So i was thinking if i send a bitcoin transaction without the miner fee or a very low fee what will happen ? would i get the coins back eventually ? or they will just stuck there forever ! and if that happened how to do that double spend ?
Bitcoins never go into space. You will either get the transaction returned or it will be included in a block.
no, there is no "transaction returning" in bitcoin. on paper it MAY be possible but in practice when you send a bitcoin transaction it will stay out there forever until it either confirms or becomes invalid (like by double spending) and gets rejected.
to OP if you want to do such a thing make sure to mark it as RBF so that if you changed your mind you still have an "easier" option to solve the problem.
All the above bullsh*t posts aside your bullsh*t is something entirely new, who the fu*k taught you this? when a transaction doesn't get confirmed after a while it will be as if you never sent it at all meaning it will be unlocked/ back to your wallet.
I don't know if people are getting dumber or what?
i don't understand the reason for all these insults! if i am wrong then feel free to prove i am wrong.
and no your "after a while" was increased from 72 hours to 336 hours or 2 weeks and there will always be a node out there that has your transaction in its mempool and is broadcasting it so it propagates through the network and every node will have it at all times.
there is no "as it it was never sent either". people are either using SPV or web wallets in which case they have no control over what happens and have to stick to methods such as RBF or simply double spending.
or they run full nodes and have control on what they broadcast in which case they can
manually "abandon" the transaction and make a new one, it doesn't happen on its own. it will stay in your node as your transaction that you keep broadcasting and in your wallet it will stay as spent.
even if they do that, the network doesn't have to accept the new transcription. when you rebroadcast the double spent transaction the nodes which have your previous tx will reject your new one because it is a double spend.