>>> (I still can't figure out why you can use an oscilator to make radio 
>>> waves, but not light rays...)
>>
>> Lasers?
>
> I don't actually know how those work. I was under the impression that it 
> works by exciting atoms so that they emit photons - much the same way a 
> lump of iron glows if you put it in a hot fire. (But with some mirrors in 
> there to ensure the light only travels in one direction...)

Photons from a glowing lump of iron (or even an LED) have all different 
wavelengths and all different polarisations.  Photons from a laser all have 
virtually the same wavelength and polarisation, it's very different.

Post a reply to this message