The earth may have moved for Melbourne residents last night but experts say they didn't feel a thing. Geoscience Australia, the national body which measures earthquakes, said there was no evidence of an earth tremor in Melbourne, despite radio reports of one this morning. However, they said it was possible a sonic boom caused the shaking. Given the large number of residents who reported feeling a rumbling shortly after 3am (AEDT), a Geoscience Australia spokesman said it appeared something had occurred but no one was sure what.