We’ll all be wearing this in a year or two. (ERIC LONG AND MARK AVIONO//FOR LUCASFILM LTD.)

“Who is that guy walking down the street muttering to himself?”

“He’s got a BlueTooth headset,” your interlocutor responds. Taken word by word, this does not clear up the subject much, but at least it does not sound like the sort of thing you would make up out of thin air.

“Why is that man in dark glasses twitching his head around and muttering, ‘Jimmy, I know you’re just around the corner’?”

“He’s got the new glasses from Google.”

Yes, by the end of the year, Google will be selling glasses ($250 to $600) that can stream information to your eyes in real time. Stare at a bridge, and Google will give you information about the bridge. Stare at Sofia Vergara, and Google will become flustered and urge you to buy flowers for your wife.

You scroll and navigate when wearing the glasses by tilting your head. “We are told it is very quick to learn and once the user is adept at navigation, it becomes second nature and almost indistinguishable to outside users,” Seth Weintraub, a blogger for 9 to 5 Google, noted.

Nick Bilton at the New York Times reported: “The glasses will have a low-resolution built-in camera that will be able to monitor the world in real time and overlay information about locations, surrounding buildings and friends who might be nearby, according to the Google employees. The glasses are not designed to be worn constantly — although Google expects some of the nerdiest users will wear them a lot — but will be more like smartphones, used when needed....

“Internally, the Google X team has been actively discussing the privacy implications of the glasses and the company wants to ensure that people know if they are being recorded by someone wearing a pair of glasses with a built-in camera.”

Just a tad.

Next Apple is going to come out with a series of iTinfoil Hats, and then we’ll lose all our reliable markers of insanity. Not wearing pants? Could be a Microsoft thing. Talking about Martian invaders and space elevators? Must be an employee at Google Labs.

In order to establish their bona fides as Deranged People Without Fixed Abodes, those bearded men on buses will be forced to go to increasing lengths, trapping, killing, and eating pigeons before our eyes for us to stop listening to their tech advice.

Sure, on the surface, it sounds cool. That’s always how it starts. Regular arm or cyborg arm? Cyborg arm, every time! Regular eyes or Google glasses? Why even bother asking? Hive mind? Don’t mind if I do.

Sure, I have enough difficulty holding the attention of people who are wearing ordinary clunky glasses. “Hi,” I say. “I read this interesting article the other day about a new planet . . .

“Come on, Tim,” they murmur, “let’s go listen to the warm, rich sound of vinyl.”

Then again, this could be because I make the mistake of talking to hipsters.

Looked at one way, every new technology brings the demise of something. Politeness used to be a set of rules that allowed you to put up with the people in the room with you at any given time. With smart phones, you don’t need to. So much for etiquette! Once the smart phone became widespread, the only way you can get people to uphold anything resembling dinner-table etiquette is to kill them before starting the meal. Anything short of that, and they’ll keep trying to check Twitter.

The old ways are overrated. Lose an arm, and you can replace it with a cooler cyborg arm. Lose your cell phone, and the world ends.

All rules of etiquette are based on the outdated assumption that the people you are with at any given time are more interesting than the Internet. We know this to be false.

So now we’re turning into a group of people who twitch their heads (imperceptibly, of course), videotape our neighbors without their being able to tell, and constantly mutter to ourselves? That’s starting to move from Men Who Bother You On The Bus squarely into serial-killer territory.

The modern icon? Darth Vader, more machine than man, a guy who has never once seen his children through anything other than a futuristic cyborg helmet. I bet he’d love these Google glasses.

But hey, this is the future! It’s going to be great! Anyone who tells you otherwise is probably a deranged homeless person.