# How to play with the new balls ( ! )

I started playing the first puzzle after the tutorials. But it had a NEW color ball in it, a yellow ball with an exclamation point. These balls refused to get their color changed. This was not covered in the tutorial, I don’t know what these mean. There was no Help link in the upper right to go over the rules of the game. Not fair to change the rules and not teach me about it. What do the new (!) balls mean, and how do I work with them?

Also there should be lectures on minimizing energy, e.g. trying to get it to be as far negative as possible, for the highest score. This was not covered. Also, does the energy change as I hover over a ball and think about changing it? I need to be able to compare the new thing that I might do, with the current state. Thanks.

the balls with an ! are ‘locked’ and can’t be changed - they are an extra restriction that the molecule has to obey.

negative energy is generally something to aim for in the challenges

energy doesn’t change until you change a base - you can always use the ‘back arrow’ to undo (and then the forward arrow to redo) a group of changes to look at the effects of energy for a particular set of changes.

hope that’s some help

The keyboard shortcut for undo is ‘z’.

Also, remember that the point is not to minimize energy, but rather to find the sequence which folds into the target shape. In fact, the top players who play in the lab – where we synthesize player designs – have found that “energy” is not a very good proxy for folding accuracy, in practice.

Okay, first thing to notice is that there are actually multiple different colored balls with exclamation point (!), they are not all yellow. There are red and green ones, also presumably blue ones. They don’t have the fancy design on them,
but you can still see what they are from their colors.
Assuming the color code is consistent, the exclamation point, which is probably an icon for a keyhole or a key, then means that that color ball is locked and can’t be changed. I’ll take that.

Continuing on with the first “Loop Strategy–Learn About the 1-1 Loop”, in target configuration counting down from the top, we have mandatory solution
G-red = C-green locked, forced.
U-blue = A-yellow Forced move, as yellow is locked, blue only glue to it
A-yellow A-yellow Doesn’t matter, as long as they both don’t attract
G-red = U-blue Required move, as 1+ G-U pair is required, and no other chance
u-blue = A-yellow Forced move, as yellow is locked, blue only glue to it
G-red A-yellow Locked
A-yellow - A-yellow Locked

All moves are forced or required.

However, system does not recognize G-U pair fulfillment, and demands that a G-U pair be created before winning and clearing the level.

System also refuses to respect fold into target shape, even though all glued pairings are valid.

Obviously I must be missing something. Either that, or the game win detection logic has a bug in it.

Maybe you’re supposed to fold it into a configuration other that what the target configuration specifies? The topology is not exact? loops could shift up or down, or you can have extra beads hanging off the end? What I have should work, in fact is only real solution if you follow the locks and the target literally; not to have it be recognized is confusing and frustrating.

thanks.

Only works if you change both unassigned middle balls to red. Two yellows don’t work. Two blues don’t work. Two greens recombine in a different shape.
Yellow/blue or blue/yellow flatten out. Yellow/red and red/yellow don’t work.
Yellow/green goes to a different shape. Green/yellow doesn’t work.
Green / blue doesn’t work.

conclusion: Nonintuitive. Third-level details needed to see if it’s going to work or not. Can’t predict ahead of time if something’s actually going to work or not, when it’s on the hairy edge. Not fun. Unproductive use of time. Better to design a computer program to figure out all possible permutations for you, because it looks like that’s what it’s going to take. And this was a simple puzzle with only 14 beads.

will do this professionally if you pay me for the algorithmic research. Let me know. Can’t do this one for fun. Good luck.

Dear Orm,

Thanks for the comments. You’re absolutely right that the tutorials don’t make clear the special role that nucleotides adjacent to the stacks play in stack formation. In fact, we’re rolling out new tutorials (and retiring the loops challenges) to address this important issue.

You’re also right to point out that the tutorials could easily be solved computationally. In fact, solving tutorial-style puzzles is no longer an open scientific problem. They are included in EteRNA only to train players for the lab – where players’ designs are synthesized, and then the community helps find principles which explain the gap between computational folding models (such as in the challenge puzzles) and reality. The lab is thus the heart of scentific knowledge creation in EteRNA. The early puzzles should do a better job to put this into context.