Posted on Leave a comment

Simulating gravity (or lack thereof) on film – an experiment to demonstrate our perception of weightlessness.

Peter Diamandis in ZERO-G

Simulating Gravity on Film

Zero-G refers to weightlessness and means “zero g-force” not “zero gravity” as some would believe. It’s most commonly envisioned as astronauts floating around in space. You can experience zero gravity in a free-falling airplane too and in fact, astronauts use these free-falling planes to train in a weightless environment.

At 300 miles above the Earth, where the space shuttle glides, the pull of gravity is only about 15% weaker than it is on the Earth’s surface. While it may not seem like much of a difference, weightlessness is not simply the absence of gravity. Rather, it can be thought of as the gravitational force acting on an object from all sides equally.

In this experiment, we will manipulate the direction of gravitational force but film it in such a way that it appears as if the direction has not changed. This will create a fascinating illusion, making objects appear weightless as they climb walls and float around in our magic box.

Filming the inside of a cardboard box

We will build a box with a stationary mounted camera and light, both pointed inside the box. This way, even if the box is moved or turned upside down, the camera’s viewpoint remains the same. By doing this, we can change our point of view and feel like we are inside the box looking at its walls, unaware that the box is being moved around. Just wait, the effect is really weird…

  1. First make sure the top and bottom of the box are well taped and closed shut
  2. Cut an end out of the box so that we can peer down into the “long view” of the box. In other words, of all the sides of the box, cut out the smallest side.
  3. Attach the board to the side of the box so that it runs lengthwise with the box and extends a foot or so past the end. You can glue it, tie it, or tape it – it just needs to be very secure.
  4. Attach the camera to the board so that it is facing into the box.
  5. Attach the light to the board so that it is also facing into the box. The light will illuminate the inside of the box and allow the camera to get a really good picture of the inside of the box.
  6. Adjust the focus of the camera (use the camera’s macro mode if needed) and make sure the light really lights the inside of the box well.
  7. Drop some items into the box. You can drop coins, car keys, little toys, whatever.
  8. Now pick the box up and hold it so the items drop to the “side” of the box (rather than sitting on the bottom).
  9. Turn the box around so the items slide down one side of the box onto the next side.
  10. Shake the box so the items bounce around inside the box. Try different shakes and jerks of the box so you can go back and watch all the different movements afterward.
  11. Now go back and watch the film. You’ll be surprised to see the objects “climb” the walls of the box, slide across the ceiling, and “float” (when you shake it) in space. The effect happens because the viewer’s perspective is different from what they expect. The stationary camera, attached to the box, is not typically the way we are used to seeing things!

Interesting notes about gravity

Did you know that if you could get to the center of the Earth and could survive there (it is hot, hot, hot), you would experience weightlessness. That’s because the force of gravity would be the same in all directions and effectively cancel each other out. With a net force of zero, you would be weightless (but hot).

Interesting note about being weightless: Being in a weightless environment produces some pretty interesting effects on a person’s body. Our bodies are used to the gravitational pull on Earth. If you change that up, interesting things happen.

The most common problem people experience after being in a weightless environment is, strangely enough, sickness. This is known as space adaptation syndrome (SAS), and symptoms include dizziness, headaches, and vomiting. Typically, these effects only last for a few days.

NASA refers to the length of time it takes to recover from these symptoms as a “Garn,” named after United States Senator Jake Garn, who flew on the Space Shuttle and holds the record for the longest space sickness. Seriously.

The worst effects of long-term weightlessness are the shrinking of muscles and weakening of the skeleton, a condition known as spaceflight osteopenia. To lessen these effects, astronauts can exercise while in space. In a weightless environment, the cardiovascular system (heart) weakens, resulting in a slower production of red blood cells, and the immune system weakens, making it easier to get sick. Other negative effects of weightlessness include runny nose, insomnia, and increased flatulence (so be prepared to stand clear of returning astronauts!).

What happened to Senator Garn in space

Senator Jake Garn, who was a member of the U.S. Senate, flew into space on the Space Shuttle Discovery in April 1985. His mission was to study the effects of spaceflight on the human body. During the mission, Senator Garn experienced space adaptation syndrome, which is a type of motion sickness that affects some astronauts. He had severe nausea, headaches, and dizziness.

Despite his illness, Senator Garn continued to perform his duties as a payload specialist, which included conducting experiments and taking photographs of Earth from space. After returning to Earth, Senator Garn became an advocate for the U.S. space program and continued to support NASA’s efforts to explore space.

Experiment Supplies

Supplies: Tape, Cardboard box, Video camera, Wood board, Flashlight

Image Credits

In-Article Image Credits

Peter Diamandis in ZERO-G via Wikimedia Commons by Pdiamandis with usage type - Public Domain. September 10, 2006

Featured Image Credit

Peter Diamandis in ZERO-G via Wikimedia Commons by Pdiamandis with usage type - Public Domain. September 10, 2006

 

Geeks talk back