Physics Stack Exchange is a question and answer site for active researchers, academics and students of physics. It's 100% free.

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Are there fundamental big questions in physics that most scientists encounter no matter what they're working on, or are most questions details of smaller subtopics? What are the great unknowns of our day?

Sorry in advance if my question is too general. I told my kid that there are some things science still doesn't have theories for, and she asked "like what" and I said I wasn't sure, so I'm asking here. So much science has been done since I was in school that I don't know what all has changed. I think what she's after is some real mysteries to wonder about, ones that don't have generally accepted theories yet.

share|cite|improve this question

closed as not constructive by John Rennie, David Z Feb 19 '13 at 8:48

As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance.If this question can be reworded to fit the rules in the help center, please edit the question.

Although sometimes more mathematics than physics, take a look at the millenium problems ( As a fluid dynamicist I think in particular the existence of a general solution to the Navier-Stokes equations is a big and continuously present problem for many physicist and fluid dynamicist – Michiel Feb 19 '13 at 7:54
According to which physical branch? Something may be very important for quantum physician, but it could also be uninteresting for another physician. – hkBattousai Feb 19 '13 at 8:17
@hkBattousai I didn't know medical doctors used quantum mechanics :P. – jld Feb 19 '13 at 8:42
Possible duplicate: – Qmechanic Feb 19 '13 at 8:52