As you may be aware, Dr. Neil deGrasse Tyson is scheduled as a keynote speaker at the 2014 PLUS Conference, November 5-7 in Las Vegas.

Recently we at PLUS Blog had the chance to chat with Dr. Tyson about the universe, his personal philosophies and other topics that we found interesting. In case you missed it, you can view last week’s clip here.

In our new clip for this week, we ask Dr. Tyson:

“What one scientific breakthrough or widely held belief, that was later determined to be untrue, had the greatest impact on our understanding of the universe?”

Don’t miss your chance to hear Dr. Tyson speak live in November at Caesars Palace in Las Vegas – register for the 2014 PLUS Conference today.