With worldwide mobile subscriptions estimated to be around 7 billion in 2014, cell phones have become a universal and indispensable tool for modern life. With a cell phone, you can talk to anybody on the planet from almost anywhere. But do you really know how your cell phone works? In the most basic form, a cell phone is essentially a two-way radio, consisting of a radio transmitter and a radio receiver. When you chat with your friend on your cell phone, your phone converts your voice into an electrical signal, which is then transmitted via radio waves to the nearest cell...

The mobile device landscape has dramatically changed during the past ten years. As a popular wireless technology, Wi-Fi uses the radio-frequency bands of 2.4 and 5 GHz for data exchange among wireless devices. Devices that transmit Wi-Fi signals are not just commonplace, they have become an essential part of our lives. So, it’s only natural that the biological and health effects of these devices have become the subject of many on-going scientific studies. While the research community is performing scientifically rigorous studies and carefully weighing the evidence, five Danish ninth-grade school girls have taken matters in to their own hands....