Do you ever come across questions that you can’t find the awnser for? And if you do, how often do you come across them?

Question: Do you ever come across questions that you can't find the awnser for? And if you do, how often do you come across them?
- Keywords:
  research,
  science
Asked by jetfire to Marcus on 12 Nov 2012.
- Marcus Wilson answered on 12 Nov 2012:
  
  all the time its almost embarassing! Thats the best bit about being on the frontline of science; you are seeing stuff that no-one else has seen before, and this raises lots of questions. A lot of the time you have theories about what the answer might be, and you can test them out.
  
  In the end, despite having evidence for our answers, we are never entirely sure. we are all working on theories, not definitive answers.

Question: Do you ever come across questions that you can't find the awnser for? And if you do, how often do you come across them?