Zero Gravity? How does that work?
Posted on Tuesday, April 28, 2009
The first question people ask when I tell them about my wedding is: “Zero Gravity? How does that work?”
Apparently, not everyone has heard of the vomit comet. Starting in 1959, NASA ran flights which allowed passengers 30 seconds of weightlessness at a time. These were primarily research flights for scientists. The movie Apollo 13 was filmed in such a plane. In 2004 the Zero Gravity company started offering weightless flights to the public.
The passengers don’t achieve true “zero gravity” in physics terms. Apparently it’s referred to as microgravity or simulated zero gravity, because technically, it’s not zero gravity. Here’s a discussion of the terminology.
The plane flies in a series of “parabolic arcs,” which means it kind of flies in a roller coaster hill-like pattern:
So, just like riding a roller coaster, you feel weightless coming down the hill:
Why do you feel weightless at that point? I never took high school physics, and neither did Noah, but I learned a lot from 3-2-1 Contact, which is also where I first heard about the Vomit Comet. Astronauts in orbit are not really “weightless.” They have the same mass as always, but they don’t feel gravity. Astronauts are in a state of free fall, falling towards the Earth at the same rate as their shuttlecraft. They are still effected by gravity – Earth’s gravity keeps them in orbit.
What happens on a roller coaster, in the Zero G plane, and on a space shuttle is that the contact forces you usually feel are removed. Here is a really good article about contact forces. Basically, when you sit in a chair, the chair is exerting a force on you, and you are exerting force on the chair. If you and your chair are suddenly dropped from a great height, like on the “Power Tower” at Cedar Point, you and the chair are falling at the same rate, so you’re no longer feeling the contact force.
In the Zero G plane ride, the passengers and plane are falling towards the earth at the same time, so with the contact force removed you just float around in there.
Our scientist friends have cleverly suggested we could just get married while sky diving, because technically, it’s the same thing. However, lots of people have had skydiving marriages. We want to be the first couple to get married in simulated zero gravity. Besides, my dress is made for space, and this way the wind won’t mess up my hair.