## Introduction: How to Make a Newton's Gravity Puzzle

The Newton's Gravity Puzzle is a very simple puzzle. The objective is to remove the center piece while keeping the puzzle on a level surface. No tools can be used to remove it, only your body and the puzzle itself.

Here are the steps to make your own puzzle along with the solution at the end.

Materials:

• Wood
• Paint

Tools:

## Step 2: Inner Piece

This inner piece of the puzzle is made from an old cedar 4x4. However, any light would work here. I mounted it in the nova chuck and turned a cone on the end then turned it round to a diameter of 1 in.

Remove the piece from the lathe without parting it off.

## Step 3: Turn the Outer Shell

Turn the shell between centers then mount it in the nova chuck. Hollow out the center just larger than the inner piece. You want between 1/16 and 1/8 inch of clearance all the way around. This hole should be about 1 1/4 in. deep. Once the hole is at the correct depth, turn to the final diameter of 1 3/4 in and add a chamfer to the edge if you like.

Part it off at a length of about 1 1/2 in.

## Step 4: Cut the Inner Piece to Length

Once the shell is parted off, you want to cut the inner piece to the correct depth. The edge of the inner piece should be just below the shoulder of the shell. It should sit low enough in the shell that the inner piece can't be grasped with fingernails.

## Step 5: Sand and Paint

Sand and apply any color paint you like. I went with the traditional red of the original Newton's Gravity Puzzle.

## Step 6: How Does It Work?

Atmospheric pressure is present around every object on earth. The Newton's Gravity Puzzle is solvable through creating a difference in pressure above and below the inner piece. To overcome the acceleration of gravity, a gentle blow directly on the puzzle will decrease the pressure above the cylinder sucking it out and solving the puzzle.