Why Siri Likes the Weather on iPhone 4S and Not on Older Devices (Video)

A re-opened teardown analysis reveals one of the reasons why Apple won’t have Siri on devices that are older than the iPhone 4S. As it turns out, the phone has a special little piece of hardware that the assistant requires to know when you’re addressing it.

Matt over at iFixit explains that during their original teardown they “noted that the new iPhone had a rather unusual-looking black component next to the ambient light sensor.”

“We didn’t make much of a fuss about it since we were knee-deep in disassembly pictures, but the little black box certainly piqued our curiosity,” Matt writes.

“Now that the teardown is wrapped up, we’ve re-opened the mystery and made a neat discovery about the 4S: that black component is an infrared LED, and the little bugger almost always wants to know if you’re nearby.”

The part ensures that Siri is running at full throttle. For example, when you pick up the device, it’s ready to listen to your command.

“Thus, whenever you raise the iPhone 4S to your face, Siri is ready to take orders,” the tinkerers at iFixit explain.

That’s not going to happen with the iPhone 4, and certainly not with the iPod touches which have inferior microphones.

A video demonstration featuring the group’s female member (MJ) is embedded below.

As MJ puts it, “mystery solved”. If there was one thing that helped Apple justify Siri’s ties to the latest generation of iPhones, this was it.

Sure, you can still call it a marketing move. After all, what’s keeping the company from updating the iOS on older iPhones to have the IR sensor work overtime, just like on the iPhone 4S?

Nothing, except maybe an urge to sell as many of these Siri-exclusive iPhones as possible. Or perhaps there are other hardware limitations that we’re not aware of. Apple doesn’t say. So we’ll just have to trust they doing all this in good faith.

Matt ends his blog post with a little clarification for those who may be concerned that their iPhones are emitting radiation that could be harmful to their bodies.

The truth of the matter is that IR doesn’t pose that big of a threat: “Infrared light is non-ionizing, meaning it is a low-frequency radiation, lacking the energy to influence changes in DNA.”

But that doesn’t mean you should’t wear a tin foil hat if you think it looks good on you.