View from the root top of the Tate Laboratory of Physics at the University of Minnesota on Friday, Oct. 10, 2014. (Pioneer Press: Juan Pablo Ramirez)

The graduate students who run public-viewing nights at the Minnesota Institute for Astrophysics assume the public knows very little about the cosmos. This is a good thing, since what I know about the origins of the universe can be summed up in the theme song from the sitcom "The Big Bang Theory."

Our whole universe was in a hot dense state.

Then nearly 14 billion years ago, expansion started. Wait ...

I recently took my 12-year-old son to the observatory on top of the Tate Laboratory of Physics on the University of Minnesota campus, where every Friday night during spring and fall semesters, astrophysics teaching assistants give a short talk and let the public look through the 19th-century telescope.

My son is not one of those kids who is captivated by outer space, but he likes science, and I knew he would be interested in the antique scope.

"We do what we can to bring astronomy to the public because it's one of those sciences that captures the imagination," said graduate student Melanie Beck, whose interest in astronomy was sparked by seeing Comet Hale-Bopp as a child and who now heads up astrophysics outreach programs.

The Friday topics range from asteroids to the Big Bang, from spacecraft and satellites to the life and death of stars.

"People love to hear about galaxies, and they love to hear about colonizing Mars, and they always love black holes," Beck said. "Even if the topic is not about black holes, people always ask questions about black holes.

The night we were there, the subject was the most-distant galaxies. About 40 people, including college students on date nights and a few families, sat on hard chairs in a classroom with old radiators and a poster of the periodic table on one wall. It felt like Cosmos 101.

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At UMN lab, use 100-year-old telescope to see billion-year-old stars