Science

The Science team like to introduce themselves, welcome you as a potential student next year and give you a bit of a flavour of what our current students are doing.

We’d also like to make a few suggestions for other interesting science activities that can be done at home.

Biology staff:

  • Neil Morley
  • Sadik Miah
  • Maarya Islam

Chemistry staff:

  • Amran Mohammed
  • John Hamlin
  • Salma Amanjy

Physics staff:

  • Steven Kearvell
  • Nigel Brownsmith

Task 1

Here’s some interesting finds we thought you may like to read:

Websites:

  • An award winning blog that brings together links of the latest developments in the biological sciences – interesting and well written (and with a sense of humour) it is a great way to keep up to date with what is going on: http://blogs.discovermagazine.com/notrocketscience/

Books to read

Periodic Tales: The Curious Lives of the Elements; Hugh Aldersey-Williams; ISBN: 9780670918119

Task 2

Biotechnology

Biotechnology is one of the new buzz words in Biology – all new and exciting, at the forefront of science and scientific advances. True, but it is also one of the older, more established branches of science. It includes: use of yeast in bread making and brewing; use of bacteria and fungi in the dairy industry; use of microbes in water treatment; genetic modification (human insulin, vegetable rennet, soya, Golden Rice); enzymes; cloning; plant tissue culture ..... Try the following:

Production of yoghurt:

Yoghurt is a fermented milk product, made using Lactobacillus bulgaricus and Streptococcus thermophilus .To make yoghurt all you need is a wide mouthed thermos flask, warm milk and some live yoghurt.

  • clean the thermos (vacuum flask) with hot water (be careful not to burn yourself)
  • fill with milk warmed to 45-50oC
  • add a couple of tablespoons of live yoghurt, seal and leave to incubate overnight
  • the milk will turn to yoghurt – live yoghurt has a bit of an acquired task, so add some fruit pulp or honey to make your own tasty (and cheap) alternative to shop-bought yoghurts http://homecooking.about.com/od/dairyrecipes/r/bldairy9.htm

Production of cheese:

It is possible to make cheese using bacteria (Lactobacilli) and if you tried the chemistry experiments suggested in the last newsletter, you would have seen it could be made from your breakfast ingredients (milk and orange juice). A traditional Indian cheese is made using milk and citric acid. Follow the instructions to make your own paneer.

  • bring 1 dm3 of milk to the boil in a pan
  • add 10 cm3 of fresh lemon juice, mix and continue to heat gently – the milk will curdle as the protein component (curds made of casein) separates from the liquid component (whey)
  • remove from the heat, let it cool and then filter through cheese cloth or muslin
  • rinse under cold water to remove excess lemon juice
  • let the whey drain out for about 20 minutes, place into a mould and press
  • use in your favourite recipe or see: http://www.bbc.co.uk/food/recipes/paneerwithspinach_86756 http://www.indianfoodforever.com/vegetables/paneer/

Task 3

Chemistry Sudoku

Task 4

A Physics Trick: Bernoulli Balls

A simple hair-dryer becomes a magical levitation device through an understanding of the principles of fluid flow.

Ingredients

  • hair dryer (make sure you have an appropriate power supply available!) **Caution: Remember hairdryers get hot! Keep the vents clear and don’t let it overheat**
  • small light balls (such as polystyrene balls available at most craft shops, or ping pong balls)

Instructions

  1. Orient the hair dryer so that the outlet is pointing directly upwards. Turn it on.
  2. Place a ball carefully in the flow from the hairdryer. It will balance in the air, appearing to levitate!
  3. Gently move the hairdryer from side to side – the ball will stay in the air stream, i.e. will also move back and forth. Repeat this process moving the hairdryer up and down.
  4. Carefully tilt the hairdryer – the ball will still stay in the airstream, hanging in mid-air with nothing directly underneath it.
  5. Try using balls of differing sizes, and challenge your audience to see how many they can place in the airstream at once.

How does it work?

The upward pressure from the hairdryer balances the downward force of gravity, keeping the ball 'levitating'. The more impressive part of this trick – being able to move the ball along with the hairdryer and angle it and so on – is based on the Bernoulli principle. This states that fast moving fluids (including gases such as air) are at a lower pressure than slow moving fluids. So the airstream from the hairdryer is at a much lower pressure than the air outside. A ball that is smaller than the diameter of the airstream can therefore be balanced within it – if the ball starts 'falling' out of the airstream to one side then the higher pressure of the air outside the airstream will push the ball back into the centre. This is the process that enables the ball to balance inside the airstream and move around as the hairdryer is moved around.

Tips for Success

Try to find a hairdryer with a 'cool' setting – it will last longer and allow you to perform the trick for much longer in one sitting, without the hairdryer overheating.Make sure that the balls aren't larger than the output of the hairdryer or it won't work. Tilting the hairdryer to too great an angle will cause the ball to fall out of the airstream.

Did You Know?

The Bernoulli Effect underlies the principle of the aerofoil. By encouraging air to flow more quickly over the top surface of a wing an upward pressure is produced by the slower moving air beneath. This phenomenon can also be demonstrated by holding up two sheets of paper and blowing between them. Instead of moving apart, they are drawn together. If you thought anyone could have worked this out, remember that Daniel Bernoulli was awarded his masters degree at the ripe old age of 16.

For this and more physics tricks from the IOP (Institute of Physics) visit: http://www.iop.org/resources/videos/physics-tricks/index.html

 

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