Maybe this would be more appropriately titled how to get noticed or how to keep friends or something.. Because it's really about me thinking about exactly what people do that gets them noticed, remembered and likd by people around them. And when you realise what people are doing to get themselves noticed, you also realise what the other people are or aren't doing that gets them unnoticed. And if you're thinking this is just a joke, or "invisible? yeah right" then thin again. This is all real. It can be quite unsettling.
Being invisible is about no-one knowing you exist. Becoming a ghost. Unfortunately there's some sacrifice to be made. You can't have any friends. Friends aknowledge your existance, which is contrary to the purpose of this experiment.
Did you ever have a class at school where each student had to do a presentation to the group, and there was that one kid who stepped up to make his presentation and you wondered "He's in our class? Who even is he?" There's always the quiet one. He doesn't have any friends. He never puts his hand up in class. He's never around at break time. It's almost like he's invisible. You can learn from that guy. What does he do, or not do that makes him go unnoticed?
The next time you go into work or school or whatever it is you do, don't talk to anyone. Of course this is easier said than done. Sometimes you'll have to talk to someone. The professor may ask you a question. Your colleague might ask you for help. You might be required to answer a phone call. You need to keep acting normally in these circumstances. If you don't then you'll be remembered for doing something akward, different. That's not what you want to be doing. If a pier says hi as you cross her in the corridor, say hi back. If you ignore her, chances are she'll remember who as that jerk who didn't even say hi. However, don't initiate any interactions with anyone. Don't say hi to people as you pass.
Don't make eye contact or smile. If you have a normal or maybe slightly mopy expression and look at the ground or straight in front of you you won't get noticed so much. In the same fashion (get it? you will later) your overall appearance matters a lot. Don't wear any clothes that will get you noticed. Wear drab colours and unstylish clothes. Shop at M&S. (Ok, so I have a bit of a personal thing against M&S clothes for being too normal and boring, though right now that's perfect.) If you look unattractive then you have an advantage here, though beautiful people don't despair. You can simply neglect the numous hair products you usually use daily and wear less (read no) make-up. Don't wear too strong perfume or deoderant; you don't want a distinctive smell that people can recognise.
Don't hang around where people are likely to be. Don't hang around in the cantine. Go somewhere quiet to eat. Don't join any clubs or teams. You can do solitary things like go to the gym or pool, where you can quietly do your thing unnoticed. Inevitably you'll have to talk tosome people, such as a cashier, though keep your voice low, your tone flat and your gestures minimalist. Though don't talk like a robot or stand like a statue. Keep it normal.
You don't compel people to talk to you, you don't put yourself out there and you don't place yourself in situations where you're likely to be noticed. What starts to happen is that people stop noticing you. You begin to be able to walk around the workplace completely unnoticed. You'll be able to wander around, get a coffee, whatever, and people will see right through you.
The novelty wears off pretty quick though.