Author: navin

Global dimming

You’ve heard about global warming, but did you know about the (possibly more serious) issue of global dimming?

The sun keeps us (i.e. the earth) warm. And gives us all energy and life. And over the last 50 years, the amount of sunlight reaching the earth’s surface has reduced by about 1 to 3% per decade.

And the culprit is air pollution. Some of the pollutants absorb the sunlight before it reaches us, while others reflect it back into space.


Golden Gate Bridge with California‘s characteristic brown cloud in the background — the most likely cause of global dimming. Photo CC 2004 by Aaron Logan

There are a number of interesting issues related to this:

  • Global dimming might be masking the effects of global warming.
  • For the few days after the 9/11 terrorist attacks, temperatures were 1 to 2 degrees higher than average in the US. Due to fewer jet flights, resulting in fewer aircraft contrails (aka vapor trails).
  • There exists something called the Asian Brown Cloud which sits over India and much of South and South-East Asia which is being blamed for a lot of things.

I found out about this from this Straight Dope article.

Fast Food: Ads vs. Reality

These guys bought a whole bunch of fast food items, took photographs of them, and then compared them to the photographs of the same items in ads.

A reader over at boingboing has this to say:

I worked (briefly) in the photogoraphy studio of one of the biggest ad agencies in NYC. They paid a professional “food stylist” around $2000 a day to make the food look like that. Every golden sesame seed or drop of crystaline dew was hand placed. That maoynaise isn’t mayo, it’s hair gel and that chicken looks so good because aparently everything looks yummier when it’s been sprayed with laquer. A lot of that “food” isn’t food at all and the stuff that is food has been treated with more chemicals and “tricks of the trade” than most super models.

How to make great powerpoint presentations

Marketing Guru Seth Godin has this insightful post on the right and the wrong way to make powerpoint presentations. The basic idea he espouses is that the powerpoint slides should be used to sell your idea emotionally. Don’t put facts and figures and numbers – that can go in the document that you leave behind.

Talking about pollution in Houston? Instead of giving me four bullet points of EPA data, why not read me the stats but show me a photo of a bunch of dead birds, some smog and even a diseased lung? This is cheating! It’s unfair! It works.

He goes on to give a bunch of DOs and DONTs which are worth thinking about. For example

Sound effects can be used a few times per presentation, but never use the sound effects that are built in to the program. Instead, rip sounds and music from CDs and leverage the Proustian effect this can have. If people start bouncing up and down to the Grateful Dead, you’ve kept them from falling asleep, and you’ve reminded them that this isn’t a typical meeting you’re running.

Read the whole post.