- bug fixes
- retina support

### App Description

** Now with 3D display of warped space **

Gravity Lab is a gravity simulator for iPad. It allows you to create dozens of particles with different masses and different initial velocities by simply tapping the screen or drawing a velocity vector. The positions and velocities of all the particles are recalculated in real time. According to Newton's law of universal gravitation, every massive body in the universe influences every other massive body, and it works exactly the same in Gravity Lab. You can toggle a switch to show the acceleration vectors of the bodies, which are proportional to the forces between the bodies and inversely proportional to their masses.

Gravity Lab is a great tool to explore the laws of nature that govern everything in the universe. By being gravitationally attracted to a rock weighing more than 13,000,000,000,000,000,000,000,000 lbs (or almost 6,000,000,000,000,000,000,000 metric tons), we are not very good at intuitively understanding the universal effects of the gravitational forces. For us, standing here on Earth, gravitational forces always point down. Should you, however, spend a day as a heavenly body, your perception would be completely changed.

Gravity lab is a perfect aid for anyone seeking a deeper understanding of physics, or just willing to play around with their own simulated universe.

Gravity Lab includes a short 4-page guide explaining the Newton's law of universal gravitation, the first two of the three Kepler's laws of planetary motion and the concept of gravity assist in spaceflight. All these concepts can be demonstrated using Gravity Lab.

What you can do:
- create your own solar system
- demonstrate complex interaction patterns of multiple massive bodies
- collide massive bodies and demonstrate the conservation of momentum
- display vectors of acceleration due to gravitational forces and observe the acceleration of orbiting bodies
- observe first two of the three Kepler's laws of planetary motion
- demonstrate gravitational slingshot (gravity assist) for increasing the spacecraft's velocity
- observe effects of changing gravitational constant on the gravitational field using "Gravity well" mesh type

How to use
- create bodies by selecting the desired mass and drawing a vector of initial velocity using your finger
- tap to create a stationary body
- pinch to zoom
- use two fingers to pan
- toggle Acceleration on/off to display direction and relative size of body's acceleration (same as the direction of the forces)
- reset particles and zoom level

(click to enlarge)

### App Changes

• March 24, 2012 New version 1.2
• June 10, 2012 Price decrease: \$1.99 -> FREE!
• June 11, 2012 Price increase: FREE! -> \$1.99
• September 02, 2012 Price decrease: \$1.99 -> FREE!
• September 10, 2012 Price increase: FREE! -> \$1.99
• December 10, 2012 Price decrease: \$1.99 -> \$0.99
• December 18, 2012 Price decrease: \$0.99 -> FREE!
• December 22, 2012 Price increase: FREE! -> \$1.99
• October 05, 2013 Price decrease: \$1.99 -> FREE!
• October 12, 2013 Price increase: FREE! -> \$1.99
• February 11, 2015 Price decrease: \$1.99 -> \$0.99
• May 29, 2015 New version 1.2.2