Despite the fact that the thing is way too expensive, Google Glass is all the rage these days. Google has recently thrown the device into the spotlight and basically declared it the next big thing after smartphones, so, needless to say, the Internet is paying attention.

If Google Glass wants to be successful, it needs the Internet. In more ways than one.

You see, the only way Google Glass can perform any of its much-hyped features is by connecting to a wireless network. But unless you're in a Wi-Fi hotspot, the glasses can't actually connect to the Internet on their own. The only way they can access a cellular network is if they're tethered to your smartphone via Bluetooth.

Before Google Glass was unveiled, there were rumors that it would be able to connect to 3G and 4G networks. Those rumors are dead at this point, since allowing that functionality would drain the battery extremely quickly.

However, there might be another reason why the glasses don't connect to cellular networks, and that reason might be cancer.

To be clear, no one's sure yet if cellular radio frequencies absorbed by the human body cause cancer, and the claim is very controversial. At the same time, the World Health Organization sees enough evidence to at least classify the frequencies as "possibly carcinogenic to humans." The U.S. Federal Communications Commission, too, is worried enough to outline limits on the number of frequencies phone makers can expose consumers to.

A 2010 study on the subject linked 30 minutes or more of phone use a day for 10 years to the development of brain tumors.

Other studies have filed contradictory results, but nonetheless: Do you think Google wants to potentially attach cellular network-connected glasses that beam carcinogenic radio waves into people's heads all the time?

For its part, a Google spokesman told Quartz that the reason there's no cell network connectivity has much more to do with battery power than cancer. "Considerations around power usage are much closer to the truth in this case. And note that RF limits apply even without a cellular radio," he said.

No matter what the health implications are, the lack of cell connectivity makes it hard to replace the smartphone in any significant way; it essentially means that users will need a smartphone on them when they go about their day even while wearing Google Glass. If it's not a health hazard, it's still at least a very expensive proposition.