also could anybody give me a link or tell me how difficulty is determined?
Difficulty is adjusted every 2016 blocks. The intention is that it will take the entire network 10 minutes (on average) to find a block, so finding 2016 should take 14 days. If solving the next 2016 blocks takes only 7 days, difficulty will (roughly) double.
Whether this is a scam or not, I wouldn't buy any mining device that won't be available for four and a half months. There's no way of telling how high the difficulty will climb by then.
At the current rate, it's raising 30% every 11 days. That's 12 difficulty adjustments until February 24 (if they deliver on time), giving a difficulty of 4.4 billions.
yes but 2 TH/s is 2 TH/s it would manage those changes until february or you think it couldnt?
The earnings per GH/s are inversely proportional to the difficulty. Right now, it's at 189 millions. A 2 TH/s miner at a difficulty of 4.4 billions should generate the same income as a 86 GH/s miner at the current difficulty.
Yes but does diffulty also lower down if noone mines or if it takes more than 10 minutes for a block to be found?
if so then when difficulty reaches such extreme numbers I suppose that most of the community will drop out from mining... thus forcing difficulty to low down again then attracting old miners to return difficulty raises again eventually people will drop out.. etc etc wouldnt it be a good idea to have a 2TH/s machine and "come in game" when difficulty raises so high making people to quit and gaining profit by mining while the difficulty level drops (because of less miners in the game) ?? and then take a brake again when people come back and raise the difficulty level?
The numbers aren't extreme, they are quite simply what they are.
You seem to be labouring under a few misapprehensions here, the only time anyone is going to stop mining is when it starts to cost more to run the mining equipment than it ever has a chance to recover, in other words when the rate of difficulty increase exceeds the ability to generate a btc payout and that point is still some considerable way off. Even at that point some will still continue to mine as there is a somewhat pervasive, almost religious belief that btc is somehow going to be worth thousands or even millions of fiat one day, and it seems to be rife. And as you alluded to, people think if they just keep going everyone else will stop which is just madness.
The difficulty won't reduce in any meaningful way at this stage, it is only the rate of difficulty increase that will fluctuate.