Monthly Archive for February, 2009

Could you be a CSI and identify blood spatters

Blood spatter from New Scientist
This just in from New scientist
Bloodstain analysts claim to be able to identify how a bloodstain was created – whether by dragging, dripping, or impact at close range – simply by looking at it. But no-one has tested the accuracy with which they can do this until now.

Brian Gestring of Cedar Crest College in Allentown, Pennsylvania, conducted a preliminary study in which 92 professional analysts and 65 non-experts were asked to name the mechanism by which ten different blood patterns were created. The blood patterns were not from real crime scenes, but were recreated using animal blood.

He found that the experts got it right 97% of the time, while laypeople guessed correctly in 21% of cases. The study, which was presented at a meeting of the American Academy of Forensic Sciences in Denver, Colorado, last week, is a first step towards being able to quantify an error rate for bloodstain analysis. Jurors could be presented with the error rates when hearing evidence in court.

The next step will be to recreate an entire crime scene and test the ability of analysts to interpret what has happened.

See the New Scientist quiz here I got 80% – how did you do?

Links
New Scientist

Australian Solar Feed In Tariff Petition Tops 10,000

lights
Melbourne, Victoria, 25 February 2009. A petition calling for the Federal Government to implement a national solar gross feed-in tariff program has already gathered over 10,000 signatures in support, less than a month after it was launched.

The FeedInTariff.com.au petition is backed by key lobby and industry groups, including the Australian Greens, the Alternative Technology Association, a range of environmental sites and renewable energy bodies.

FeedInTariff.com.au calls for the introduction of a uniform gross feed-in tariff system similar to the model being launched by the ACT Government, where owners of renewable power systems are paid a premium rate for each kilowatt hour of electricity they produce.

Each state in Australia currently has its own tariff system. Most programs, where they exist, use an inferior net model, where only surplus electricity generated receives a premium payment.

Energy Matters spokesman Andrew Scarlett said the organisation had been lobbying for a gross feed-in tariff for a long time. “We were frustrated by the lack of action from more subtle behind-the-scenes efforts, so we decided to take this more public initiative.”

“Feed-in tariffs work. They’re good for the economy, good for the environment and they make people part of the solution to climate change. This petition tells Government its electors are watching, they want to be part of the solution and expect Government to give them that opportunity”, Mr Scarlett said.

Energy Matters also launched a Facebook group “Help PM Rudd Choose a solar future“, which accumulated more than 2,000 members.

“The incredible response to the initiative has not been driven by paid advertising, but mostly through word of mouth by Australians concerned about the country’s future. These people are saying they want to be part of the solution to the problems caused by coal. The results show considerable support for a national gross feed-in tariff. The electorate wants Prime Minister Rudd to shift the focus from coal to a solar future for our nation”, Mr. Scarlett said.

“All that remains for a solid feed-in tariff program to come to fruition is for political will to reflect the will of the voting public. Successful gross feed in-tariff programs have been established around the world, resulting in marked increased uptake of solar and wind power, stimulating local economies and helping governments towards their renewable energy targets.”

How do you combine multi dimensional mathematics, the great barrier reef and hand crafts

http://sydneyreef.blogspot.com/ image from Institute For Figuring
The answer is the Sydney crochet coral reef. An offspring of the crochet coral reef presented by Margaret and Christine Wertheim and initiated by The Institute For Figuring, originally inspired by geometric models of hyperbolic space developed by mathematician Dr Daina Taimina in 1997.

Hyperbolic space is intriguing on its own with a complex relationship to the work of Einstein to mention just one. As an idea though it is another in that long running set of understanding changes that lead to new understanding of the world. It is something that everyone should try and think about at least once.

That is where the Coral reef and crochet come into it. Dr Taimina discovered that one of the simplest ways to represent the growth of hyperbolic space was to crochet it. If you crochet the right pattern you form shapes reminiscent of hyperbolic space. What’s more when you look at your crocheted things you discover they are also reminiscent of coral. Another little known fact is that coral and a number of other marine organisms grow in hyperbolic ways.

Put it all together as the Wertheim sisters did and you have a hyperbolic crocheted coral reef. Three Sydney artists have been inspired to build/grow their own. In stitches, the Sydney reef artists, are calling on the community to join their collective of coral reef crocheters (is that the word). Get a group of like minded people and crochet away.

While you crochet think about hyperbolic spaces, discuss the demise of Euclid’s fifth axiom, you could also discuss the parallels between that and the decline in coral reefs around the world, or why it is that you know so few mathematicians and yet maths is all around you.

Watts in a name – Wattzon, another footprint calculator

I plugged my self into an new online footprint calculator -yes another one, to check myself out. As always there are good and bad points to note. The site is Wattzon

Positives
1. It uses Watts to measure your footprint – which is a logical way to analyse what is predominantly an energy topic. Watts are of course the units associated with household electricity.
2. You can compare yourself to other people and the world
3. Wattzon calculates your portion of published government activity
4. This footprint takes account of the lifecycle energy of the stuff you own

Negatives
1. A Watt is a difficult unit for many people to get their heads around – but then aren’t they all. Maybe laps of the oval would be better (its always easy to make suggestions from the sidelines)
2. Comparisons can lack validity (see 3 & 4 below). My energy use might be like apples to someone else – especially Americans which is the only comparison I get.
3. Unfortunately the energy in stuff can be questionable as well – for instance my scooter is supposed to embody more energy than a motorcycle because Wattzon gives scooters a 15 year life cycle and motorcycles 40 years – my scooter is already 40 years old.
4. My consumption is greater because I have gone through the time consuming process of adding extra stuff not on the standard list.
5. If I compare myself to a wind turbine I get a huge picture likewise for solar voltaics – wow such a big impact, compared to 5 gallons of oil a day- so little consumption. You can’t compare my annual wind/solar use to my daily oil use.

Overall
Wattzon offers a new approach and a new unit of comparison, but like all generic footprint tools my specific life translates badly. There is no allowance for how I get my energy or my food.

I like the idea of footprinting tools but they all are hindered by the need to make the process quick for the internet generations/ rapid twitching, so sacrificing parts of the impact.

Anyway here is my footprint according to Wattzon.



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