What blew up my Twitter feed lately? by BruceM

Question 10

Either of two answers is acceptable.

"Honestly climate change scares the heck out of me and it makes me so sad to see what we're losing because of it."

"Maybe you should learn some actual SCIENCE then, and stop listening to the criminals pushing the #GlobalWarming SCAM!"

"I dunno, man, I already went and got a PhD in [BLANK]. Seems like more than that would be overkill at this point.”

Name either the Australian scientist behind those first and last tweets, or her field that fills in the blank.

Katie Mack; astrophysics