Ultimately, it was unclear whether Noah’s machine worked but Jonas Kahnwald (Louis Hofmann) did get sent to the future. Also, Noah managed to travel through different time periods, suggesting the contraption did work.
For instance, in season one Noah visited Mikkel Nielsen (Daan Lennard Liebrenz) in hospital after the child showed up there when he first travelled through time.
Later, Noah was seen in other eras and even meeting with a young version of himself (Max Schimmelpfennig).
Some fans have wondered why Noah only took boys rather than girls, perhaps the simple reason could be: he felt less guilty.
Also, Noah was the father of baby Charlotte and by taking a female child, it may have triggered painful memories of his own loss.
Dark seasons 1 to 3 are streaming on Netflix now