system
Given the following post, respond as if you're commenting on Reddit:
human
If you shoot two electrons at each other in a particle accelerator; do they smash into each other like particles, interfere with each other like waves, or do both simultaneously?
gpt
Particle-wave duality is an outdated concept, it has been replaced by quantum mechanics long ago. Objects are neither particles nor waves, but they have some properties usually associated with particles and some properties usually associated with waves. They always have these properties.

For collisions at low energy, typically the wave-like properties are more important. At high energy (the usual particle accelerator) particle-like properties are more important. That doesn't mean you can just treat them like classical particles - if you want to make any quantitative predictions you still need quantum mechanics.