This section is currently under construction. Please bear with me whilst I organise my favourite science & nature links for publication.
SDR is a ‘software-defined radio’. This one at the University of Twente covers shortwave transmissions 3-30MHz, and has a number of controls which a normal receiver would have like volume, filter width, squelch, noise reduction, etc, and also a visual display of the signals you’re receiving. You can scan up and down the frequencies to your heart’s content using the mouse wheel, and log your discoveries and/or record them as audio files. (I think you have to register for these… I may have to do that!). Click http://websdr.ewi.utwente.nl:8901/ to give it a try.
Wikipedia articles on space & time
Space elevators – a quick way of getting into space with minimal power outlay?
Dyson spheres – megastructures in space – a possible solution to overcrowding Earth?
The Oort cloud – what’s lying on the edges of our Solar System?
The Arrow of Time– a one-way street?
Tau Day – Pi Is Wrong!