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Section 1.5: Getting Data Out

Please wait for the animation to completely load.

In Section 1.2 you learned about units and how to click-drag in an animation to get data from the animation. Here we will discuss several other ways in which data are depicted in animations. Restart.

Press the "play" button to begin. Shown in the animation (ħ = 2m = 1) is the probability density corresponding to an accelerating Gaussian wave packet. When you press the "play" button, the packet will move across the screen in a predefined way (obeying the rules of quantum mechanics).  Along with the probability density are depictions of the packet's average position: as an on-screen numerical statement, as data in a table, and as a function of time on a graph. You may of course click-drag in the animation to measure average position (since a Gaussian is symmetric about its maximum value) and amplitude as well.

Why do we show all of these different representations?  Because they provide complementary ways of thinking about the phenomena.  Click Restart and play the animation again. Notice how the different representations of the motion change with the motion of the packet.  With a lot of practice, physicists can look at the motion of an object and can tell you the various properties of the motion. How do we do that?  By having different mental representations in our heads. Specifically,

In practice, we will never set up an animation to give you all of these depictions simultaneously. We usually pick one or two representations that best represent the phenomena.

Note that some animations depict motion that started before the animation begins and continues beyond the time that the animation ends. In the animations on this page, the packet starts at rest at t = 0 but continues its motion beyond the t = 5 mark when the animation ends.

The OSP Network:
Open Source Physics - Tracker - EJS Modeling
Physlet Physics
Physlet Quantum Physics