[przemub]

The sensor bar is passive - it's just two infrared diodes so the Wiimote can get an idea of its own position.

So you can replace it with candles as they emite infrared light as well!

[mock-possum]

I always thought it was hilariously similar to how to old NES zapper worked - the sensor was in the gun, it decided what you ‘hit’ based on what the sensor saw when the tv flashed. I think it was an early instance of me recognizing an engineering ‘hack’ - instead of the target reporting whether it had been hit, it was the gun reporting whether it thought it had hit the target.