For Science!6 Wondrous Technologies We Take for Granted (and Complain about)For Science! - RSS 2.0
3. Digital Cameras
"Ugh, this picture came out terribly."
Whether it's your smartphone's camera, your webcam, or even - gasp - an actual camera, this tiny device is able to capture and store still and moving images at the press of a button. Unlike older cameras, digital cameras use electronics rather than chemicals to process the image - and it's ready for viewing instantaneously.
Digital image sensors turn incoming light into discrete digital signals. The number of pixels in the sensor determines the camera's pixel count, so an 8 megapixel camera has 8 million pixels. Like in a traditional camera, a digital camera uses a diaphragm and shutter to focus the correct amount of light onto the imager - in this case, the sensor - and the more light a given pixel receives, the larger the value that is digitally assigned to it. The sensors themselves are only sensitive to the intensity of the light - how dark or bright it is - and not the color, so additional color filters must then be used to process color information. In typical cameras, overtop every pixel is a single color filter than can measure the intensity of either red, green, or blue light (determined by targeting specific wavelengths of light). These color filters are arranged in a mosaic pattern, and digital processing then interpolates these discrete color data points into a full-color image.
So the next time you complain about how that selfie turned out, try hiring an artist to follow you around and paint your portrait.
"Ack, stupid GPS thinks I'm on the wrong street."
Whether it's a service on your smartphone or a dedicated device, GPS means future generations will never bother to learn how to read a map. A paper map, not a Google Map.
Standalone GPS uses satellites and software to determine your location data. GPS satellites are continuously transmitting their current position and the time of transmission via radio signals. Your GPS receives these messages and is able to determine your distance from the satellite based on the current time and the transmitted data: the satellite's position and how long ago the message was sent. Since we know the speed at which the data travels, your distance to the satellite is easily calculated. If that distance is, say, 20,000 km, that means you can be anywhere along the outer edge of a 20,000 km sphere around the satellite. That's why your GPS pulls data from four satellites to determine your position: the point at which four spheres intersect.
Assisted GPS, found in most smartphone GPS devices, additionally connects to an internet network to deliver faster and more precise results. It can take 30-40 seconds for a standalone GPS to "find" the nearest satellites and start giving you positional information. Assisted GPS will download the orbital position of GPS satellites to cut down on that time, and a lot of the processing can be offloaded to the server - which will have a more powerful computer than your mobile device.
The next time you complain about your GPS, consider that you're accessing equipment floating around in space - you know, that place that astronauts visit?