Some people are very concerned that radio wave power coming from radio transmitters’ antennas will harm people. In particular people are troubled by mobile phone masts causing long term health problems when they are near to their homes.
I just want to make it clear how much a transmitter’s power diminishes as it spreads out from a transmitter. I’m sure some feel it must follow a simple linear law such as:
double the distance and get half the power,
triple the distance and get a third of the power,
quadruple the distance and get a quarter of the power.
When in fact it follows an inverse square law which is nonlinear and gives this type of result:
double the distance and get a quarter of the power,
triple the distance and get a ninth of the power,
quadruple the distance and get a sixteenth of the power.
This means the power (and damaging energy) is much lower than might be expected at any particular distance. Even within a short distance the power can drop considerably.
At least one of my other posts How Distance Reduces The Power of Radio Waves (not yet published) requires an understanding of mathematical proportionality. In particular it requires an understanding of Inverse Proportion. So I have written this article to try and clarify it. It gives an explanation of the two types of proportion, otherwise known as variation, which are:
Inverse Proportion otherwise known as Indirect Proportion.
This was brought to light by APEX NEWS on 4th January 2012 as follows:
One of the signs at the Princesshay shopping centre in Exeter informing shoppers that their mobile phones are being monitored.
The popular shopping centre has been accused of using Big Brother tactics after it was revealed it was using stealth technology to track the movement of shoppers via their mobile phones – without their consent.
Human rights organisations are outraged that bosses of Princesshay are using the technology called FootPath to secretly track shoppers’ movements.
Customers receives no warning that their mobile phone signal is being monitored bar a small sign on the premises.
Neither do they receive an option to ‘opt-out’ of being scanned.
Customers on all networks are scanned by Footpath, and no current mobile phone has a ‘defence’ against such scanners.
The only way to be safe is simply to switch off. – APEX NEWS
Here’s a situation where there is a tendency to think, “I don’t like the sound of this.” See articles in the mainstream press about specific shopping centres which monitor mobile phone movements, e.g. Mail Online,The GuardianandThe Telegraph.
However they could monitor the movement of pickpockets and shop lifters.
If you like that idea you might want them to record personal data sufficient to help them ID the criminals.