Whilst having an e-chat with my girlfriend I jokingly pointed my TV remote controller at the webcam and pressed the mute button. To my surprise I could see the small bulb on the front of it flashing. When I looked at the bulb directly and pressed the buttons I couldn't see any flashing. Why is this?

I turned my tv on this morning to find that none of the remotes worked, (digi box and tv) then after two minutes both started working at the same time, I was wondering what could have caused this.

I turned my tv on this morning to find that none of the remotes worked, (digi box and tv) then after two minutes both started working at the same time, I was wondering what could have caused this.

What impact can this have on how they work or on the circuitry inside the remote control itself?

These particular batteries have been in use for more than 12 months, so they may well be nearing the end of their useful lives.

Nia and Steven Faulder, by email, no address supplied

The remote control contains an infra-red LED which emits a coded pulse train in a single wavelength to a spectrally matched receiver.  Since LEDs are available at wavelengths throughout the visible spectrum, and into the ultra-violet, why is infra-red used exclusively for remote control?  I remember once having a TV that had an ultrasonic control so it's clearly not the wavelength that's important, and it would be useful if the controller emitted, say, yellow light as you could see it was working.....