An interesting Italian blog here dealing with some of the scientific questions behind contrails. Has some software for contrail forecasting
http://ilcielosuvicenza.blogspot.com/
It seems like he once believed in chemtrails, but then did some more research in them, specifically by taking detailed photos and finding the plane type and altitude.
Here's his page on calculations:
http://ilcielosuvicenza.blogspot.com/2008/10/questione-di-stima.html
(I use Google Translate to read the above pages)
http://ilcielosuvicenza.blogspot.com/
It seems like he once believed in chemtrails, but then did some more research in them, specifically by taking detailed photos and finding the plane type and altitude.
Here's his page on calculations:
http://ilcielosuvicenza.blogspot.com/2008/10/questione-di-stima.html
(I use Google Translate to read the above pages)