UMaine-Penn-State-paper-feature (IMAGE)
Caption
A graphic illustrating the four possible interactions between two particles, where the arrows indicate the force experienced by the particle of that color due to the gradient surrounding the particle of the other color. The interactions shown in the upper left-hand and lower right-hand corners illustrate reciprocal interactions where the two particles attract each other, or where they repel each other, respectively. The upper right-hand graphic illustrates a situation where the red particle attracts the blue particle, but the blue particle repels the red particle. The lower left hand graphic illustrates a situation where the red particle repels, but is attracted to, the blue particle. Graphic courtesy of R. Dean Astumian.
Credit
R. Dean Astumian
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License
Original content