Author Archives: alistair

A chunk of ice the size of a small country has broken off the Antarctic

There is quite a lot of news at the moment about a large piece (a little smaller than Swaziland) of ice shelf that recently broke off Antarctica. You can read about it here: National Geographic, Wired, BBC.

Ice shelves are made of ice already floating on the ocean so this incident won’t raise sea levels, but these shelves are holding back glaciers which will raise see levels. As the floating ice shelves break away there is nothing to hold back the land based glaciers which run faster and do raise sea levels.

These ice shelves are notoriously sensitive to warming (another one broke off during a brief warming period around 1920) so they do act as good early indicators of global warming happening – apparently “average Antarctic temperatures have risen 3 degrees (Celsius) over the past 50 years!”

If you are interested there is an busy debate going on in the comments section of the Wired article. Even if you aren’t that interested, I think you should be worried.
Ice melting in the Antarctic

Moths remember what they learned as caterpillars

Moths can remember lessons learned as caterpillarsNational Geographic recently had this article about experiments showing that moths can remember some lessons that they learned while they were caterpillars. The whole of metamorphosis is amazing, weird and interesting, but this is a question that didn’t even occur to me.

Anyway, it turns out that a caterpillar brain gets completely reorganized during metamorphosis, but a small part does remain intact – “the brain is not completely taken apart and rebuilt from scratch”

The experiment involved teaching caterpillars to avoid a certain smell and then checking if they remembered the lesson as adults – which they did.

Not sure why I find this interesting, but it’s the kind of random fact that appeals to me…

Do Stuff in Cape Town – my new project

If things have been a little slow on this blog lately it’s because I have been working on something new. It’s a site called Do Stuff in Cape Town and I have described it as an encyclopedia of activities in and around Cape Town.

The cool thing about it is that it works like a Wiki so anyone can contribute to it. I have developed it so that anyone visiting the site can easily:

  • Create new activities – there is a simple form for adding new activities
  • Update existing activities – say there is some detail or tip that you would like to add to an existing activity
  • Rate activities – it’s as simple as clicking on the star rating you want
  • Browse/search activities – I have put quite a lot of thought into making this as simple as possible
  • Subscribe to new activities – Get updates when new activities are added to the site

I have tried to make everything as simple as possible, but please give it a try and let me know what you think. Add an activity, or browse through those that are already there. I think that the site is almost ready, but I would really appreciate feedback!

Some of the activities that have already been loaded:

Interesting info about climbing Everest

Ronnie Muhl on Mount EverestLast night I went to a talk by Ronnie Muhl about climbing Everest. He is a South African guy who had to turn back 200m from the top in 2006, but went back last year and made it to the summit. It was an interesting talk overall, and actually helped me to get over my drive to climb Everest.

Anyway, some of the interesting things from the talk:

  • The Chinese have a massive presence at base camp where they are preparing for the Olympic torch. They are planning on taking the torch to the summit of Everest on the way to Beijing and have been preparing since last year. While Ronnie was there they were experimenting with torches that could stay alight in the cold, wind and low oxygen of Everest!
  • It is said that acclimatisation is so important that if you dropped someone off at the top of Everest they would be unconscious in 3 minutes! Ronnie and his team spent 4 months on the mountain getting acclimatised. Imagine 4 months living in a tent in freezing conditions like that…

Ronnie Muhl on Mount Everest

  • Ronnie talked about how climbers keep things in their sleeping bags to prevent freezing. Water bottles and electronics (to prevent batteries from draining) are kept in there and make rolling over tricky. He also explained that there is just no way that you will get up for a pee, so you keep a bottle handy for those purposes. The cheeky thing is that you have to keep the pee bottle in your sleeping bag too otherwise it will also freeze!
  • On his last expedition Ronnie walked past the corpses of 7 other climbers
  • In his 2006 expedition 2 of the climbers in Ronnie’s team died on the mountain
  • Ronnie himself had several close calls during his climbs – mostly related to falling and not being able to get back going. One story he told was about tripping on some old rope and landing up hanging upside down over a steep 3km fall! Ronnie hikes with a personal sherpa and in this case, as well as several others, it seems that his sherpa was the difference between life and death
  • There is quite a lot of junk on the mountain – discarded by decades of desperate climbers. You have to be really careful not to hook onto some old decaying rope while climbing (apparently they color code the newer ropes – so you just have to remember to hook onto the blue rope!). In an effort to clean things up, the sherpas get $20 for each empty oxygen canister they bring down. Apparently one of Ronnie’s sherpas was able to go back up the mountain and brought down 5 empty canisters!
  • There is a restaurant near the base of the mountain where those who have summited can eat for free for the rest of their lives
  • Due to the crazy stuff the Chinese government is doing in Tibet at the moment all expeditions have been canceled!
  • Accurate weather reports are really important for a successful climb – but they are expensive. Ronnie and his team paid R40,000 for weather reports in 2007!

Price really does impact enjoyment

The Economist recently ran an interesting article on the impact of price on our perceptions of quality. It seems obvious that price would have an impact on the expectations of quality.

However, a recent paper has used brain scans to show that people really do enjoy wine more when they think it is expensive.

