topology puzzle - without cut the rope, separate two rings hello I wonder whether this puzzle is possible to solve.
if possible, what kind of thing should I learn to solve this?
the problem is make left one to right one without cut the rope
only stretch and bending are allowed
I found out this puzzle here->(www.ocf.berkeley.edu/~wwu/riddles/hard.shtml/)


I wish this problem lead me to learn math intuitively.

Here's one way to think of it.
Call the loops $L_1$ and $L_2$, joined by the stem which attaches to $L_1$ at $S_1$ and $L_2$ at $S_2$.  You will notice there is a point $A$ where $L_1$ crosses and is above $L_2$ and another point $B$ where $L_1$ crosses and is below $L_2$.
Now contract the stem until it vanishes so that $S_1$ and $S_2$ become a single point $S$ and you will see that one of the points $A$ or $B$ will also move to $S$ under this deformation.
If you try to draw the two rings now joined at the single point $S$ you will see they are no longer linked - there is only one crossing point now so you simply have two rings sitting on top of one another joined at a point.  
All you need to do now is stretch out the stem again and the rings will look like the second picture.
