The video quickly went viral on the Internet. It had more than 1.8 million views on YouTube by Friday morning.
Selby's inspirational message included theme music from "2001: A Space Odyssey." He tells his fellow students about his dream of building the Iron Man suit and says anything is possible.
"If you want to change the world, you're at Georgia Tech, you can do that," he tells the incoming freshmen. "If you want to build the Iron Man suit, you're in Georgia Tech, you can do that!"
The widely viewed highlight from the speech is less than two minutes.
The Atlanta Journal-Constitution reports that in other parts of the speech, Selby offered practical advice for every new college student, including sit in the first few rows of class, get sleep, call mom, do laundry and apply for internships.
He also explains why he came to the Georgia Institute of Technology:
"I want to build the Iron Man suit," he says. "As cute as my application essays were, green energy and world peace can wait. I want to fly around the world in an impenetrable suit of armor dating Gwyneth Paltrow."
Selby, who is from the Phoenix area, is part of the mechanical engineering class of 2015.
Copyright 2013 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.