Time Is Distance
Have you noticed that during a thunderstorm, you hear the sound sometime after you see the light? The reason is that sound waves travel much slower than light waves. We can estimate our distance to the storm by measuring the delay between the time that we see the thunder and the time that we hear it.

Multiplying this time delay by the speed of sound gives us our distance to the storm (assuming that the light reaches us almost instantaneously compared to sound). Sound travels about 344 meters (1,130 feet) per second in air. So if it takes 2 seconds between the time that we see the lightning and the time that we hear it, our distance to the storm is 2 x 344 = 688 meters.

We are calculating the distance to an object by measuring the time that it takes for its signal to reach us. In the above example, the time that we see the lightning is the time that the sound waves are generated in the storm. Then we start to measure the delay until the time that we hear the sound. In this example, the light is our start signal.

Google provides navigation applications based on Gglobal Positioning System (GPS) is free for smartphones that use the Android platform. Application called Google Maps Navigation will be available first on Motorola Droid which will be released for Verizon in the U.S., November 6, 2009.

Compared to general navigation applications, Google Maps Navigation has a number of advantages. New applications that can work on Android operating system 2.0 is not only provides standard features like GPS navigation applications display three-dimensional maps and directions with voice guidance.

However, the application also provides other features such as voice search, traffic information, satellite map, "street view", to photograph the object goals. In fact, with this application, users can find routes to a number of important locations such as gas stations or restaurants.

Google Maps Navigation presence is expected to be a major competitor navigation solutions are already widely available on the market. For example an application made by Garmin or TomTom. With that one application, call Verizon Motorola Droid as a challenger to Apple iPhone and BlackBerry-made Research In Motion.