As we reported yesterday, Twitter was the home of a very entertaining exchange in which a an astrophysicist sent a climate change denier to the burn unit after he suggested she should go and learn some 'actual science'. 

Many suspected that would be the last Dr. Catherine J. Mack, AKA @AstroKatie would ever hear from Gary. Fortunately for us though, Gary decided to come back for a second helping. 

After taking 2 days to come up with a sufficient comeback, Gary plumped for suggesting that Katie should get a refund as she was severely lacking when it came to the 'most basics of science'

Well Gary, you can argue with Katie all you want but a PHD paid for in part by Princeton University is hard to argue with. She knows what she's talking about.