WiFi, Cellphones and us - Wireless Frying?

In its entry on the microwave oven wikipedia says,

Cooking food with microwaves was discovered by Percy Spencer while building magnetrons for radar sets at Raytheon. He was working on an active radar set when he noticed a strange sensation, and saw that a peanut chocolate bar he had in his pocket started to melt. Although he was not the first to notice this phenomenon, as the holder of 120 patents, Spencer was no stranger to discovery and experiment, and realized what was happening. The radar had melted his candy bar with microwaves. The first food to be deliberately cooked with microwaves was popcorn, and the second was an egg, which exploded in the face of one of the experimenters.

So, thats how back in 1945 Spencer unwittingly discovered that his radar could cook him and his popcorn as well ;-). Anywayz, over half a century on, we're literally swimming in a sea of microwave signals. TV towers, telecom repeaters, cellular networks ... and 802.11 - the relatively humble WiFi.

What prompted my short study and this post was a recent BBC report WiFi: Why Worry?
lots of blog noise and the fact that I have a WiFi router in my house.

I've bulletted the 'givens' as follows:

1. Natural Electromagnetic radiation exists around us, the most obvious being sunlight (visible and otherwise).

2. There have been studies on the thermal as well as non-thermal effects of EM. The relative biological 'danger' depends on (a) The frequency (b) The power (c) Duration of exposure and an implied (d) Distance from source.

3. Following are some stats I could collect:

a. WiFi normally operates at around 2.4 GHz, 100 mW peak power? typically at 50 ft range.

b. A cellphone operates 800 MHz to 1900 Mhz with upto 2W peak and .25W average at typically 0 ft range!

c. A cellphone tower operates at a similar frequency range, power 20 to 30 W continuous at 100 ft plus range.

d. Microwave ovens emit around 1000W peak though human exposure due to typical leaks out of the box are less than .1 W.

On one hand there are many a scare sites that say - "look, if this stuff can 'pop' corn and break down DNA structure of bio materials inside a petri dish - it can fry you too! So cover yourself with anti-EMF paint and wear a Aluminium Foil Deflector Helmet"

Here's a seriously fun study that some MIT dudes conducted with the AFDH.

At the other extreme are many 'studies' (some say - industry sponsored) as well which conclude that normal human exposure to these is 'fine' since they haven't literally found anyone 'directly' fried or even made cancerous directly through WiFi or cellphone! - at least statistically.

So, where does that leave us? The usual middle ground for now - avoid em as much as possible - for instance - by not gluing the cellphone next to ones ears for over a few mins, not fixing the WiFi router under the office chair (does someone do that?) and not drying a cat inside the microwave oven! ;-)

Jan Shatabdi Trivandrum Ernakulam - the invisible emergency hammer.

Train journeys are seldom uneventful. Yesterday, Jayadev and I went on a one-day business trip to Ernakulam (Kochi) and back to Trivandrum (Thiruvananthapuram). This was my first trip on the Jan Shatabdi Express (the link says how these trains came about). Though conceived as a 'cleaner', faster and slightly costlier service, it is does not even come close to what would internationally be considered fast and clean. A google search also drew out this undated document lamenting its low occupancy rate (? - our train was pretty full; the doc seems to have been written in 2003)

Anyways, this train is better than the average Indian 'train' on all counts (more on that later). Though low cost carriers like Air Deccan may soon threaten its existence - there are quite a few who'd prefer to travel well grounded :) So the good things first:

1. Pretty fast with just a few stops and pretty comfy luxury bus kinda push back seats.

2. GPS / GSM (?) based station display which shows ETA at the next stop, the time we passed last waypoint etc.

And now the bad things:

1. Whoever designed the air-conditioning system, gave no thought to the noise it made! It made a constant shrill high pitched tone almost throughout the journey! Unfortunately, no one else seemed to share my sensitivity towards this sound - they seemed happily unaware of the sound that was driving me crazy.

2. Tea / coffee / snacks. Although the entire journey hardly last a quarter of a day - it does make one hungry. I was pleasantly surprised to find Nescafe coffee vending machines and microwave ovens inside the compartments (Now that sounds like a first inside indian railways). However, I was told that these had just been there for a few weeks and might take months to get functional. I sure hope railways can make it operational asap.



3. Now for the (dangerously bad) icing on the spoilt cake ;) This is something that we Indians are pretty good at - being terribly unprepared for emergencies. The pictures are self explanatory. However, for those who cannot see the writing on the image clearly, here's the text - "HAMMER FOR BREAKING THE WINDOW GLASS DURING EMERGENCY". The only problem is - there is no hammer inside the beautifully sealed enclosure (or it is of the invisible kind). A quick glance revealed that even the next compartment had a non-existent emergency hammer.


Now, I do not know for sure how much difference that hammer might make in an emergency, but I sure do hope and pray that no-one gets into such a situation!