if i invent a time machine in the future and go back in time right now and give it to myself therefore eliminating me

Question: if i invent a time machine in the future and go back in time right now and give it to myself therefore eliminating me having to invent it why dont i have a time machine right now???????
- Keywords:
  future,
  invent,
  machine,
  time
Asked by stewieadam to David, Luna, Mark, Melanie, Probash on 24 Mar 2011 in Categories: General.
- David Pyle answered on 24 Mar 2011:
  
  Because you have just thought of a logical reason why time-travel would not be possible!

Question: if i invent a time machine in the future and go back in time right now and give it to myself therefore eliminating me having to invent it why dont i have a time machine right now???????