The impressive three-story-tall sphere in the Comcast Technology Center opened to the public Monday morning.

Anyone can now step inside the mysterious pearly white globe to experience a free, virtual reality-like show that’s equal parts awe-inspiring, thought-provoking and nausea-inducing, according to early reviews.

Officially called the Universal Sphere™, the planetarium-style installation has been sitting mysteriously in the CTC lobby since the building opened last summer. In January, Philly Mag got the early word that it would house a Steven Spielberg-produced movie experience — and the rumor turned out to be true.

The interior of the 39-foot-diameter orb plays host to a short film called The Power of I. The gist? To “explore the power of ideas.”

In recent weeks, more than 4,000 Comcast employees and assorted guests took the attraction for a test ride. There’s a website where you can reserve tickets and explore the background of what you’ll see once inside.

Here’s what you need to know.

Do I need tickets?

Tickets are not required for the Universal Sphere, but only 25 people are allowed inside at once, so if you want to assure yourself and friends a spot, they’re a good bet.

Reservations are available same-day only, and you have to allow the ticket site to know your location (if you block the browser request you won’t be able to continue).

To reserve, you enter your email address, then the number of people in your party (up to four), then choose your 15-minute time slot. They’re available 10 a.m. to 5 p.m. Monday through Friday.

Otherwise, you can just show up and test your luck. Vernick Coffee Bar right across the way provides plenty of distracting bites and sips to make waiting more pleasurable.

Who can go in?

The experience is fully wheelchair accessible and service animal-friendly, according to Comcast. Audio and Closed Captioning devices are also available upon request.

How does it work?

When you enter, you’re seated on a raised dias that’ll move around as the movie plays. Think theme park ride — Universal Studios is one of the partners that produced the sphere (as evidenced by the name).

Once seated, the lights go down and the 360-degree dome that surrounds you begins flashing images on its screen.

What’s in the show?

The connecting theme of the production is the power of ideas.

Narratives follow the stories of “geniuses” throughout history — Beethoven, Confucius, Angelou, Earhart. At one point the movie zips you through a galaxy shaped like Albert Einstein’s eye, according to the Inquirer.

Another tack explores impactful documents of the United States, from the Constitution to Martin Luther King Jr.’s “I Have a Dream” speech to the Title IX legislation that outlawed gender discrimination.

Stories are told on a personal level for maximum impact, like that of Emily Whitehead, a young leukemia patient at CHOP who was saved with a breakthrough drug. “I had tears in my eyes” after watching the show, a Comcast staffer told NBC10.

The Inky advises caution for people who have motion sickness or other vertigo, as the experience is apparently pretty life-like.

What’s Spielberg’s role?

Reportedly a personal project of Comcast CEO Brian Roberts, the sphere took advantage of assets across the Comcast NBCUniversal network.

Steven Spielberg is listed as executive director of the short film. Talent from DreamWorks Animation, Universal Creative, Universal Parks & Resorts and Comcast Labs also worked on production.

Mychael and Jeff Danna, who won Academy Awards for work on Life of Pi, composed the original score. Narration is by Peter Coyote, who some might remember for his role as the scientist/government agent in E.T. (a Spielberg flick).

In a video message posted online, Spielberg says his goal for the show is for “everybody who experiences this to feel that they matter, that they count.”