Slashdot Mirror
NASA Beams Hi-Def Video From Space Via Laser
An anonymous reader writes "NASA successfully beamed a high-definition video 260 miles from the International Space Station to Earth Thursday using a new laser communications instrument. Transmission of 'Hello, World!' as a video message was the first 175-megabit communication for the Optical Payload for Lasercomm Science (OPALS), a technology demonstration that allows NASA to test methods for communication with future spacecraft using higher bandwidth than radio waves." Last September, NASA's LADEE (Lunar Atmosphere and Dust Environment Explorer) showed that they could supply a lunar colony with broadband via lasers.
NASA Beams Hi-Def Video From Space
Good god! Haven't they thought this through? Once the RIAA hears of this, it'll be the end for our space program!
There is a hunger issue at the city kennel with not enough funding to feed all the cats and dogs, so a lot of them get put to sleep, or get neutered at the least. In an ideal world you'd let all cats and dogs freely breed and provide each with as much food as they want, but once you end up with a few billion cats and dogs, and you're still living up to your principles of free breeding and the right to feed, you're facing a few trillion of them, and the costs of living up to your principles sooner or later come due. Life has an immense capacity to breed and proliferate, and only a resource limit, such as availability of funds and food put a limit on the population. In this sense, in the sense of lack of self control in population management, starving is a necessity that sooner or later comes due. You simply cannot teach and explain to people to stop hitting that booty when the kids you already have are starving. Life reproduces irregardless of resource limits, and whatever will be will be, we face the tomorrow boldly, head on, we'll figure out a way later, or starve, but we have to keep breeding no matter what. Starving is a necessity with such attitudes.
Why is a laser better than other forms of EM radiation like radio? Channel capacity depends not just on the frequency-limited bandwidth, but also on the ratio of signal to noise. Increasing signal strength or reducing noise will improve bits per second. (The Nyquist limit of twice the frequency bandwidth only governs frequency modulation, not amplitude modulation.)
Assuming background noise is constant, a laser's (much) better focus means more of the energy pumped into the signal reaches the destination, rather than spreading out and being lost to space. More signal => better signal to noise ratio => higher channel capacity for a given frequency bandwidth.