Mon 21 Dec 2009
Posted by andrew under Musings Comments
Disclaimer: If you already knew this stuff, I apologise, but I found it pretty cool.
Our eyes have three different types of cone cells that allow us to see a huge range of colours. Okay, so you knew that already, but I haven’t gotten to the good bit.
Televisions, computers, magazines and other visual media all exploit the fact we have those three types of cells to create the range of colours we see in them. They use three different pigments or three different lights, in various combinations, to do this. Hence the three “primary colours“. No, that wasn’t the good bit either.
Different animals have different numbers of cone cells in their eyes. Sea mammals (like dolphins) have just one type of cone cell, so can’t really tell colour at all. Most other mammals, except primates, have two types of cone cell. Most birds, and some fish, have four types of cone cells. Pigeons and butterflies are believed to have five types of cone cells. Stomatopods are thought to have as many as twelve different colour receptors!
Actually, some people (particularly women) are believed to have four types of cone cells. If ordinary people can see 1 million colours, they can see 100 million different colours.
But for these women, and most birds, butterflies and stomatopods, the three primary colours don’t always represent reality as they see it with their naked vision. You might show them a picture of a colourful flower on a computer monitor, but it is generated by red, green and blue dots, and so won’t look like the actual flower.
I wonder if the different species cone cells have evolved to help us find food and avoid predators, and if so whether you could match up the different spectral sensitivities of species’ cone cells with the colours of different plants and animals to determine if they evolved together.
Oh, the cool thing was the women with super vision. But, I think the rest of it is pretty cool also.
Tags: biology, color, colour, cone cell, cones, spectral sensitivity
Mon 14 Dec 2009
Posted by andrew under MusingsNo Comments
I use and believe in the value of anti-virus software to protect my PC against malware. However, it appears that the full level of protection will soon come to an end, if it hasn’t already.
My home computer of choice is a laptop. It’s not by any means a highly performant, always-on, always-connected server. When I need to use it, I power it up, do what I need to do, then power it down. Mostly I use the web browser – it doesn’t need a whole heap of grunt.
More people are turning to these as their preferred computers. Laptops now outsell desktops. Netbooks are expected to sell like hotcakes.
Unfortunately, the following facts don’t seem to paint a pretty picture for me:
- During the week, I use the computer for at most a couple of hours per day.
- The virus scanner takes a couple of hours to run.
- By default, the scanner does a complete computer scan every day (a practice recommended elsewhere).
- Over time, I will have more disk to scan (e.g. you can buy about twice the size hard disk for the same money each year).
- Over time, I will have more files to scan (e.g. browser caches will contain more since more objects appear on each web page every year and HTML5 techniques involve storing data locally).
It has gotten to the point where I turn off the computer prior to the virus scan finishing. The virus scan effectively never completes, so at no point can it assure me that the computer is free of malware.
I can see some solutions to this. None of them are ideal.
Firstly, I will have to give up on daily scans. If it never gets to finish anyway, then why should I pay the price for the massive slow-down that I get from constant scanning?
I could also set the browser to delete all files in the cache when I exit (or at least delete them on a regular basis). However, I suspect most browsers lack this feature today.
Finally, I could use a Mac or a Linux PC instead. Since there is less malware for those platforms, scanning should be much faster.
Tags: antivirus, laptop, malware, netbook, PC, protection, security, virus
Mon 7 Dec 2009
Posted by andrew under Musings Comments
Dear Tony Abbott,
Your new climate change policy for the Liberal Party is certainly interesting: a 5% reduction in national emission levels from those of the year 2000 by the year 2020, but without implementing an energy trading scheme or carbon tax. Although it doesn’t sound like you’ve quite settled how you’ll achieve this yet, you are looking at options such more regulations and new government subsidies. You are clearly open to options which the Labor Party is traditionally closed to.
However, as someone who might be willing to take on radical yet reasonable policy positions, I would like you to consider a simple measure that will cost the government nothing, yet easily achieve your target. Pass a law that makes it illegal to eat meat.
The United Nations’ Food and Agriculture Organisation 2006 report “Livestock’s Long Shadow” found that 18% of global greenhouse gas emissions come from the livestock sector, which is more than the emissions from all the cars in the world. We have been looking for emission savings in all the wrong places.
Having Australia become the first country to go vegetarian would demonstrate global leadership and really show those United Nations guys that we can do without their pesky energy trading scheme. If China can introduce a one child policy, then surely we can introduce a one food policy. Almost a third of Indian people are vegetarian, which is like if seventeen entire Australias were vegetarian. The global thinking is consistent: I have been assured by a very knowing fellow in London (author of the Stern Review on the Economics of Climate Change) that people ought to go vegetarian for the climate’s sake.
According to the Australian Government’s Department of Climate Change, “Tracking to Kyoto and 2020″ report, our emission levels in the year 2000 were 553 million tonnes of CO2-equivalent gasses. A 5% reduction is a reduction of 27.7 million tonnes. Vegetarianism will easily achieve this.
As the Garnaut Climate Change Review notes, “Australia’s per capita emissions arising from agriculture are more than six times the world average, more than four times the OECD average” and the Agriculture, Forestry & Fishing industry is the largest industrial contributor to emissions, accounting for 29.3% of industrial emissions. Garnaut attributes 123.7 million tonnes of emissions to beef cattle alone.
Meat & Livestock Australia estimates that “50.7kg of red meat was available for consumption by each person in Australia in 2006-07″ while a Japanese study estimates that each kilo of beef “generates the equivalent of 36.4 kilograms of carbon dioxide”. At a population of 20 million, that is an equivalent of about 37 million tonnes of greenhouse gas from meat eating.
Even more dramatically, an analysis by the Vegetarian Network Victoria forecasts Australia becoming completely carbon neutral within 3-5 decades of adopting vegetarianism if land currently used by cattle was reforested. Ask the Labor Party if their tax is able to achieve that.
There is also the opportunity to snooker your colleague Mr Turnbull, who seems to be positioning himself as a sort of Australian Al Gore. By adopting vegetarianism, you can occupy the highest of moral ground, while also being against taxation and climate change. High ground is the safest position to be in these troubled times.
Your role-model and mentor John Howard took strong measures in 1996 to ban all the dangerous guns (thank goodness we got to keep the safe guns). This type of bold leadership is what we need in the climate crisis of 2009.
Tags: a modest proposal, Australia, climate change, greenhouse gasses, jonathan swift, philosophy, vegetarianism