Experiment

  • Volunteers were asked to rate 5 wines of differing prices (from $5 to $90 a bottle)
  • What the volunteers didn’t know is that there were actually only 3 different wines – 2 of which were served twice at different prices
  • While tasting the part of the brain responsible for registering pleasant experiences was scanned

Results

  • The wines tasted twice at different prices were rated as better when served at a higher price
  • The brain scans showed that people really did enjoy a wine more when they thought it was more expensive

A follow up blindfolded experiment was done where volunteers weren’t given the prices. In that case they rated a wine tasted twice as the same both times. This shows that it is the price that substantially impacts enjoyment.

So the ideal is to have a situation where you are paying for a medium quality product but you believe it is worth a lot more. The key is making sure that you actually believe it is worth more.

We have been using incorrect URLs all this time

I learned a couple of days ago that I was typing in web addresses (URLs) incorrectly. It turns out that there should be a slash (/) at the end of the URL that you enter. When you omit this slash your browser and the server work out the problem – but it takes some time.

This is explained in detail in this article. Here is an example of what is happening:

  1. You ask the server for: http://alistairpott.com
  2. The server says that page doesn’t exist – you mean (note the slash): http://alistairpott.com/
  3. Your browsers says OK and then asks for http://alistairpott.com/
  4. The server sends back the page

It’s not quite this simple (this only applies when you are not referencing a file directly), but the principle is there. You can often see this is happening – go to a site and you will see that once the page is loaded there is a trailing slash in the URL.

Entering the correct address (with a slash) prevents the first 2 steps and can speed things up. How much of a speed up? Probably not much.

Tax breaks explained using a beer analogy

I was emailed this analogy illustrating progressive tax a while back. It’s brilliant – we need more clear explanations like this. A similar one for evolution would be great…

Suppose that every day, ten men go out for beer and the bill for all ten comes to $100. If they paid their bill the way we pay our taxes, it would go something like this:

  • The first four men (the poorest) would pay nothing
  • The fifth would pay $1
  • The sixth would pay $3
  • The seventh would pay $7
  • The eighth would pay $12
  • The ninth would pay $18
  • The tenth man (the richest) would pay $59

So, that’s what they decided to do.

The ten men drank in the bar every day and seemed quite happy with the arrangement, until one day, the owner threw them a curve. “Since you are all such good customers,” he said, “I’m going to reduce the cost of your daily beer by $20.” Drinks for the ten now cost just $80.

The group still wanted to pay their bill the way we pay our taxes so the first four men were unaffected. They would still drink for free. But what about the other six men – the paying customers? How could they divide the $20 windfall so that everyone would get his ‘fair share?’ They realized that $20 divided by six is $3.33. But if they subtracted that from everybody’s share, then the fifth man and the sixth man would each end up being paid to drink his beer. So, the bar owner suggested that it would be fair to reduce each man’s bill by roughly the same amount, and he proceeded to work out the amounts each should pay. And so:

  • The fifth man, like the first four, now paid nothing (100% savings)
  • The sixth now paid $2 instead of $3 (33%savings)
  • The seventh now pay $5 instead of $7 (28%savings)
  • The eighth now paid $9 instead of $12 (25% savings)
  • The ninth now paid $14 instead of $18 (22% savings)
  • The tenth now paid $49 instead of $59 (16% savings)

Each of the six was better off than before. And the first four continued to drink for free. But once outside the restaurant, the men began to compare their savings.

“I only got a dollar out of the $20,” declared the sixth man. He pointed to the tenth man,” but he got $10!”

“Yeah, that’s right,” exclaimed the fifth man. “I only saved a dollar, too. It’s unfair that he got ten times more than I!”

“That’s true!” shouted the seventh man. “Why should he get $10 back when I got only two? The wealthy get all the breaks!”

“Wait a minute,” yelled the first four men in unison. “We didn’t get anything at all. The system exploits the poor!”

The nine men surrounded the tenth and beat him up.

The next night the tenth man didn’t show up for drinks, so the nine sat down and had beers without him. But when it came time to pay the bill, they discovered something important. They didn’t have enough money between all of them for even half of the bill!

And that, boys and girls, journalists and college professors, is how our tax system works. The people who pay the highest taxes get the most benefit from a tax reduction. Tax them too much, attack them for being wealthy, and they just may not show up anymore.

Man apparently survives 24 days in state of hibernation

A while ago I blogged about how long people can survive without water (max about 5 days). However, I have come across this article from the BBC about a Japanese man survived 24 days without food or water!

In 2006 while mountain climbing it seems he tripped and lost consciousness. Apparently “he fell into a hypothermic state at a very early stage, which is similar to hibernation”. When he was found “he had almost no pulse, his organs had shut down and his body temperature dropped to 22C”.

After being rescued he was “treated for severe hypothermia, multiple organ failure and blood loss” but made a full recovery despite his ordeal.

Pretty amazing story if it is true. Amazing things do happen.

Before and after satellite photos of our impact on the environment

This is an interesting gallery before and after satellite photos of mankind’s impact on the environment. They come from a new book called Fragile Earth and are pretty interesting. It can be quite sobering to see what a real impact we are having on our environments

This one shows a rainforest ecosystem around the Iguacu falls in South America getting nailed. Feb 1973 to May 2003

This is Lake Chad in Africa disappearing between 1972 and 1987 – largely due to irrigation projects. Things have actually gotten worse since the second photo was taken… I have blogged on this one before.

Finally, this is jungle in Bolivia getting turned into a major agricultural area.