This is what the company is exploring via Project Soli, an experimental hardware program which uses miniature radar to detect movement, and which recently won approval from the FCC for further study.

Imagining exactly how this tech will be put to use is tricky, but a group of researchers from the University of St Andrews in Scotland are exploring its limitations.

In a paper published last month, they show how Project Soli hardware can be used for a range of precise sensing tasks.

These including counting the number of playing cards in a deck, measuring compass orientation, and even discerning the specific configuration of a stack of Lego bricks.

All this is done using the delicate radar readings from Google’s hardware, which the researchers incorporate into a system they call RadarCat.

As with radar used to detect aircraft, the sensors fires harmless electromagnetic pulses at a target object, some of which are bounced back.

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