Free interactive physics simulation apps for Windows

Select a topic from the menu above to access the dedicated download pages for each of these interactive physics apps:
• Classical mechanics
• Quantum mechanics
• Special relativity
• General relativity

In these apps, you can explore and experience physics firsthand:
• Understand how physical laws function in real-world scenarios.
• Discover how parameters, initial values, and physical constants influence system changes (such as motion and energy).
• Compare different physical theories through interactive visualization.

Release Schedule & Compatibility
The simulation apps are currently being released successively for Windows (32 and 64-bit), following a transition to a new, uniform layout. Check back regularly as new simulations are added to the collection.

Future plans include making these simulations available for Android, iPad (iOS), and macOS.
All apps are developed using the Embarcadero Delphi Firemonkey platform to ensure high performance and reliability.


The story behind the name: Panta Rhei
“Panta Rhei ouden menei” — Everything flows, nothing is permanent.
This statement is attributed to the Greek philosopher Heraclitus (c. 540–480 BC). Conversely, his contemporary Parmenides claimed: “The universe is immovable.”
While Parmenides placed emphasis on pure logic and reason—elements often associated with the domain of mathematics—Heraclitus’s perspective is more applicable to the world of physics.
Most physical theories and models deal with motion or change (position, velocity, momentum, energy). It is this dynamic nature of the universe that inspired the name Panta Rhei for this collection of simulations.

Curious about the fundamental questions behind these simulations? Read more about the motivation behind Panta Rhei