Earth

Earth, home planet of a preFTL sapient race of primatoids who call themselves 'humans', numbering approximately seven billion. Estimated time of arrival to the galactic stage: about 100 of their years.   An unscrupulous FTL race of reptilians used body modification technology to infiltrate their society unbeknownst to them,attempting to subtly influence their politics to be more conducive to accepting vassalization once they acquire FTL tech. Other civilizations have been unable to assist the humans since their planet lies within Reptilian borders.   The humans have a device called the Large Hadron Collider, which is an accelerator that smashes subatomic particles together in an attempt to randomly discover new physics. At its current settings, it could help discover the method to accumulate negative mass for FTL travel, but it would realistically take 100 years to obtain a 50% chance of that at the current rate. Once discovered, the physics application is easy enough to implement within a week with their current technology level.   ...   The humans discovered it early! A reptilian peon panicked, demorphed and bit apart a scientist working at the LHC. He was then captured by the humans and has been successfully interrogated. His superior alerted their homeworld and their fleets will arrive in six earth days for an invasion. Our alliance has declared war and the federation fleet is set to arrive in six and a half of their days.