Science Infoblog

Marie Menzies and her year 9 social studies class took over the science laboratory to prepare a series of organic crop sprays. They are non toxic and decompose naturally. They don’t leave hidden toxic residues that can build up over time. Their use is sustainable

In social studies the long term impact of  our activities on ourselves and the planet (our mobile home) is important.

Pest control on crops is important. We farm intensively to grow enough food for the population to survive. Nasty chemicals are required to control organisms that damage our food plants

The government keeps a register of these chemicals with ERMA, the Environmental Risk Protection agency.

If you attack my potato plants when they are growing I will retalliate with weapons of mass destruction.

Chemistry finds its way into every aspect of our life including my vege garden. Food science is chemistry that tastes good.

My first crop of potatos  two years ago wilted in the summer dust and a belated attempt to recover the situation failed in the mid winter frosts. A single bag of potatoes was a poor reward for a lot of effort.

With one set of potatoes ready to flower in mid November last year the unthinkable happened. Leaves at the top of the plant began to curl up and droop.

On closer inspection the cause was soon apparent. The unhealthy plants were crawling with “stink bugs” or Nezara viridula (linnaaeus). Apparently these little suckers pierce plant tissue, remove the goodies and totally deflate the new growth at the top of the plant. The damaged leaves like pieces of punctured balloon are all too visible in the photos.

McGregor’s general purpose insect spray had an immediate impact on the pests. The active ingredient in the insecticide is diazinon.

Formulations containing diazinon have been registered for use in New Zealand since 1967. There are currently 32 products containing diazinon that are registered for agricultural and veterinary medicine use including 14 insecticides and 18 veterinary medicines according to ERMA (Environmental Risk Management Authority NZ).

and now the chemistry….. Compounds like diazinon need to be treated with a lot of respect. Diazinon is closely related to chemical warfare nerve agents such as Sarin and Tabun

Tabun and sarin were among the agents used by the Iraqi government when it killed 5,000 Iraqi Kurds in Halabja in 1988. Liquid sarin in perforated bags killed 12 people in the 1995 attack on the Tokyo underground.

Chemists have discovered ways to synthesise new molecules with designer properties. Nerve gasses wreak havoc on the transmission of nerve impulses in the nervous system.

The components of molecules responsible for their chemistry are known as functional groups. Chemists have a large tool kit of functional groups that can be unscrewed from a molecule and replaced by another with different properties. Diazinon is a good example. The same purple phosphorus atom and three red oxygens lie at the deadly hearts of these nerve agents.

Should we be using weapons of mass destruction in our gardens?

To sustain life on this planet you will need all the skills you learn in social studies together with the ability to understand complex science. We need a generation of young citizens who are able to engage in intelligent debate and hold those in authority accountable . Good luck your kids depend on you.

APPENDIX

ERMA  NZ maintains according to its own information a short list (actually its quite long) for which there is evidence that the risks faced by those who use these substances or come in contact with them after someone else has used them (you) may not be adequately managed

Here is the list, look out for them on labels

According to Wikipedia Civil Engineering is a discipline that deals with the design construction and maintainance of structures like bridges, roads,  canals dams and buildings.

The World Trade Centre consisted of 7 buildings on a 16 acre Plaza in lower Manhattan. 19 terrorists hijacked four aircraft on the morning of September 11 2001. The hijackers crashed two planes the Trade Centre towers which collapsed within 2 hours. A third aircraft crashed into the Pentagon building in Arlington,Virginia and the last one nose dived into a field near Shanksville in Pensylvania.

Just why the “twin towers” collapsed has been the subject of various conspiracy theories:

• controlled demolition rather than structural weakening due to fire
• the Pentagon was hit by a missile
• the hijacked planes were replaced by planes carrying explosives

Eight years on and even after thorough scientific investigation the myths continue to grow in sophistication. Apparently nano-thermite particles (ask any 6th form chemist about factors controlling reaction rates and what highly exothermic means) have been found in the rubble of Ground Zero by a Danish professor. Nano-thermite is a highly reactive compound used by the US Department of Defence. It is also used to lainch rockets.

Civil engineers are skilled in the use of science and mathematics to build structures that don’t fall over. The Auckland Harbour Bridge needed extra capacity hence the addition of nippon clipons in 1965. The two-lane box girder sections added on each side of the bridge doubled the traffic lanes to eight. Structures must be  maintained and cracks discovered in 1987 and cracks/material fatigue found  in 2006 could not be ignored. Generally engineers get it right and we trust their safety margins. Currently vehicles are restricted to weights of 13 tonnes or less after further concerns that a traffic jam stopping flow on the bridge could cause the clip-ons to unclip.

