Tunneling ball in 1D collisions
Closed this issue · 7 comments
A user wrote into phethelp:
I think there might be a bug in the Collisions simulation.
Under the Advanved tab, if you choose one-dimension and have three balls
with different masses, say 0.1 kg, 1 kg, and 5 kg, you can see balls
"tunneling" through each other so that if they start out 1, 3, 2 you
might get 3, 1, 2 and then it will switch back to 1, 3, 2 or might
change to 3, 2, 1 (where the numbering is the ordering of the balls L-R
inside the rectangle). It happens mostly when the balls are moving fast,
although they never are traveling fast enough to approach speeds for QM
tunneling.I bring it up because it raises a question on whether or not this bug
might be affecting the simulation in other areas. If I assign it as an
online "lab" activity for a physics course, but the data is corrupt, it
makes it difficult for students to deal with the simulation data.
I was able to reproduce this bug in Flash if the initial velocities are high. It's also possible to do in the HTML5 version.
This was addressed in #123, which has now been merged into master. Back to @arouinfar for review.
Master is looking really good!! I haven't been able to reproduce the tunneling, but I think it would be good for QA to check on this when it goes up for testing.
Haven't reproduced in dev.10
Great catch!. It might be a separate issue though. @arouinfar what is your verdict?
Nice find @brooklynlash. I think @KatieWoe is correct. This looks like a slightly different issue, so I've opened #179.