It took me weeks to go and see Gravity, and I wasn't sure why.

Everyone I know said it was amazing. That it was in the pantheon of 2001: A Space Odyssey. That it was the first movie that truly used 3-D as it was meant to be used. So I entered the theater with high hopes and a nagging feeling that there was something about the movie I wouldn't like.

At first I was holding back, but then–slowly–I was drawn in. Sandra Bullock was extraordinary, George Clooney a wry old codger of a seasoned astronaut. But then I found this feeling coming over me . . . gravity is important.

Not the movie, the scientific theory.

It wasn't that I was learning this from the movie, though the movie made that point over and over again over the 90 minutes of screen time.

It was me.

And then I got it. Gravity has sold some $220 million in tickets, with 80% of that for 3-D showings–meaning a $20 ticket price. It's a hit–and hundreds of thousands of people will see the film. But almost none of them have experienced life in zero gravity, and until you do it's hard to explain it. Gravity is awesome, and life without it–after the novelty–is really hard.

Really.

It isn't that floating isn't cool, it is! But so much of what we do requires things to stay put, our ability to walk or smell food. And things like going to the bathroom get very complicated very fast.

And I know, because I've been in zero gravity. Weightless. Free. Floating in midair. It's a feeling all entrepreneurs know very well–and one all aspiring entrepreneurs should know better. And now they can!

Image courtesy of Steven Rosenbaum

And you can experience it too–if you've got $4,950 to shell out for the day-long zero-gravity experience. It's frankly a bargain for those of us who grew up telling their friends they wanted to be an astronaut, but may not be able to get a seat on the space tourism flights that are currently priced for zillionaires only. The flights are run by Zero Gravity Corporation, a privately held space entertainment and tourism company which says its mission is "to make the excitement and adventure of space accessible to the public."

The experience is extraordinary, a once-in-a-lifetime experience in weightlessness.

The trip begins with a training session, explaining how the specially modified Boeing 727 will fly in parabolic arcs that are performed to create a weightless environment. The result is a zero-gravity experience that allows you to float, flip, and soar without gravity.

Here's how it works. Before starting a parabola, G-FORCE ONE flies at an altitude of 24,000 feet. The pilot then pulls up, gradually increasing the angle of the aircraft to about 45° to the horizon reaching an altitude of 34,000 feet. During this pull-up, I felt the force of 1.8 Gs. Next the plane "pushes over" to create the zero-gravity segment of the parabola. For the next 20 to 30 seconds everything–including me–in the plane was weightless. This maneuver was repeated 12 to 15 times, each taking about 10 miles of airspace to perform.

In addition to achieving zero gravity, G-FORCE ONE also flies a parabola designed to offer lunar gravity (one sixth your weight) and Martian gravity (one third your weight). This is created by flying a larger arc over the top of the parabola.

And while I know you're thinking that it sounds a bit nauseating, it's not. We did take an anti-nausea pill as a precaution, but I found the whole experience to be exhilarating and strangely calming.

The whole operation is professional, safe, and delivered with military precision. G-FORCE ONE flies in a FAA-designated airspace that is approximately 100 miles long and 10 miles wide. Usually three to five parabolas are flown consecutively with short periods of level flight between each set.

So, sitting in the theater with 200 strangers and my 3-D glasses on, I was sure of one thing–for all of them, it was the first time they'd really considered what life would be like without gravity. For me, it was a nostalgic reminder of just how amazing it was.

And guess what: It made we want to do it again. A few minutes of weightlessness, awesome. Getting stranded in space like Sandra Bullock . . . doesn't seem like a whole lot of fun.

Check it out for yourself here.