What are some open problems in physics that undergraduates can tackle?

[skeer]

Are there any open problems in physics that could be tackle by undergraduates? If there are, where can I find them?
These problems should require some intermediate understanding of Physics. It could be a problem forgotten by its insignificance or something that just requires a ingenious way to solve it.

 

[Dr. Courtney]

You mean theory?

There are lots of practical problems on the borderline between physics and chemistry or physics and engineering.

A lot require some experimental work also.