Yesterday I posted a riddle about three black things:
These were the guesses:
— “The Steam launch button” (apparently because of the similar logo)
— “Keyboard keys”
— “Magnets!!! For sticking photos on the fridge!!! )))))”
— “Share buttons”
— “Disassembled headphones)”
— “3 x BlackBox”
Thanks to everyone who took part for the guesses. Special thanks to the good folks who knew what it was and didn’t kill the intrigue in the very first comment.
Attention, the correct answer.
The black things shown in the photo are beacons: radio-electronic devices that are installed indoors. The beacons transmit their identification number by radio. Mobile phones, iPhones or Androids, read this signal and determine their position indoors, provided that you enter the positions of the beacons into the phone. The photo shows beacons made by “Kontakt” (http://kontakt.io/), whose logo really does look a bit like the “share” button and the Steam logo.
You might think, why are these beacons needed if GPS technology already exists and is successfully used to determine a phone’s position in space? GPS has a drawback: the signal from satellites attenuates very strongly when it passes through the floors and walls of buildings. All you have to do is step under a roof, and the GPS receiver will show coordinates with a substantial error. So it is precisely to solve the problem of location (position determination) indoors that alternative technologies have been developed.