How dose this work??

I was just over at a friends house and he's got like three plants all under a foot high, all budding..

He doesn't use any lights or ventilation.. He just puts them in his window..
How the hell are they even alive? And how do I keep my plants short like he dose?

Any help appreciated

since he is only putting them in the window they are being restricted to something like 14 hours of daylight, 8 of which might be full sun, so yeah why wouldnt they be alive, also if he only has about 3 cubic feet foliage, he produces enough co2 in a couple hours to feed them for the day,

you want short plants give them tons of light up close and reduce veg period by going straight to 12/12