Similarly we don’t expect the sky tower to blow over in high winds although the revolving restaurant at the top is sometimes closed in storms as the swaying motion causes soup to slurp over diners’ bowls. Swaying is good as far as engineers are concerned. The alternative, snapping to release strain is not a popular choice!

Civil engineers can use science and mathematics skills to determine the likely causes when buildings and other structures do fail catostrophically.

Purdue University worked with the American Society of Civil Engineers to produce an analysysis of the most likely chain of events leading to the collapse of the twin towers eight years ago. This involved thorough mathematical and computer modelling of the forces involved using the original building blueprints. Data defining the properties of the construction materials were also fed into the calculations.

Structural weakening due to fire is the only credible scientific theory explaining the collapse of the twin towers.

Civil Engineering at the Univerity of Auckland:

Civil Engineering is a four year course requiring good seventh form grades.

from the student handbook:

• to gain admission to University of Auckland you must gain the university Entrance Standard and be selected into a programme.
• You will be allocated a ranked score based on your best credits at level 3 or higher.
• A maximum of 5 approved subjects weighted by the level of achievement attained in each set of credits.
• If you achieve fewer than 80 credits at level 3 the ranking will be based on those credits you have achieved over a maximum of 5 approved subjects at level 3 weighted by the level of achievement.
• The approved subjects are determined by NZQA and are available at www.nzqa.govt.nz/ncea
• You are are strongly advised to take achievemnt standards as preparation for University study.
• The guaranteed admission score for BE(Hons) in 2009 is 240 with a minimum of 18 credits at Level 3 in Maths with calculus and Physics.
• The rank score is calculated by awarding 4 point for Excellence, 3 for Merit and 2 for Achieved for up up to 24 credits in each approved subect at level 3 over the last two years.
• The maximum possible score is 320

NOTE……NOTE…….. The importance of mathematics in the study of science at University

Are you interested in any of the following careers:

• Stock Agent
• Agriculture Mechanic
• Sheep/Beef Farmer
• Fertiliser Consultant
• Shearer

 Do you have the ability and interest to follow a particular career in the agricultural industry?
This programme offers to link senior secondary students to young Industry Mentors already working in a career that you might wish to check out. This may lead to work experience opportunities e.g. Gateway.
The help you will receive will differ from normal careers programmes. You must be willing to actively participate in communication with your Industry Mentor via their preferred medium e.g. text, phone, email, Face Book, Bebo.

Check out information with the Careers Department in the first instance but look at the links below.

In2 the Field Guidelines.

Student Application Form.

A bunch of very talented young scientists from Glen Eden Intermediate came along to the labs to do some investigations into the properties of liquids. They brought with them samples of work from a previous visit which were outstanding.

Not content to talk about the science of liquids there were also discussions around the Hadron Collider and the search for the mysterious Higgs Boson. Graham, a dad who always comes along to these sessions  talked about Nikola Tesla a Hungarian inventor, mechanical and electrical engineer.  A former student of Green Bay built a working Tesla coil as a project, This equipment generates the huge lightening bolts that bring Frankenstein to life in horror movies. Tesla coils are notoriously difficult to construct as the physics is so complex.

Anyway students investigated:

• the particle nature of liquids
• what happens when liquids boil
• liquids that don’t mix
• emulsions
• and finally made a cold cream

Here is the worksheet if you want to do any more work

Physics can be truly weird and often counter intuitive. Everyone will be familiar with the reference to Star Trek in the title of this post and be aware that  Klingons are very nasty extra terrestrials.

It turns out that Physics is stranger than fiction and Newtonian mechanics which describe the world around us (speed =distance/time for example) become hopelessly inadequate as you approach the speed of light. Einsteins Theory of General Relativity predicts time dilation or stretching. If you take a summer holiday on a beach  near a black hole, time is dilated and the vacation lasts longer. As a consequence you return younger than friends who stayed at home using botox to slow  ageing. G P satellites  take time dilation into account when they compute accurate positions. Strange but true.

Ye canna change the laws of physics, laws of physics Jim

The laws of physics at Rainbows end…….. feel the force

…….and finally the worksheet for anyone who has lost the original. Eric and Bonita would appreciate feedback on the field trip. Any questions?