. Guess what – for the last ten years or so, astronomers have found evidence that in fact there are planets orbiting stars in our galaxy.

Planet in transit across the star disc: Picture: ESO/L. Calçada

The problem with seeing planets orbiting stars so far away from us is that the brightness of the star outshines the tiny amount of light reflected by the planet. Only very recently , with developments in image processing software and improvements in CCD technology have scientists been able to detect planets. But this doesn’t even mean that we can actually “see” the planets – we can’t , at least not directly. We must look for clues in how the light from these stars reaches us.

One way of telling if a star has planets orbiting it is called the “Planetary transit” method.   Whenever a planet is placed between us and the star, we can detect a small decrease in the brightness of the star. Imagine a mosquito flying in front of a lamp – whenever it flies between us and the lamp, we can see that the lamp seems to get dimmer because the mosquito blocks a tiny bit of its light.  The same happens with a planet that orbits around a far away star. Every so often the planet blocks some of the star’s light and the star appears to have dimmed by a  little amount. Scientists look out for these tiny changes in the brightness of stars and use their data to compare the size of the planet with the size of the star.

This is all fine, there are more planets in the Universe than those we have learnt about in Miss Gileece’s lesson…. My Very Easy Method Just Speeds Up Naming Planets… But is there life living on them? Do they have BBM?

The answer is….. we can’t tell if there is life on any of the exoplanets that were found, let alone whether or not they have BBM. One thing we know is that life as we know it has first appeared in liquid water –  right here on Earth, millions of years ago. So, we can be certain that planets where liquid water exists are more likely to have life.  The planets that obey this condition must be at the right distance from their star for the temperature to be just right for liquid water to exist. Depending on the kind of star , and on the size and composition of the planet, the temperature is just right for liquid water if the planet orbits the star at a range of distances often called “the Goldilocks region”.

This raises the question: how do we know if these exoplanets have liquid water? And if they do have liquid water does that definitely mean that they have some kind of life?  Life on Earth evolved in water , but there are so many variables to take into account that it is currently impossible to prove that there is indeed other life forms in the Universe.

So, if you were expecting a YES or NO answer to the question you may now be disappointed (or not!). All we can say is that most probably there is life somewhere in the Universe, possibly in a planet orbiting one of the hundreds of million stars in our own galaxy, the Milky Way.

Dancing Fire!

Posted: January 7, 2012 by Mr Pimentao in Physics, Uncategorized
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Sound seems to have caught the eye here at Loreto’s science cyberspace presence.

Whilst “youtubing” aimlessly like a headless chicken, I came across several videos showing a Ruben tube.

This is a perforated tube connected to a supply of flammable gas on one end, and attached to a speaker on the other end. As the gas flows through the tube holes, the (standing) sound wave created inside the tube by the speaker causes areas of high and low gas pressure. If you fire the gas up, it becomes an impressive flame show. The height of the flame is taller in the areas of higher pressure, so it acts as a visual display of the sound wave that travels inside the tube.

Some people like to play a single note on the speaker and are happy with that. Others experiment with all kinds of sound : from dubstep to glam rock!

Videos:

Mythbusters playing with Rubens tube

Another one bites the dust on Rubens tube

Bad romance on Rubens tube

The most endangered cat – from Iberia

Posted: January 5, 2012 by Mr Pimentao in Animals, Biology
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Just over 100 animals make up the remaining population of the Iberian Lynx

The loss of their habitat to farming and tourism development in southern Portugal and Spain, added to shortages in rabbit availability due to myxomatosis have brought this species close to extinction.

For 30 years, conservation efforts have managed to save the species from extinction, but it has been very hard to maintain stable breeding populations. Today it is estimated that there are only 38 breeding females in the wild.

Links:

Saving the Endangered Iberian Lynx in Europe – video from National geographic

Iberian lynx (Lynx pardinus) video

WWF

The Sun Project

Posted: January 4, 2012 by Mr Pimentao in Engineering, Physics, Space
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We sometimes take things for granted. Things like the food on our plate, the air we breathe, the water running from our taps. All of these would not be there if it wasn’t for our star, the Sun.
The Sun Project is an Astronomy and Engineering club.

The pupils involved have been developing solar panels to heat up water, investigating solar cells and how they can be used to build toys, or observing the surface of the Sun. Everyone is welcome to join at any time.

 

Solar storm, October 2003

Non Newtonian fluids

Posted: January 4, 2012 by Mr Pimentao in Physics
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Many people have heard of Sir Isaac Newton. He is famous for developing many scientific theories in mathematics and physics. Newton described how ‘normal’ liquids or fluids behave, and he observed that they have a constant viscosity (flow). This means that their flow behaviour or viscosity only changes with changes in temperature or pressure. For example, water freezes and turns into a solid at 0˚C and turns into a gas at 100˚C. Within this temperature range, water behaves like a ‘normal’ liquid with constant viscosity.

Typically, liquids take on the shape of the container they are poured into. We call these ‘normal liquids’ Newtonian fluids. But some fluids don’t follow this rule. We call these ‘strange liquids’ non-Newtonian fluids.

The viscosity ( how “runny” a fluid is) of a non-Newtonian fluid depends on things such as the stress, or pressure applied to them. This means that a quick change in the pressure applied to such a fluid might change its viscosity.

Cornflour solution on a speaker cone.

This is the reason that explains the formation of these cornflour “creatures” . Corn starch is a shear thickening non-Newtonian fluid meaning that it becomes more viscous when it is disturbed. The changes in pressure created by the sound vibrations change the viscosity of the fluid, and the result is fantastic. Check it out here.

Another classic example is Mr. Tickle walking on custard.